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Collaboration between Iridium Clusters and the {111} Dominant Facet of Cu2O for N Triggering Efficient 2 Photofixation
Wensheng Zhang, Qingmei Tan, Tianren Liu, Zhishan Liang, Youlin Huang, Ying He, Dongxue Han,* Dongdong Qin, and Li Niu
Cite This: ACS Materials Lett. 2024, 6, 3007−3015 Read Online ACCESS Metrics & More Article Recommendations * sı Supporting Information
ABSTRACT: The exploration of advanced photocatalysts for efficient N2 reduction reaction (NRR) by integrating facetengineering and realistic N2 active sites is very promising, but it remains a challenge due to the absence of rational structural design and atomic-level insights into molecular N2 activation. Herein, the same main group transition metal (e.g., Co, Rh, and Ir) clusters were ingeniously modified onto the dominant {111} crystal facet of Cu2O nanocrystal, aiming to track the synergistic effect of various N2 active sites and facet-engineering for efficient N2 photofixation. Intriguingly, further theoretical studies reveal that the incorporating Ir clusters can improve light absorption ability, accelerate photogenerated charge separation and transfer, and lower the reaction energy barrier, thereby expressively promoting the real photoreactivity. The present work offers a promising approach to cooperatively regulate the facet-engineering and N2 active centers at the atomic level, expecting to guide innovative design of smart NRR systems.
he synthesis of artificial ammonia (NH3) and its derivatives through reducing nitrogen (N2) is essential T for agricultural and industrial production, as NH3 is an important component of fertilizers and life forms.[1][−][3] Because of its large hydrogen capacity (17.6 wt %), NH3 has sparked considerable attention as a hydrogen storage material.[4][,][5] However, efficiently utilizing atmospheric N2, which comprises 78% of air, is challenging due to its strong N�N bond.[6][,][7] The current industrial Haber−Bosch process, which relies on high temperatures and pressures, is costly, is energy-intensive, and emits greenhouse gases.[8][,][9] Solar-powered N2 photofixation, using renewable solar energy and H2O, offers a green and sustainable alternative for NH3 synthesis.[10][−][12]
As is well-known, the catalytic properties are linked to crystal facets, making metal oxide nanocrystals ideal for studying structure−performance relations.[13][,][14] Shape-controlled synthesis maximizes exposure of reactive facets for photocatalysis.[15][,][16] Different crystal facets of semiconductors like TiO2,[17][,][18] BiVO4,[19][,][20] BiOCl,[21][,][22] and Cu2O[23][,][24] exhibit varying photocatalytic performance due to their unique surface atom arrangements. Among them, Cu2O, synthesized easily under mild conditions, boasts low toxicity, high abundance, environmental acceptability, and a high light absorption
coefficient.[25][,][26] With tailored (100), (110), and (111) facets, Cu2O nanocrystals exhibit facet-dependent photocatalytic properties.[27] Previous research shows that their morphology and facets significantly influence photoelectronic properties, altering catalyst activity.[28][,][29] For example, Cu2O cuboctahedrons outperform cubes and octahedrons in photocurrent output due to facet-dependent charge separation.[30] Wu et al. found the (110) facet of Cu2O nanoparticles has higher photocatalytic activity for CO2-to-methanol conversion.[24] Xiong et al. decorated Pd nanoparticles on Cu2O facets, revealing electron transfer is closely related to crystal planes.[31] Given its properties, Cu2O is a promising candidate for solardriven N2 reduction to NH3.[32] However, there are still few reports that have explored the crystal-plane effects of Cu2O during N2-to-NH3 conversion.
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Received: March 19, 2024 Revised: June 7, 2024 Accepted: June 7, 2024 Published: June 13, 2024
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Herein, we synthesized cubic Cu2O-100 and octahedral Cu2O-111 particles to track and screen their N2 photofixation reactivity. Consequently, the Cu2O-111 nanocrystal demonstrated a better NRR activity. However, its activity was limited by few surface sites. Intriguingly, we further attempted to modify the VII group transition metals (Co, Rh, Ir) on Cu2O111. As a result, the Cu2O-111-Ir catalyst exhibited superior Ngcat.2-photofixation−1 h−1. The performancetemperature-programmedwith a NH3 yielddesorptionof 173.8(N μ 2gTPD) data showed the integrating Ir clusters on Cu2O-111 as active sites can achieve high adsorption and activation of N2 molecules. Most importantly, the photoelectric characterizations and density functional theory (DFT) calculations revealed the incorporated Ir clusters can enhance light absorption capacity, improve the efficiency of photoinduced charge separation and transfer, and effectively reduce the activation energy barrier, thus significantly accelerating the reaction kinetics of NRR. This work provides a promising approach for exploring smart NRR catalysts.
The surface atomic arrangement of semiconductors determines their properties. We examined the {100} and {111} facets of Cu2O, revealing that {111} facets possess more unsaturated Cu coordination for potential NRR sites (Figure 1a). SEM (Figure 1b,c) and TEM (Figure 1d,g) images
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Figure 1. Morphology and structure of the Cu2O particles. (a) Atomic structure model of Cu2O with well-defined (100) and (111) facets. (b, c) SEM images, (d, g) TEM images, (e, h) HRTEM images, and (f, i) SAED patterns of Cu2O-100 and Cu2O111 samples.
demonstrate that Cu2O-100 has a cubic structure with (100) facets, while Cu2O-111 holds an octahedral structure with (111) facets. HRTEM images display lattice fringes of 0.21 and 0.25 nm (Figure 1e,h), corresponding to (200) and (111) planes of Cu2O, respectively.[33] The selected area electron diffraction (SAED) pattern of Cu2O-100 particles displays clear diffraction spots with identified diffraction planes of (110) and (200) with a zone axis of [002] (Figure 1f), which proves that the highly exposed crystal plane of the Cu2O cube is the (100) facet. And Figure 1i displays strong diffraction spots from (110), (211), and (101) planes of Cu2O along with
a [111] zone axis, indicating the dominant exposed surface of Cu2O-111 is the {111} facet.[34] At the same time, the XRD patterns matched the PDF standard card data (05-0667), indicating that both samples were cubic phase with good crystallinity (Figure S5). The above data confirm the successful construction of Cu2O nanocrystals with two morphologies exposed with {100} and {111} crystal planes, respectively.
To identify and visualize the related Cu2O-111-Ir samples, TEM, high-angle annular dark-field scanning TEM (HAADFSTEM), energy dispersive spectrometer (EDS) element mapping, and X-ray absorption fine structure (XAFS) characterizations were conducted. As shown in Figure 2a, the Cu2O-111-Ir sample exhibits a regular octahedral shape, and some uniformly distributed nanoclusters can be clearly observed on the surface. It can be definitely seen from the HRTEM image and particle size distribution of Cu2O-111-Ir (Figure S6a,b) that the surface-decorated Ir clusters are monodisperse nanodots with nearly spherical shape, and the average diameter is about 0.69 nm. Moreover, we implemented EDS element mapping on Cu2O-111-Ir, as clarified in Figure 2b,c. The signals of Cu, O, and Ir element mapping match well with the HAADF-STEM image, delineating the pattern of the entire architecture, which proves the successful preparation of the Cu2O-111-Ir catalyst. Analogously, the as-prepared Cu2O100-Ir, Cu2O-111-Co, and Cu2O-111-Rh composites are clearly visualized and identified by TEM and STEM-EDS mapping (Figure S7−S9).
The oxidation states of Ir in the Cu2O-111-Ir catalyst can be revealed by the X-ray absorption near-edge structure (XANES). The spectra of XANES demonstrate that the absorption edge of the Ir L3-edge for Cu2O-111-Ir was placed between that of Ir foil and IrO2 (Figure 2d), indicating the valence state of Ir is between 0 and +4, which may be attribute to the formation of the Ir−O or Cu−Ir coordination bond at the Cu2O (111)/Ir heterointerface by Ir atoms on the surface of Ir clusters. Meanwhile, the local coordination environment was examined using extended X-ray absorption fine structure (EXAFS) measurements, and the fitting curves are displayed in Figure S10. As for the Fourier transformed (FT)-EXAFS spectra of Figure 2e, a notable peak at ∼2 Å was observed in the curve of Cu2O-111-Ir corresponding to the Ir−O bond,[35][,][36] and the prominent peak located at ∼3 Å could be assigned to the Ir−Ir bond.[37] More importantly, the abundant Ir−O coordination forms at the Cu2O-111/Ir interface, making the architecture of Cu2O-111-Ir have good stability. To clarify whether the loaded Ir species are IrOx, we further characterized the elemental composition and chemical state of the catalyst surface by XPS before and after loading the Ir species onto the Cu2O-111 nanocrystal. The Cu[+] signals of Cu2O are represented by the peak locations at ∼951.56 eV and ∼931.67 eV in the Cu 2p spectra of the Cu2O-111 sample (Figure 2f), whereas the Cu[2+] signals of CuO are represented by the peaks at ∼954.44 eV and ∼934.12 eV, which may be related to partial surface oxidation on the (111) facets of Cu2O. The peaks at ∼529.31 eV, ∼530.73 eV, and ∼532.34 eV in the high-resolution XPS spectra of O 1s (Figure 2g) are designated to oxygen related to O species in the chemisorbed oxygen, lattice oxygen, and metal hydroxide species. Noticeably, the binding energies of Cu 2p and O 1s are shifted to a greater value for the Cu2O-111-Ir sample, indicating a strong interaction between Ir species and Cu2O support.[38][,][39] Regarding the Ir 4f spectrum of the Cu2O-111-Ir sample (Figure 2h), we observe that it lies between Ir[0] (metallic state)
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Figure 2. Structure properties of the Cu2O-111-Ir photocatalyst. (a) TEM image of Cu2O-111-Ir. The HAADF-STEM (b) images of Cu2O111-Ir architecture and the corresponding STEM element mappings (c) for Cu, O, and Ir. The Ir L3-edge XANES (d) and EXAFS (e) spectra of Ir foil, standard IrO2 powder, and as-prepared Cu2O-111-Ir sample. The high-resolution Cu 2p (f), O 1s (g), and Ir 4f (h) XPS spectra for Cu2O-111 and Cu2O-111-Ir samples. (i) N2-TPD spectra of the as-prepared various catalysts.
and Ir[4+] (high price state) and that its position tends more toward Ir[0] . This observation strongly implies that the principal morphology of the Ir species on the surface of Cu2O-111-Ir is the Ir metallic cluster. The phenomenon of partial Ir displaying a positive valence is likely due to the formation of Ir−O bonds between Ir and the lattice oxygen in the substrate Cu2O, and this interaction causes the electronic state of some Ir to shift, thus showing the characteristics between the metallic state and the hypervalent state.[40]
Since the chemisorption of N2 is the initial step toward NRR,[41][,][42] the N2 chemisorption capacity of the catalysts were examined by N2-TPD with a mass detector, as illustrated in Figure 2i. Both Cu2O-100 and Cu2O-111 nanocrystals possess a relatively weak N2 chemisorption. After the metal Ir clusters were integrated, the catalysts elaborate a significant enhancement in the chemisorption of N2, especially for the Cu2O-111Ir catalyst. Gratifyingly, as evidenced in Figure S11, the N2 desorption peak of the Cu2O-111-Ir sample is also stronger compared to that of Cu2O-111-Co and Cu2O-111-Rh.
Accordingly, the Cu2O-111-Ir catalyst with more chemically adsorbed N2 is responsible for the prominent NRR performance.
The optical features of various samples were examined by using UV−vis diffuse reflection spectra (Figure 3a). Intriguingly, Cu2O-111-Ir and Cu2O-100-Ir exhibit a greater light absorption ability than those of Cu2O-111 and Cu2O-100, which might be attributed to the formation of metallic gray or lattice plasmons of the modified Ir clusters.[43][,][44] Concomitantly, the photocurrent response and electrochemical impedance spectroscopy (EIS) were used to probe the migration and separation efficiency of photogenerated charges in various catalysts. As evidenced, the Cu2O-111-Ir possesses a considerably higher photocurrent intensity than that of other samples, suggesting superior carrier separation conditions. Figure S12 depicts that Cu2O-111-Ir possesses a notable decrease in transient photocurrent intensity under a N2 atmosphere compared to an Ar atmosphere. This significant reduction strongly proves that some photogenerated electrons
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Figure 3. UV−Vis diffusive reflectance spectra (a) and transient photocurrent response (b) of different samples. (c) Evolution of photocatalytic NH3 levels in relation to light irradiation times. (d) Photocatalytic NH3 production rate for various catalysts. (e) Photocatalytic NH3 synthesis activity of Cu2O-111-Ir obtained from different conditions. (f) Photocatalytic cycling activity tests of Cu2O111-Ir. (g) Schematic of the in situ FT-IR setup. (h) The in situ FT-IR spectra of N2-photofixation over Cu2O-111-Ir sample. (i) The 3D and 2D contour color map corresponds to line plots of in situ FT-IR spectra over Cu2O-111-Ir sample.
of Cu2O-111-Ir with abundant N2 reactive sites (e.g., Ir culsters) participate in the NRR reaction.[45] In essence, the smaller the EIS semicircle, the greater the mobility and separation of photogenerated carriers.[46] From Figure S13a, the semicircular radius of Cu2O-111-Ir in the high-frequency area is smallest compared to other catalysts, meaning that Cu2O111-Ir presents a lower interface resistance and higher charge transfer ability. To investigate the kinetic behaviors of carriers in greater depth, steady-state photoluminescence (PL) measurements were conducted (Figure S13b). The significant reduction in the intensity of Cu2O-111-Ir, as compared to that of Cu2O-100, Cu2O-111, and Cu2O-100-Ir, indicates effective separations of photogenerated electron−hole pairs.[47][,][48] This was attributed to Ir nanoclusters on Cu2O-111, improving light absorption, conductivity, and carrier separation and thus enhancing photocatalytic performance.
To assess the N2 photofixation activities of different catalysts, the catalysts were dispersed in N2-saturated water under full-spectrum irradiation, and the generation of NH3 was
determined by ion chromatography. Nearly no NH3 was identified with N2 over all of the samples in the dark condition, as illustrated in Figure 3c. As the light experiment progressed, the photocatalytic NH3 generation rates of all catalysts gradually increased with time in the N2 atmosphere. As shown in Figure 3c,d, the Cu2O-100, Cu2O-111, and Cu2O100-Ir demonstrate very low N2 reduction abilities and a small amount of NH3 formation. Encouragingly, the well-designed Cu2O-111-Ir exhibits greatly promoted NRR performance, with a NH3 yield up to 173.8 μ g gcat.−1 h−1, which is about 10.7, −1 4.2, and 3.3 times higher than that of Cu2O-100 (16.2 μ g gcat. h[−][1] ), Cu2O-111 (41.8 μ g gcat.−1 h−1), and Cu2O-100-Ir (52.3 μ g gcat.−1 h−1), respectively. Several rigorous contrast experiments were carried out to investigate the NRR activity of Cu2O-111-Ir in different conditions (Figure 3e). When the NRR process was conducted under Ar atmosphere (without N2), under dark or without catalyst, only trace NH3 could be detected, suggesting that the produced NH3 over the Cu2O-
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Figure 4. DFT calculations. (a) DFT-established structures and N2 adsorption configuration of Cu2O-100-Ir and Cu2O-111-Ir. (b) Adsorption energies and N−N distance of N2 over the Cu2O-100-Ir and Cu2O-111-Ir catalysts. (c) Differential charge density of Cu2O-100Ir- ***** N2 and Cu2O-111-Ir- ***** N2 (yellow and green colors illustrate an enhancement and reduction in electron density, accordingly). (d) The N−N bond distance between the free N2 and intermediates from the beginning of hydrogenation to the release of the first NH3 molecule over Cu2O-111-Ir catalyst. (e) Gibbs free energy diagrams of N2 photofixation through different paths over Cu2O-100-Ir (blue line: the optimal NRR process, orange line: other possibilities of NRR paths); the insets are optimized atomic structure models. (f) Preferred converting N2 to NH3 procedure on the Cu2O-111-Ir catalyst. Color code: Cu (red), O (brick red), Ir (red), N (blue), and H (green) atoms, respectively.
111-Ir catalyst indeed originates from the photocatalytic reaction.
To delve deeper into the efficiency of light energy utilization, the apparent quantum efficiency (AQE) of the catalysts serves as a key metric, indicating the extent to which light-chemical energy is converted into chemical products.[49][−][51] As illustrated in Figure S14, the apparent quantum efficiency (AQE) of the Cu2O-111-Ir nanocatalyst for NH3 production was evaluated
under varying wavelengths of monochromatic light (e.g., 350, 380, and 470 nm). Notably, at a wavelength of 350 nm, an AQE of approximately 0.067% was achieved, indicating an acceptable utilization of solar energy (Table S2). As demonstrated in Figure S15c, no N2H4 was identified during the process over different catalysts, indicating high selectivity for NH3 synthesis. Such a satisfying result for the Cu2O-111-Ir catalyst might be attributed to the crucial and synergistic role
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of Ir clusters and dominant crystal plane effects in N2 photofixation, which results in outstanding performance compared to previous reports (see Table S3). Over five testing cycles, the high photocatalytic stability of the Cu2O-111-Ir hybrid was confirmed (Figure 3f), with no substantial decline in N2 photofixation efficiency detected.
To assess the Cu2O-111-Ir’s photocorrosion, XRD, XPS, and TEM analyses were done before and after photocatalytic NRR (Figure S16). The XRD spectra exhibit a decreased crystallinity to a certain extent, possibly due to Cu2O photocorrosion. The XPS reveals minimal changes in composition and surface states. The microstructure and morphologies of the Cu2O-111-Ir nanocrystal after the pNRR reaction were also evaluated using TEM and STEM element mapping. TEM images and STEM element mapping show a slight deformation in the Cu2O-111-Ir structure (Figure S17a−f), indicating some photocorrosion. Fortunately, the adjustment of Cu2O nanocrystals to a special octahedral structure through facet-engineering and a core−shell architecture formed by modifying metal Ir clusters may inhibit the photocorrosion phenomenon of the substrate Cu2O nanocrystals, so that the overall Cu2O-111-Ir catalyst holds an acceptable photocatalytic activity.[52][,][53]
To confirm whether the designed Cu2O-111-Ir system undergoes a reliable N2-fixation process, the adsorption and activation processes of N2 molecules were investigated by in situ FT-IR (Figure S18 and Figure 3g−i). Several vibration peaks steadily increase with irradiation time from 0 to 30 min under a N2 atmosphere, as illustrated in Figure 3h,i. Peaks at ∼3580 cm[−][1] (i) and ∼3245 cm[−][1] (ii) are easily ascribed to asymmetric ν (N−H) stretching modes of NH3.[54] The absorption peak at around 2210 cm[−][1] (iii) could be assigned to the chemisorption of N2 molecules on the surface of the photocatalyst.[55] The peak located at ∼1571 cm[−][1] (iv) is assigned to the adsorbed NH3, and the increased peak at ∼1408 cm[−][1] (v) could readily be attributed to surface NH4+.56 Furthermore, the band at ∼1080 cm[−][1] (vi) is associated with bending modes of −NH− or −NH2− species, which could be an intermediate in the hydrogenation with N2.[57][,][58] The monitoring of NH3 and other various reaction intermediates ascertains that the N�N bonds can be effectively activated over the Cu2O-111-Ir catalyst in the presence of H2O and light radiation.
To verify the authenticity of the photocatalytic N2 fixation on the Cu2O-111-Ir catalyst, the process was carried out using N2 tagged with the[15] N isotope. The NH4+ that is generated can react with phenol and hypochlorite to make[15] N-labeled indophenol,[59][,][60] which can be accurately measured using a liquid chromatography−mass spectrometry (LC-MS) test. Using[14] N2 as the feeding gas, Figure S19a shows a strong mass spectroscopy signal of the[14] N-labeled indophenol anion at around ∼198 m / z in LC-MS analysis. It is worth noting that when[15] N2 is used as the feed gas, the[15] N labeled indophenol anion exhibits a significantly enhanced mass spectrometry signal at approximately 199 m / z (Figure S19b). The LC-MS signal provides a higher intensity compared to the natural abundance ratio of[14] N to[15] N under 1 h of illumination. These data indicate that the detected generation of NH4+ ions in this work originates from N2 photofixation.
To gain atomic-level insights into the NRR activity of Cu2O111-Ir, DFT calculations were performed. Four catalyst models (Cu2O-100-Ir, Cu2O-111-Ir, Cu2O-111-Co, and Cu2O-111Rh) and their optimized N2 adsorption geometries were
established (Figure 4a and Figure S20). Notably, Cu2O-111Co underwent Co cluster reconstruction due to lattice mismatch (Figure S20).[61][,][62] The N2 adsorption on all surfaces displays a terminal bridging mode (Figure 4a and Figure S21a). The adsorption energy of N2 (see Figure 4b and Figure S21a) on the Ir sites of Cu2O-111-Ir (−1.15 eV) exceeded that on the Ir sites of Cu2O-100-Ir (−0.69 eV), Co sites of Cu2O-111Co (−0.82 eV), and Rh sites of Cu2O-111-Rh (−0.87 eV), indicating its superior N2 adsorption capacity.
To further elucidate the role of Ir sites in weakening adsorbed N2 molecules, we analyzed the bond length of the N�N bond as an indicator of N2 activation. As depicted in Figure 4b, the N�N bond length in N2 adsorbed on the Ir active sites of Cu2O-111-Ir elongates to 1.231 Å, closely resembling the double bond lengths in azobenzene (1.255 Å) and diazene (1.201 Å).[63] In contrast, this significant stretching is not observed on the Ir sites of Cu2O-100-Ir, Co sites of Cu2O-111-Co, or Rh sites of Cu2O-111-Rh (Figure S21b). This indicates that the Ir clusters on the {111} facet of Cu2O nanocrystals play a critical role in the adsorption and activation of the N2 molecules. Furthermore, we investigated the work function, a key parameter reflecting the electron transfer capabilities of photocatalysts.[64][,][65] As shown in Figure S22, Cu2O-111-Ir possesses the lowest theoretical work function (3.65 eV) among the studied catalysts. This lower work function suggests a higher electron transfer efficiency, favoring the transfer of electrons to the adsorbed N2 molecule. Consistent with this, a lower work function is associated with a higher Fermi level, enhancing the interaction between the adsorbate and the substrate.[66] Therefore, the Cu2O-111-Ir catalyst exhibits a higher Fermi energy level, indicating stronger interactions between the Ir sites and adsorbed N2 molecules. This superior electrical feature likely contributes to faster electron transfer and thus enhanced photocatalytic activity for N2 fixation. Additionally, Figure 4c highlights the dense electron density distribution on Cu2O-111-Ir-*N2, with electron accumulation primarily occurring on the Ir clusters. This electron accumulation provides favorable conditions for N2 molecules to acquire electrons during the NRR process.
The Gibbs free energy diagram for the NRR pathway on Cu2O-100-Ir and Cu2O-111-Ir with Ir active sites offers further insights. Initially, the N2 molecule bridging the Ir sites of Cu2O-111-Ir releases 0.57 eV of free energy due to a negative Δ G value, while the corresponding terminal adsorption on Cu2O-100-Ir only releases 0.07 eV (Figures 4e and S23). This initial favorable energy release suggests an easier activation of N2 on Cu2O-111-Ir. Subsequent hydrogenation steps on Cu2O-111-Ir, including *N−N to *NH−N (Δ G = −0.75 eV), *NH−N to *NH−NH (Δ G = −0.41 eV), *NH−NH to *NH−NH2 (Δ G = −0.09 eV), and *NH−NH2 to *NH−NH3 (Δ G = −1.25 eV), proceed smoothly with negative Δ G values (Figure 4e, blue line). In contrast, the optimal NRR pathway on Cu2O-100-Ir exhibits higher reaction energy barriers, especially during the initial hydrogenation step (*N−N to *NH−N), which represents the rate-limiting step for the NRR (Figure S23). The entire reaction process, comprising N2 adsorption, N2 hydrogenation, and NH3 generation, is depicted in Figure 4f. Notably, the N−N bond can be availably stretched over the Cu2O-111-Ir catalyst in the entire hydrogenation process, suggesting that the well-designed photocatalyst is beneficial for the N2 activation (Figure 4d). Taken together, the aforementioned experimental results and calculations manifest that the integrated Ir clusters on the
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{111} dominant facet of Cu2O can spontaneously facilitate the N2 activation and accelerate the reaction kinetics of NRR.
In summary, an ingenious Cu2O-111-Ir catalyst was innovatively developed for evaluating NRR performance under mild conditions, aiming to track the synergy between {111} facets of Cu2O and Ir active centers. Satisfactorily, the well-designed CuNRR property with a NH2O-111-Ir catalyst demonstrates a remarkable3 yield of 173.8 μ g gcat.−1 h−1, which is (16.2Cu10.7-fold, 4.2-fold, and 3.3-fold higher than those of Cu2O-100-Ir (52.3 μ g gcat.−1 h− μ 1),g gcat.Cu−21O-111 h−1), respectively. Simultaneously,(41.8 μ g gcat.−1 h−12),O-100and the present Cu2O-111-Ir possesses a good stability, with nearly unchanged synthesis NH3 activity over five cycling tests. As a benefit from the synergistic effect of exposed {111} facets and Ir active sites, the N�N bond of adsorbed N2 molecules on the Cu2O-111-Ir catalyst could be effectively weakened and activated. More importantly, the DFT calculations provide additional evidence that the cooperative Ir active centers could usefully decrease the activation energy barrier during the NRR process, contributing to markedly promoting the catalytic activity. In an effort to inspire creative design for efficient NRR systems, the present study provides an atomic-level perspective for the coordinated regulation of the facet engineering and N2 active centers.
■ [ASSOCIATED][CONTENT]
* sı Supporting Information
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsmaterialslett.4c00577.
Additional experimental details, materials, and methods, including the materials, apparatus, preparation of Cu2O100, synthesis of Cu2O-111, preparation of the Ir clusters modified Cu2O catalyst, screening and optimization of Cu2O-based photocatalysts, photocatalytic nitrogen fixation, N2 temperature-programmed desorption, in situ Fourier-transform infrared spectroscopy experiments, density functional theory simulations, and Figures S1−S24 and Tables S1−S3 (PDF)
■ [AUTHOR][INFORMATION]
Corresponding Author
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Dongxue Han − School of Civil Engineering c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering and School of Chemistry and Chemical Engineering Guangzhou Key Laboratory of Sensing Materials & Devices, Center for Advanced Analytical Science, Guangzhou University, Guangzhou 510006, P. R. China; orcid.org/0000-0002-7343-2221; Email: dxhan@
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gzhu.edu.cn
Authors
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Wensheng Zhang − School of Civil Engineering c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China
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Qingmei Tan − School of Chemistry and Chemical Engineering Guangzhou Key Laboratory of Sensing Materials & Devices, Center for Advanced Analytical Science, Guangzhou University, Guangzhou 510006, P. R. China
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Tianren Liu − School of Chemistry and Chemical Engineering Guangzhou Key Laboratory of Sensing Materials & Devices,
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Center for Advanced Analytical Science, Guangzhou University, Guangzhou 510006, P. R. China
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Zhishan Liang − School of Civil Engineering c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China
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Youlin Huang − School of Civil Engineering c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China
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Ying He − School of Civil Engineering c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China
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Dongdong Qin − School of Chemistry and Chemical Engineering Guangzhou Key Laboratory of Sensing Materials & Devices, Center for Advanced Analytical Science, Guangzhou University, Guangzhou 510006, P. R. China; orcid.org/0000-0002-8927-8601
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Li Niu − School of Civil Engineering c/o Center for Advanced Analytical Science, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China; School of Chemical Engineering and Technology, Sun Yat-sen University, Zhuhai 519082, P. R. China; orcid.org/0000-0003-3652-2903
Complete contact information is available at: https://pubs.acs.org/10.1021/acsmaterialslett.4c00577
Notes
The authors declare no competing financial interest.
■ [ACKNOWLEDGMENTS]
This research was financially supported by the National Natural Science Foundation of China (22172040, 22227804), National Key R&D Program of China (2022YFD2100304), University-Industry Collaborative Education Program of Ministry of Education of China (220605940231526, 230805940292617), Guangdong Basic and Applied Basic Research Foundation (2023B1515040004), the Department of Science and Techniques of Guangdong Province (2021A1515010180, 2022A156), the Department of Education of Guangdong Province (2023KSY008), Provincial Science and Technology Plan Project (2023AB061), Department of Science and Technology of Xinjiang Autonomous Region (2023AB061), Guangzhou Municipal Science and Technology Bureau (202201020154), Science and Technology Projects in Guangzhou (202201000002), and Tertiary Education Scientific research project of Guangzhou Municipal Education Bureau (202235344, 2023JGZDXM007). We also thank the Shiyanjia Lab platform (www.shiyanjia.com) for providing DFT calculations and TPD experimental testing and analysis services.
■ [REFERENCES]
(1) Gu, H. F.; Li, J.; Niu, X. F.; Lin, J.; Chen, L.-W.; Zhang, Z. D.; Shi, Z. Q.; Sun, Z. Y.; Liu, Q. Q.; Zhang, P.; Yan, W. S.; Wang, Y.; Zhang, L.; Li, P. F.; Li, X. Y.; Wang, D. S.; Yin, P. G.; Chen, W. X. Symmetry-breaking p-block antimony single atoms trigger n-bridged titanium sites for electrocatalytic nitrogen reduction with high efficiency. ACS Nano 2023, 17 (21), 21838−21849.
(2) Guan, Y. Q.; Wen, H.; Cui, K. X.; Wang, Q. R.; Gao, W. B.; Cai, Y. L.; Cheng, Z. B.; Pei, Q. J.; Li, Z.; Cao, H. J.; He, T.; Guo, J. P.;
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Letter
Chen, P. Light-driven ammonia synthesis under mild conditions using lithium hydride. Nat. Chem. 2024, 16 , 373.
(3) Ren, G. M.; Zhao, J. Y.; Zhao, Z. H.; Li, Z. Z.; Wang, L.; Zhang, Z. S.; Li, C. H.; Meng, X. C. Defects-induced single-atom anchoring on metal−organic frameworks for high-efficiency photocatalytic nitrogen reduction. Angew. Chem., Int. Ed. 2024, 63 , No. e202314408. (4) Guo, J. P.; Chen, P. Catalyst: NH3 as an energy carrier. Chem. 2017, 3 , 709−712.
(5) Yang, Y. Y.; Jia, H. L.; Su, S. H.; Zhang, Y. D.; Zhao, M. X.; Li, J. Z.; Ruan, Q. F.; Zhang, C.-Y. A Pd-based plasmonic photocatalyst for nitrogen fixation through an antenna−reactor mechanism. Chem. Sci. 2023, 14 , 10953−10961.
(6) Zhang, W. S.; Liu, T. R.; Tan, Q. M.; Li, J. S.; Ma, Y. G.; He, Y.; Han, D. X.; Qin, D. D.; Niu, L. Atomically precise dinuclear Ni2 active site-modified MOF-derived ZnO@NC heterojunction toward highperformance N2 photofixation. ACS Catal. 2023, 13 , 3242−3253.
(7) Zhang, W. S.; Han, D. F.; Dai, M. J.; Fan, Y. Y.; Pan, G. L.; Liang, W. Q.; Zheng, Q. T.; Qin, D. D.; Han, D. X.; He, Y.; Niu, L. Stable Ti[3+] sites derived from the TixOy-Pz layer boost cubic Fe2O3 for enhanced photocatalytic N2 reduction. ACS Sustainable Chem. Eng. 2021, 9 , 15331−15343.
(8) Shang, S. S.; Xiong, W.; Yang, C.; Johannessen, B.; Liu, R. G.; Hsu, H.-Y.; Gu, Q. F.; Leung, M. K. H.; Shang, J. Atomically dispersed Iron metal site in a porphyrin-based metal−organic framework for photocatalytic nitrogen fixation. ACS Nano 2021, 15 , 9670−9678.
(9) Li, P. S.; Zhou, Z. A.; Wang, Q.; Guo, M.; Chen, S. W.; Low, J. X.; Long, R.; Liu, W.; Ding, P. R.; Wu, Y. Y.; Xiong, Y. J. Visible-lightdriven nitrogen fixation catalyzed by Bi5O7Br nanostructures: Enhanced performance by oxygen vacancies. J. Am. Chem. Soc. 2020, 142 , 12430−12439.
(10) Yang, J. H.; Bai, H. Y.; Guo, Y. Z.; Zhang, H.; Jiang, R. B.; Yang, B. C.; Wang, J. F.; Yu, J. C. Photodriven disproportionation of nitrogen and its change to reductive nitrogen photofixation. Angew. Chem., Int. Ed. 2021, 133 , 940−949.
(11) Zhao, Y. X.; Zheng, L. R.; Shi, R.; Zhang, S.; Bian, X. A.; Wu, F.; Cao, X. Z.; Waterhouse, G. I. N.; Zhang, T. R. Alkali etching of layered double hydroxide nanosheets for enhanced photocatalytic N2 reduction to NH3. Adv. Energy Mater. 2020, 10 , 2002199.
(12) Li, H.; Shang, J.; Ai, Z. H.; Zhang, L. Z. Efficient visible light nitrogen fixation with BiOBr nanosheets of oxygen vacancies on the exposed {001} facets. J. Am. Chem. Soc. 2015, 137 , 6393−6399.
(13) Liu, L. C.; Gu, X. R.; Cao, Y.; Yao, X. J.; Zhang, L.; Tang, C. J.; Gao, F.; Dong, L. Crystal-plane effects on the catalytic properties of Au/TiO2. ACS Catal. 2013, 3 , 2768−277.
(14) Li, L. L.; Chen, X. B.; Wu, Y. E.; Wang, D. S.; Peng, Q.; Zhou, G.; Li, Y. D. Pd-Cu2O and Ag-Cu2O hybrid concave nanomaterials for an effective synergistic catalyst. Angew. Chem., Int. Ed. 2013, 52 , 11049−11053.
(15) Zhang, D.-F.; Zhang, H.; Guo, L.; Zheng, K.; Han, X.-D.; Zhang, Z. Delicate control of crystallographic facet-oriented Cu2O nanocrystals and the correlated adsorption ability. J. Mater. Chem. 2009, 19 , 5220−5225.
(16) Zheng, Y. K.; Duan, Z. T.; Liang, R. X.; Lv, R. Q.; Wang, C.; Zhang, Z. X.; Wan, S. L.; Wang, S.; Xiong, H. F.; Ngaw, C. K.; Lin, J. D.; Wang, Y. Shape-dependent performance of Cu/Cu2O for photocatalytic reduction of CO2. ChemSusChem 2022, 15 , No. e202200216.
(17) Yang, H. G.; Sun, C. H.; Qiao, S. Z.; Zou, J.; Liu, G.; Smith, S. C.; Cheng, H. M.; Lu, G. Q. Anatase TiO2 single crystals with a large percentage of reactive facets. Nature 2008, 453 , 638−641.
(18) Wu, X. J.; Li, J. Q.; Xie, S. J.; Duan, P. B.; Zhang, H. K.; Feng, J.; Zhang, Q. H.; Cheng, J.; Wang, Y. Selectivity control in photocatalytic valorization of biomass-derived platform compounds by surface engineering of titanium oxide. Chem. 2020, 6 , 3038−3053.
(19) Li, R. G.; Han, H. X.; Zhang, F. X.; Wang, D. E.; Li, C. Highly efficient photocatalysts constructed by rational assembly of dualcocatalysts separately on different facets of BiVO4. Energy Environ. Sci. 2014, 7 , 1369−1376.
(20) Chen, S.; Huang, D. L.; Xu, P.; Gong, X. M.; Xue, W. J.; Lei, L.; Deng, R.; Li, J.; Li, Z. H. Facet-engineered surface and interface design of monoclinic scheelite bismuth vanadate for enhanced photocatalytic performance. ACS Catal. 2020, 10 , 1024−1059.
(21) Li, M.; Yu, S. X.; Huang, H. W.; Li, X. W.; Feng, Y. B.; Wang, C.; Wang, Y. G.; Ma, T. Y.; Guo, L.; Zhang, Y. H. Unprecedented eighteen-faceted BiOCl with a ternary facet junction boosting cascade charge flow and photo-redox. Angew. Chem., Int. Ed. 2019, 58 , 9517− 9521.
(22) Li, H.; Shang, J.; Shi, J. G.; Zhao, K.; Zhang, L. Z. Facetdependent solar ammonia synthesis of BiOCl nanosheets via a proton-assisted electron transfer pathway. Nanoscale 2016, 8 , 1986− 1993.
(23) Chen, R. T.; Ren, Z. F.; Liang, Y.; Zhang, G. H.; Dittrich, T.; Liu, R. Z.; Liu, Y.; Zhao, Y.; Pang, S.; An, H. Y.; Ni, C. W.; Zhou, P. W.; Han, K. L.; Fan, F. T.; Li, C. Spatiotemporal imaging of charge transfer in photocatalyst particles. Nature 2022, 610 , 296−301.
(24) Wu, Y. A.; McNulty, I.; Liu, C.; Lau, K. C.; Liu, Q.; Paulikas, A. P.; Sun, C.-J.; Cai, Z. H.; Guest, J. R.; Ren, Y.; Stamenkovic, V.; Curtiss, L. A.; Liu, Y. Z.; Rajh, T. Facet-dependent active sites of a single Cu2O particle photocatalyst for CO2 reduction to methanol. Nat. Energy 2019, 4 , 957−968.
(25) Chang, X. X.; Wang, T.; Zhao, Z.-J.; Yang, P. P.; Greeley, J.; Mu, R. T.; Zhang, G.; Gong, Z. M.; Luo, Z. B.; Chen, J.; Cui, Y.; Ozin, G. A.; Gong, J. L. Tuning Cu/Cu2O interfaces for the reduction of carbon dioxide to methanol in aqueous solutions. Angew. Chem., Int. Ed. 2018, 57 , 15415−15419.
(26) Li, H. T.; Zhang, X. Y.; MacFarlane, D. R. Carbon quantum dots/Cu2O heterostructures for solar-light-driven conversion of CO2 to methanol. Adv. Energy Mater. 2015, 5 , 1401077.
(27) Cui, J.; Zhang, X.; Huang, H. W.; Yang, M.; Yang, B.; Yang, Q.; Liang, S. H.; Sun, S. D. Mechanism insight into an unprecedented dual series-parallel photocharge separation in quaternary Cu2O facet junctions. Adv. Funct. Mater. 2022, 32 , 2111528.
(28) Zhao, Z. L.; Wang, X.; Si, J. Q.; Yue, C. T.; Xia, C. G.; Li, F. W. Truncated concave octahedral Cu2O nanocrystals with {hkk} highindex facets for enhanced activity and stability in heterogeneous catalytic azide−alkyne cycloaddition. Green Chem. 2018, 20 , 832− 837.
(29) Zhang, L. Z.; Shi, J. W.; Liu, M. C.; Jing, D. W.; Guo, L. J. Photocatalytic reforming of glucose under visible light over morphology controlled Cu2O: efficient charge separation by crystal facet engineering. Chem. Commun. 2014, 50 , 192−194.
(30) Zhao, H. Y.; Wang, Y. F.; Zeng, J. H. Hydrothermal synthesis of uniform cuprous oxide microcrystals with controlled morphology. Cryst. Growth Des. 2008, 8 , 3731−3734.
(31) Wang, L. L.; Ge, J.; Wang, A. L.; Deng, M. S.; Wang, X. J.; Bai, S.; Li, R.; Jiang, J.; Zhang, Q.; Luo, Y.; Xiong, Y. J. Designing p-type semiconductor−metal hybrid structures for improved photocatalysis. Angew. Chem., Int. Ed. 2014, 53 , 5107−5111.
(32) Zhang, S.; Zhao, Y. X.; Shi, R.; Zhou, C.; Waterhouse, G. I. N.; Wang, Z.; Weng, Y. X.; Zhang, T. R. Sub-3 nm ultrafine Cu2O for visible light-driven nitrogen fixation. Angew. Chem., Int. Ed. 2021, 60 , 2554−2560.
(33) Liu, Z.-G.; Sun, Y.-F.; Chen, W.-K.; Kong, Y.; Jin, Z.; Chen, X.; Zheng, X.; Liu, J.-H.; Huang, X.-J.; Yu, S.-H. Facet-Dependent stripping behavior of Cu2O microcrystals toward lead ions: a rational design for the determination of lead ions. Small 2015, 11 , 2493−2498.
(34) Han, S. C.; Hu, X. Y.; Yang, W.; Qian, Q. R.; Fang, X. S.; Zhu, Y. F. Constructing the band alignment of graphitic carbon nitride (gC3N4)/copper(I) oxide (Cu2O) composites by adjusting the contact facet for superior photocatalytic activity. ACS Appl. Energy Mater. 2019, 2 , 1803−1811.
(35) Jiang, K.; Luo, M.; Peng, M.; Yu, Y. Q.; Lu, Y.-R.; Chan, T.-S.; Liu, P.; de Groot, F. M. F.; Tan, Y. W. Dynamic active-site generation of atomic iridium stabilized on nanoporous metal phosphides for water oxidation. Nat. Commun. 2020, 11 , 2701.
(36) Lu, Y. X.; Liu, T. Y.; Dong, C.-L.; Huang, Y.-C.; Li, Y. F.; Chen, J.; Zou, Y. Q.; Wang, S. Y. Tuning the selective adsorption site of
3014
https://doi.org/10.1021/acsmaterialslett.4c00577 ACS Materials Lett. 2024, 6, 3007−3015
ACS Materials Letters
Letter
biomass on Co3O4 by Ir single atoms for electrosynthesis. Adv. Mater. 2021, 33 , 2007056.
(37) Zhang, B. H.; Zhao, G. Q.; Zhang, B. X.; Xia, L. X.; Jiang, Y. Z.; Ma, T. Y.; Gao, M. X.; Sun, W. P.; Pan, H. G. Lattice-confined Ir clusters on Pd nanosheets with charge redistribution for the hydrogen oxidation reaction under alkaline conditions. Adv. Mater. 2021, 33 , 2105400.
(38) Zhang, R. H.; Wang, H.; Tang, S. Y.; Liu, C. J.; Dong, F.; Yue, H. R.; Liang, B. Photocatalytic oxidative dehydrogenation of ethane using CO2 as a soft oxidant over Pd/TiO2 catalysts to C2H4 and syngas. ACS Catal. 2018, 8 , 9280−9286.
(39) Zhang, C. B.; Li, Y. B.; Wang, Y. F.; He, H. Sodium-promoted Pd/TiO2 for catalytic oxidation of formaldehyde at ambient temperature. Environ. Sci. Technol. 2014, 48 , 5816−5822.
(40) Li, Z.; Chen, Y. J.; Ji, S. F.; Tang, Y.; Chen, W. X.; Li, A.; Zhao, J.; Xiong, Y.; Wu, Y. E.; Gong, Y.; Yao, T.; Liu, W.; Zheng, L. R.; Dong, J. C.; Wang, Y.; Zhuang, Z. B.; Xing, W.; He, C.-T.; Peng, C.; Cheong, W.-C.; Li, Q. H.; Zhang, M. L.; Chen, Z.; Fu, N. H.; Gao, X.; Zhu, W.; Wan, J. W.; Zhang, J.; Gu, L.; Wei, S. Q.; Hu, P. J.; Luo, J.; Li, J.; Chen, C.; Peng, Q.; Duan, X. F.; Huang, Y.; Chen, X.-M.; Wang, D. S.; Li, Y. D. Iridium single-atom catalyst on nitrogen-doped carbon for formic acid oxidation synthesized using a general host− guest strategy. Nat. Chem. 2020, 12 , 764−772.
(41) Chen, C.; Zhu, X. R.; Wen, X. J.; Zhou, Y. Y.; Zhou, L.; Li, H.; Tao, L.; Li, Q.; Du, S.; Liu, T. T.; Yan, D. F.; Xie, C.; Zou, Y. Q.; Wang, Y. Y.; Chen, R.; Huo, J.; Li, Y.; Cheng, J.; Su, H.; Zhao, X.; Cheng, W. R.; Liu, Q. H.; Lin, H. Z.; Luo, J.; Wang, S. Y. Coupling N2 and CO2 in H2O to synthesize urea under ambient conditions. Nat. Chem. 2020, 12 , 717−724.
(42) Zhang, X.; Xiong, W. P.; Wang, T.; Chai, E. C.; Lin, J.; Huang, L. T.; Feng, Y. Y.; Wu, M. X.; Wang, Y. B. Cascade electrosynthesis of LiTFSI and N-containing analogues via a looped Li−N2 battery. Nat. Catal. 2024, 7 , 55.
(43) Espino-Estévez, M. R.; Fernández-Rodríguez, C.; GonzálezDíaz, O. M.; Arana, J.; Espinós, J. P.; Ortega-Méndez, J. A.; DonaRodríguez, J. M. Effect of TiO2−Pd and TiO2−Ag on the photocatalytic oxidation of diclofenac, isoproturon and phenol. Chem. Eng. J. 2016, 298 , 82−95.
(44) Zhang, W.; Pan, G.; Han, D.; Liu, T.; Liang, W.; Han, D.; Dai, M.; Xie, H.; Qin, D.; Niu, L. Regulating bimetallic active centers for − exploring the structure activity relationship toward high-performance photocatalytic nitrogen reduction. Mater. Today Nano 2023, 22 , No. 100323.
(45) Yang, Z. X.; Wang, J. Q.; Wang, J. T.; Li, M.; Cheng, Q.; Wang, Z. Z.; Wang, X. T.; Li, J. M.; Li, Y.; Zhang, G. K. 2D WO3−x nanosheet with rich oxygen vacancies for efficient visible-light-driven photocatalytic nitrogen fixation. Langmuir 2022, 38 (3), 1178−1187.
(46) Zhang, W. S.; Tan, Q. M.; Liu, T. R.; He, Y.; Chen, G.; Chen, K.; Han, D. X.; Qin, D. D.; Niu, L. Fabrication of water-floating litchilike polystyrene-sphere-supported TiO2/Bi2O3 S-scheme heterojunction for efficient photocatalytic degradation of tetracycline. Mater. Horiz. 2023, 10 , 5869−5880.
(47) Xiao, X. D.; Gao, Y. T.; Zhang, L. P.; Zhang, J. C.; Zhang, Q.; Li, Qi; Bao, H. L.; Zhou, J.; Miao, S.; Chen, N.; Wang, J. Q.; Jiang, B. J.; Tian, C. G.; Fu, H. G. A promoted charge separation/transfer system from Cu single atoms and C3N4 layers for efficient photocatalysis. Adv. Mater. 2020, 32 , 2003082.
(48) Liu, X. Q.; Iocozzia, J.; Wang, Y.; Cui, X.; Chen, Y. H.; Zhao, S. Q.; Li, Z.; Lin, Z. Q. Noble metal-metal oxide nanohybrids with tailored nanostructures for efficient solar energy conversion, photocatalysis and environmental remediation. Energy Environ. Sci. 2017, 10 , 402−434.
(49) Li, J. M.; Li, Y.; Wang, X. T.; Yang, Z. X.; Zhang, G. K. Atomically dispersed Fe sites on TiO2 for boosting photocatalytic CO2 reduction: Enhanced catalytic activity, DFT calculations and mechanistic insight. Chine. J. Catal. 2023, 51 , 145−156.
(50) Wang, X. T.; Wang, Z. Z.; Li, Y.; Wang, J. T.; Zhang, G. K. Efficient photocatalytic CO2 conversion over 2D/2D Ni-doped CsPbBr3/Bi3O4Br Z-scheme heterojunction: Critical role of Ni
doping, boosted charge separation and mechanism study. Appl. Catal., B 2022, 319 , No. 121895.
(51) Wang, K.; Du, Y.; Li, Y.; Wu, X. Y.; Hu, H. Y.; Wang, G. H.; Xiao, Y.; Chou, S. L.; Zhang, G. K. Atomic-level insight of sulfidationengineered Aurivillius-related Bi2O2SiO3 nanosheets enabling visible light low-concentration CO2 conversion. Carbon Energy 2023, 5 , No. e264.
(52) Toe, C. Y.; Scott, J.; Amal, R.; Ng, Y. H. Recent advances in suppressing the photocorrosion of cuprous oxide for photocatalytic and photoelectrochemical energy conversion. J. Photoch. Photobio. C 2019, 40 , 191−211.
(53) Liu, Y. P.; Yu, H. B.; Cui, X.; Gong, Y. H.; Lu, Y.; Qin, W. C.; Huo, M. X. Synthesis of N-C3N4/Cu/Cu2O: New strategy to tackle the problem of Cu2O photocorrosion with the help of band engineering. Sepa. Purif. Technol. 2022, 282 , No. 119871.
(54) Zhang, S.; Zhao, Y. X.; Shi, R.; Zhou, C.; Waterhouse, G. I. N.; Wu, L.-Z.; Tung, C.-H.; Zhang, T. R. Efficient photocatalytic nitrogen fixation over Cu [δ][+] -modified defective ZnAl-layered double hydroxide nanosheets. Adv. Energy Mater. 2020, 10 , 1901973.
(55) Zhang, G. Q.; Yang, X.; He, C. X.; Zhang, P. X.; Mi, H. W. Constructing a tunable defect structure in TiO2 for photocatalytic nitrogen fixation. J. Mater. Chem. A 2020, 8 , 334−341.
(56) Wang, S. Y.; Hai, X.; Ding, X.; Chang, K.; Xiang, Y. G.; Meng, X. G.; Yang, Z. X.; Chen, H.; Ye, J. H. Light-switchable oxygen vacancies in ultrafine Bi5O7Br nanotubes for boosting solar-driven nitrogen fixation in pure water. Adv. Mater. 2017, 29 , 1701774.
(57) Zhang, N.; Jalil, A.; Wu, D. X.; Chen, S. M.; Liu, Y. F.; Gao, C.; Ye, W.; Qi, Z. M.; Ju, H. X.; Wang, C. M.; Wu, X. J.; Song, L.; Zhu, J. F.; Xiong, Y. J. Refining defect states in W18O49 by Mo doping: A strategy for tuning N2 activation towards solar-driven nitrogen fixation. J. Am. Chem. Soc. 2018, 140 , 9434−9443.
(58) Huang, P. C.; Liu, W.; He, Z. H.; Xiao, C.; Yao, T.; Zou, Y. M.; Wang, C. M.; Qi, Z. M.; Tong, W.; Pan, B. C.; Wei, S. Q.; Xie, Y. Single atom accelerates ammonia photosynthesis. Sci. China Chem. 2018, 61 , 1187−1196.
(59) Hirakawa, H.; Hashimoto, M.; Shiraishi, Y.; Hirai, T. Photocatalytic conversion of nitrogen to ammonia with water on surface oxygen vacancies of titanium dioxide. J. Am. Chem. Soc. 2017, 139 , 10929−10936.
(60) Dong, G. H.; Ho, W. K.; Wang, C. Y. Selective photocatalytic N2 fixation dependent on g-C3N4 induced by nitrogen vacancies. J. Mater. Chem. A 2015, 3 , 23435−23441.
(61) Kim, M.; Lee, B.; Ju; Lee, S. W.; Kim, J. Reducing the barrier energy of self-reconstruction for anchored Cobalt nanoparticles as highly active oxygen evolution electrocatalyst. Adv. Mater. 2019, 31 , 1901977.
(62) Yuan, W. T.; Zhu, B. E.; Fang, K.; Li, X.-Y.; Hansen, T. W.; Ou, Y.; Yang, H. S.; Wagner, J. B.; Gao, Y.; Wang, Y.; Zhang, Z. In situ manipulation of the active Au-TiO2 interface with atomic precision during CO oxidation. Science 2021, 371 , 517−521.
(63) Yuan, J. L.; Yi, X. Y.; Tang, Y. H.; Liu, M. J.; Liu, C. B. Efficient photocatalytic nitrogen fixation: enhanced polarization, activation, and cleavage by asymmetrical electron donation to N≡N bond. Adv. Funct. Mater. 2020, 30 , 1906983.
(64) Asadi, M.; Kim, K.; Liu, C.; Addepalli, A. V.; Abbasi, P.; Yasaei, P.; Phillips, P.; Behranginia, A.; Cerrato, J. M.; Haasch, R.; Zapol, P.; Kumar, B.; Klie, R. F.; Abiade, J.; Curtiss, L. A.; Salehi-Khojin, A. Nanostructured transition metal dichalcogenide electrocatalysts for CO2 reduction in ionic liquid. Science 2016, 353 , 467−470.
(65) Xia, S. J.; Zhang, G. H.; Gao, Z. Y.; Meng, Y.; Xie, B.; Lu, H. F.; Ni, Z. M. 3D hollow Bi2O3@CoAl-LDHs direct Z-scheme heterostructure for visible-light-driven photocatalytic ammonia synthesis. J. Colloid Interface Sci. 2021, 604 , 798−809.
(66) Zhang, Y. Q.; Ma, N. G.; Wang, T. R.; Fan, J. Work function regulation of surface-engineered Ti2CT2 MXenes for efficient electrochemical nitrogen reduction reaction. Nanoscale 2022, 14 , 12610−12619.
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