Photocatalytic Dry Reforming of Methane Enhanced by “Dual-Path” Strategy with Excellent Low-Temperature Catalytic Performance

Dry reforming of methane (DRM), which involves the activation of inert C H bonds and CO bonds, at mild conditions is a tremendous challenge. The sluggish mobility of oxygen during the reaction is known as a key issue causing low activity and poor stability of catalysts by the coke formation. Herein, a novel Cu-CNN/Pd-BDCNN photocatalyst that is made up of “Cu-nanoparticle-loaded g-C₃N₄ nanosheets” and “Pd-nanoparticle-loaded boron-doped nitrogen-deficient g-C₃N₄ nanosheets” is reported. The existing dual-reaction-sites benefit the reactive oxygen intermediates participate in the reaction directly without distant migration. The in situ characterizations and density functional theory calculations reveal a newly dual reaction pathway through simultaneous dehydrogenation of methoxy and methyl intermediates, and demonstrate the importance of metal loading, which promote the CO₂ and CH₄ activation from both aspects of thermodynamics and kinetics. The optimized Cu-CNN/Pd-BDCNN photocatalyst displays an excellent syngas formation rate of over 800 µmol g⁻¹ h⁻¹ with H₂/CO = 1 and splendid stability in continuous flow reaction under 300 mW cm⁻² xenon lamp irradiation at room temperature. The “dual-site” and “dual-path” strategy shed light on the design of effective photocatalysts for methane dry reforming.     

A Novel Multifunctional Photocatalytic Separation Membrane Based on Single-Component Seaweed-Like g-C3N4

Multifunctional separation membrane is usually realized by multi-component collaborative construction, which makes the membrane preparation method complicated and uncontrollable. Herein, a novel multifunctional photocatalytic separation membrane is prepared by vacuum self-assembly of single seaweed-like g-C₃N₄ photocatalyst. The seaweed-like g-C₃N₄ gives membrane certain roughness, large specific surface area, excellent hydrophilicity and abundant transport channels. Through a systematic study, the membrane exhibits excellent separation of five oil-in-water emulsions with a maximum flux of 3114.0 ± 113.0 L m⁻² h⁻¹ bar⁻¹ for 1, 2-dichloroethane-in-water (Dc/W) emulsion and a maximum efficiency of 97.4 ± 0.1% for chloroform-in-water (C/W) emulsion. In addition, the seaweed-like g-C₃N₄ with large specific surface area and narrow bandgap render excellent visible light absorption characteristics and accelerate e⁻-h⁺ pairs transport rate, giving the membrane excellent photocatalytic degradation and antibacterial properties. The membrane shows good degradation for eight different pollutants, among which the degradation effect for rhodamine B (RhB), methylene blue (MB), and crystal violet (CV) were ≈100%. The antibacterial efficiency against E. coli and S. aureus is also close to 100%. After 35 consecutive separations of C/W emulsion and 10 consecutive degradations of RhB, the membrane still maintains excellent separation performance. This long-lasting multifunctional separation membrane exhibits broad application prospects in complex wastewater purification.     

Single-Atom Catalysts for H2O2 Electrosynthesis via Two-Electron Oxygen Reduction Reaction

Oxygen reduction reaction via the two-electron route (2e⁻ ORR) provides a green method for the direct production of hydrogen peroxide (H₂O₂) along with in situ utilization. The effective catalysts with high ORR activity, 2e⁻ selectivity, and stability are essential for the application of this technology. Single-atom catalysts (SACs) have attracted intensively attention for H₂O₂ electrosynthesis owing to the unique geometric and electronic configurations. In this review, the mechanism and theoretical predictions for 2e⁻ ORR over SACs are first introduced. Then, the recent advances of various SACs for the electrosynthesis of H₂O₂ are documented. And the correlation between the central atom, coordination atoms, and coordination environment of SACs and the corresponding electrocatalytic ORR performance including activity, selectivity, and stability are emphatically analyzed and summarized. Finally, the major challenges and opportunities regarding the future design of SACs for the H₂O₂ production are pointed out.     

Development of novel Ag modified BiOF squares/g-C3N4 composite for photocatalytic applications

A novel Ag modified BiOF/g-C₃N₄ (Ag-BiOF/g-C₃N₄) organic–inorganic hybrid photocatalysts have been synthesized by a facile solvothermal route. The photocatalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflection spectroscopy (UV-DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic studies reveals that the as-prepared Ag-BiOF/g-C₃N₄ photocatalyst exhibited significantly enhanced photocatalytic activity than the pure BiOF and BiOF/g-C₃N₄ photocatalysts toward degrading methylene blue (MB) under visible light irradiation. The heterostructured combination of Ag, g-C₃N₄ and BiOF micro squares provides synergistic photocatalytic performance through an efficient electron transport mechanism.     

Cocatalyst Engineering with Robust Tunable Carbon-Encapsulated Mo-Rich Mo/Mo2C Heterostructure Nanoparticle for Efficient Photocatalytic Hydrogen Evolution

Cocatalyst engineering with non-noble metal nanomaterials can play a vital role in low-cost, sustainable, and large-scale photocatalytic hydrogen production. This research adopts slow carburization and simultaneous hydrocarbon reduction to synthesize carbon-encapsulated Mo/Mo₂C heterostructure nanoparticles, namely Mo/Mo₂C@C cocatalyst. Experimental and theoretical investigations indicate that the Mo/Mo₂C@C cocatalysts have a nearly ideal hydrogen-adsorption free energy (ΔG_H*), which results in the accelerated HER kinetics. As such, the cocatalysts are immobilized onto organic polymer semiconductor g-C₃N₄ and inorganic semiconductor CdS, resulting in Mo/Mo₂C@C/g-C₃N₄ and Mo/Mo₂C@C/CdS catalysts, respectively. In photocatalytic hydrogen evolution application under visible light, the Mo/Mo₂C@C with g-C₃N₄ and CdS can form the Schottky junctions via appropriate band alignment, greatly suppressing the recombination of photoinduced electron-hole pairs. The surface carbon layer as the conducting scaffolds and Mo metal facilitates electron transfer and electron-hole separation, favoring structural stability and offering more reaction sites and interfaces as electron mediators. As a result, these catalysts exhibit high H₂ production rates of 2.7 mmol h⁻¹ g⁻¹ in basic solution and 98.2 mmol h⁻¹ g⁻¹ in acidic solution, respectively, which is significantly higher than that of the bench-mark Pt-containing catalyst. The proposed cocatalyst engineering approach is promising in developing efficient non-noble metal cocatalysts for rapid hydrogen production.     

Synthesis of Leaf‐Vein‐Like g‐C3N4 with Tunable Band Structures and Charge Transfer Properties for Selective Photocatalytic H2O2 Evolution

Photocatalytic H₂O₂ evolution through two‐electron oxygen reduction has attracted wide attention as an environmentally friendly strategy compared with the traditional anthraquinone or electrocatalytic method. Herein, a biomimetic leaf‐vein‐like g‐C₃N₄ as an efficient photocatalyst for H₂O₂ evolution is reported, which owns tenable band structure, optimized charge transfer, and selective two‐electron O₂ reduction. The mechanism for the regulation of band structure and charge transfer is well studied by combining experiments and theoretical calculations. The H₂O₂ yield of CN4 (287 µmol h^?1) is about 3.3 times higher than that of pristine CN (87 µmol h^?1), and the apparent quantum yield for H₂O₂ evolution over CN4 reaches 27.8% at 420 nm, which is much higher than that for many other current photocatalysts. This work not only provides a novel strategy for the design of photocatalyst with excellent H₂O₂ evolution efficiency, but also promotes deep understanding for the role of defect and doping sites on photocatalytic activity.     

Dual-Engineering of Porous Structure and Carbon Edge Enables Highly Selective H2O2 Electrosynthesis

Edge engineering has emerged as a powerful strategy to activate inert carbon surfaces, and thus achieve a notable enhanced electrocatalytic activity. However, the rational manipulation of carbon edges to achieve enhanced catalytic performance remains a formidable challenge, primarily hindered by immature synthesis methods and the obscured understanding of the structure-activity relationship. Herein, an organic–inorganic hybrid co-assembly strategy is used to fabricate a series of mesoporous carbon nanofibers (MCNFs) with controllable edge site densities and the impact of edge population on electrochemical oxygen reduction reaction (ORR) pathways is investigated. The optimized MCNFs catalyst exhibits a remarkable 2e⁻ ORR performance, as evidenced by a high H₂O₂ selectivity (>90%) across a wide potential window of 0.6 V and a large cathodic current density of −3.0 mA cm⁻² (at 0.2 V vs. reversible hydrogen electrode). Strikingly, the density of carbon edge sites can be changed to tune the ORR activity and selectivity. Experimental validation and density functional theory calculations confirm that the presence of edge defects can optimize the adsorption strength of *OOH intermediates and balance the selectivity and activity of the 2e⁻ ORR process. This study provides a new path to achieve high ORR activity and 2e⁻ selectivity in carbon-based electrocatalysts.     

Carbon Black-Supported Single-Atom Co?N?C as an Efficient Oxygen Reduction Electrocatalyst for H2O2 Production in Acidic Media and Microbial Fuel Cell in Neutral Media

Single metal atom isolated in nitrogen-doped carbon materials (M N C) are effective electrocatalysts for oxygen reduction reaction (ORR), which produces H₂O₂ or H₂O via 2-electron or 4-electron process. However, most of M N C catalysts can only present high selectivity for one product, and the selectivity is usually regulated by complicated structure design. Herein, a carbon black-supported Co N C catalyst (CB@Co N C) is synthesized. Tunable 2-electron/4-electron behavior is realized on CB@Co-N-C by utilizing its H₂O₂ yield dependence on electrolyte pH and catalyst loading. In acidic media with low catalyst loading, CB@Co N C presents excellent mass activity and high selectivity for H₂O₂ production. In flow cell with gas diffusion electrode, a H₂O₂ production rate of 5.04 mol h⁻¹ g⁻¹ is achieved by CB@Co N C on electrolyte circulation mode, and a long-term H₂O₂ production of 200 h is demonstrated on electrolyte non-circulation mode. Meanwhile, CB@Co N C exhibits a dominant 4-electron ORR pathway with high activity and durability in pH neutral media with high catalyst loading. The microbial fuel cell using CB@Co N C as the cathode catalyst shows a peak power density close to that of benchmark Pt/C catalyst.     

Regulating the Metallic Cu–Ga Bond by S Vacancy for Improved Photocatalytic CO2 Reduction to C2H4

Artificial photosynthesis, which converts carbon dioxide into hydrocarbon fuels, is a promising strategy to overcome both global warming and energy crisis. Herein, the geometric position of Cu and Ga on ultra-thin CuGaS₂/Ga₂S₃ is oriented via a sulfur defect engineering, and the unprecedented C₂H₄ yield selectivity is ≈93.87% and yield is ≈335.67 µmol g⁻¹ h⁻¹. A highly delocalized electron distribution intensity induced by S vacancy indicates that Cu and Ga adjacent to S vacancy form Cu–Ga metallic bond, which accelerates the photocatalytic reduction of CO₂ to C₂H₄. The stability of the crucial intermediates (*CHOHCO) is attributed to the upshift of the d-band center of ultra-thin CGS/GS. The C–C coupling barrier is intrinsically reduced by the dominant exposed Cu atoms on the 2D ultra-thin CuGaS₂/Ga₂S₃ in the process of photocatalytic CO₂ reduction, which captures *CO molecules effectively. This study proposes a new strategy to design photocatalyst through defect engineering to adjust the selectivity of photocatalytic CO₂ reduction.     

Generalized Synthetic Strategy for Amorphous Transition Metal Oxides-Based 2D Heterojunctions with Superb Photocatalytic Hydrogen and Oxygen Evolution

2D amorphous transition metal oxides (a-TMOs) heterojunctions that have the synergistic effects of interface (efficiently promoting the separation of electron−hole pairs) and amorphous nature (abundant defects and dangling bonds) have attracted substantial interest as compelling photocatalysts for solar energy conversion. Strategies to facilely construct a-TMOs-based 2D/2D heterojunctions is still a big challenge due to the difficulty of preparing individual amorphous counterparts. A generalized synthesis strategy based on supramolecular self-assembly for bottom–up growth of a-TMOs-based 2D heterojunctions is reported, by taking 2D/2D g-C₃N₄ (CN)/a-TMOs heterojunction as a proof-of-concept. This strategy primarily depends on controlling the cooperation of the growth of supramolecular precursor and the coordinated covalent bonds arising from the tendency of metal ions to attain the stable configuration of electrons, which is independent on the intrinsic character of individual metal ion, indicating it is universally applicable. As a demonstration, the structure, physical properties, and photocatalytic water-splitting performance of CN/a-ZnO heterojunction are systematically studied. The optimized 2D/2D CN/a-ZnO exhibits enhanced photocatalytic performance, the hydrogen (432.6 µmol h⁻¹ g⁻¹) and oxygen (532.4 µmol h⁻¹ g⁻¹) evolution rate are 15.5 and 12.2 times than bulk CN, respectively. This synthetic strategy is useful to construct 2D a-TMOs nanomaterials for applications in energy-related areas and beyond.     

Enhanced photo-induced charge separation and solar-driven photocatalytic activity of g-C3N4 decorated by SO42−

SO₄²⁻ decorated g-C₃N₄ with enhanced photocatalytic performance was prepared by a facile pore impregnating method using (NH₄)₂S₂O₈ solution. The photocatalysts were characterized by the Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and surface photovoltage (SPV) spectroscopy, respectively. The separation efficiency of photo-generated charge was investigated using benzoquinone as scavenger. The results demonstrate that sulfating of g-C₃N₄ increases the adsorption of rhodamine B on g-C₃N₄, the hydroxyl content and the separation efficiency of photo-generated charge. The photocatalytic activity of SO₄²⁻/g-C₃N₄ for decolorization of rhodamine B and methyl orange (MO) aqueous solution was evaluated. The result shows that loading of 6.0 wt% SO₄²⁻ results in the best photocatalytic activity under simulated solar irradiation and SO₄²⁻ play an important role in boosting the photocatalytic activity.     

Engineering the Photocatalytic Behaviors of g/C3N4‐Based Metal‐Free Materials for Degradation of a Representative Antibiotic

Graphitic carbon nitride (g/C₃N₄) is of promise as a highly efficient metal‐free photocatalyst, yet engineering the photocatalytic behaviours for efficiently and selectively degrading complicated molecules is still challenging. Herein, the photocatalytic behaviors of g/C₃N₄ are modified by tuning the energy band, optimizing the charge extraction, and decorating the cocatalyst. The combination shows a synergistic effect for boosting the photocatalytic degradation of a representative antibiotic, lincomycin, both in the degradation rate and the degree of decomposition. In comparison with the intrinsic g/C₃N₄, the structurally optimized photocatalyst shows a tenfold enhancement in degradation rate. Interestingly, various methods and experiments demonstrate the specific catalytic mechanisms for the multiple systems of g/C₃N₄‐based photocatalysts. In the degradation, the active species, including ·O₂^?, ·OH, and h⁺, have different contributions in the different photocatalysts. The intermediate, H₂O₂, plays an important role in the photocatalytic process, and the detailed functions and originations are clarified for the first time.     

Covalent Furan-Benzimidazole-Linked Polymer Hollow Fiber Membrane for Clean and Efficient Photosynthesis of Hydrogen Peroxide

Photocatalytic H₂O₂ production by conversion of O₂ in aqueous solution is often challenged by the use of sacrificial agents, the separation of powdery photocatalysts, solution, and contaminants, and low activity of photocatalyst. Herein, a membrane of covalent furan-benzimidazole-linked polymer (Furan-BILP) with both O- and N-containing heterocycles bonded via O C CN is reported for the first time as a photocatalyst to harvest clean H₂O₂ in pure water with high-performance. A coordination-polymer hard template strategy is developed to produce Furan-BILP hollow microfibers that can be further assembled into membranes with desired sizes. The resultant Furan-BILP membrane directly delivers clean H₂O₂ solution as the product with a high H₂O₂ production rate of 2200 µmol g⁻¹ h⁻¹ in pure water. Density functional theory calculations and experiment results indicate that the C atom from Furan ring on the linkage binds to the adsorbed OOH^*, the H atom of OOH^* forms a hydrogen bond with the N atom in the benzimidazole ring, thus the intermediate six-membered ring structure stabilizes the OOH^* and favors 2e-ORR. The strategy using both molecular engineering to tune the electronic structure and macrostructural engineering to shape the morphology may be applied to design other coordination organic polymer photocatalysts with further improved performance.     

Atomistic Structural Engineering of Conjugated Microporous Polymers Promotes Photocatalytic Biomass Valorization

Polymer photocatalysts have great promise for solar fuel production due to their flexible structural and functional designability. However, their photocatalytic efficiencies are still unsatisfactory, limited by their intrinsically large exciton binding energy and fast charge recombination. Herein, the atomistic structural engineering of donor–acceptor (D−A) polymer photocatalysts for enhanced charge separation and photocatalytic hydrogen production is proposed. By changing the electron affinity of the acceptor units, the electron delocalization and exciton binding energy of the polymeric networks can be readily tuned, resulting in enhanced charge separation efficiency and photocatalytic activity. The optimal sample shows the highest H₂ production rate of 3207 µmol g⁻¹ h⁻¹ in the presence of ascorbic acid as the sacrificial agent. Moreover, the photocatalytic H₂ production can be coupled with almost stoichiometrical conversion of 5-hydroxymethyl furfural to 2,5-diformylfuran.     

Ice‐Assisted Synthesis of Black Phosphorus Nanosheets as a Metal‐Free Photocatalyst: 2D/2D Heterostructure for Broadband H2 Evolution

A 2D/2D heterojunction of black phosphorous (BP)/graphitic carbon nitride (g‐C₃N₄) is designed and synthesized for photocatalytic H₂ evolution. The ice‐assisted exfoliation method developed herein for preparing BP nanosheets from bulk BP, leads to high yield of few‐layer BP nanosheets (≈6 layers on average) with large lateral size at reduced duration and power for liquid exfoliation. The combination of BP with g‐C₃N₄ protects BP from oxidation and contributes to enhanced activity both under λ > 420 nm and λ > 475 nm light irradiation and to long‐term stability. The H₂ production rate of BP/g‐C₃N₄ (384.17 µmol g^?1 h^?1) is comparable to, and even surpasses that of the previously reported, precious metal‐loaded photocatalyst under λ > 420 nm light. The efficient charge transfer between BP and g‐C₃N₄ (likely due to formed N? P bonds) and broadened photon absorption (supported both experimentally and theoretically) contribute to the excellent photocatalytic performance. The possible mechanisms of H₂ evolution under various forms of light irradiation is unveiled. This work presents a novel, facile method to prepare 2D nanomaterials and provides a successful paradigm for the design of metal‐free photocatalysts with improved charge‐carrier dynamics for renewable energy conversion.     

In Situ Topochemical Transformation of ZnIn2S4 for Efficient Photocatalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Diformylfuran

Photocatalytic selective oxidation of 5-hydroxymethylfurfural (HMF) coupled H₂ production offers a promising approach to producing valuable chemicals. Herein, an efficient in situ topological transformation tactic is developed for producing porous O-doped ZnIn₂S₄ nanosheets for HMF oxidation cooperative with H₂ evolution. Aberration-corrected high-angle annular dark-field scanning TEM images show that the hierarchical porous O-ZIS-120 possesses abundant atomic scale edge steps and lattice defects, which is beneficial for electron accumulation and molecule adsorption. The optimal catalyst (O-ZIS-120) exhibits remarkable performance with 2,5-diformylfuran (DFF) yields of 1624 µmol h⁻¹ g⁻¹ and the selectivity of >97%, simultaneously with the H₂ evolution rate of 1522 µmol h⁻¹ g⁻¹. Mechanistic investigations through theoretical calculations show that O in the O-ZIS-120 lattice can reduce the oxidation energy barrier of hydroxyl groups of HMF. In situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) results reveal that DFF^* (C₄H₂(CHO)₂O^*) intermediate has a weak interaction with O-ZIS-120 and desorb as the final product. This study elucidates the topotactic structural transitions of 2D materials simultaneously with electronic structure modulation for efficient photocatalytic DFF production.     

Simultaneous CO2 and H2O Activation via Integrated Cu Single Atom and N Vacancy Dual-Site for Enhanced CO Photo-Production

Photocatalytic conversion of CO₂ into fuels using pure water as the proton source is of immense potential in simultaneously addressing the climate-change crisis and realizing a carbon-neutral economy. Single-atom photocatalysts with tunable local atomic configurations and unique electronic properties have exhibited outstanding catalytic performance in the past decade. However, given their single-site features they are usually only amenable to activations involving single molecules. For CO₂ photoreduction entailing complex activation and dissociation process, designing multiple active sites on a photocatalyst for both CO₂ reduction and H₂O dissociation simultaneously is still a daunting challenge. Herein, it is precisely construct Cu single-atom centers and two-coordinated N vacancies as dual active sites on CN (Cu₁/N_2CV-CN). Experimental and theoretical results show that Cu single-atom centers promote CO₂ chemisorption and activation via accumulating photogenerated electrons, and the N_2CV sites enhance the dissociation of H₂O, thereby facilitating the conversion from COO* to COOH*. Benefiting from the dual-functional sites, the Cu₁/N_2CV-CN exhibits a high selectivity (98.50%) and decent CO production rate of 11.12 µmol g⁻¹ h⁻¹. An ingenious atomic-level design provides a platform for precisely integrating the modified catalyst with the deterministic identification of the electronic property during CO₂ photoreduction process.     

Mo-Modified ZnIn2S4@NiTiO3 S-Scheme Heterojunction with Enhanced Interfacial Electric Field for Efficient Visible-Light-Driven Hydrogen Evolution

Designing and developing visible-light-responsive materials for solar to chemical energy is an efficient and promising approach to green and sustainable carbon-neutral energy systems. Herein, a facile in situ growth hydrothermal strategy using Mo-modified ZnIn₂S₄ (Mo-ZIS) nanosheets coupled with NiTiO₃ (NTO) microrods to synthesize multifunctional Mo-modified ZIS wrapped NTO microrods (Mo-ZIS@NTO) photocatalyst with enhanced interfacial electric field (IEF) effect and typical S-scheme heterojunction is reported. Mo-ZIS@NTO catalyst possesses wide-spectrum light absorption properties, excellent visible light-to-thermal energy effect, electron mobility, charges transfer, and strong IEF and exhibits excellent solar-to-chemical energy conversion for efficient visible-light-driven photocatalytic hydrogen evolution. Notably, the engineered Mo_1.4-ZIS@NTO catalyst exhibits superior performance with H₂ evolution rate of up to 14.06 mmol g⁻¹ h^{− 1} and the apparent quantum efficiency of 44.1% at 420 nm. The scientific explorations provide an in-depth understanding of microstructure, S-scheme heterojunction, enhanced IEF, Mo-dopant facilitation effect. Moreover, the theoretical simulations verify the critical role of Mo element in promoting the adsorption and activation of H₂O molecules, modulating the H adsorption behavior on active S sites, and thus accelerating the overall catalytic efficiency. The photocatalytic hydrogen evolution mechanism via S-scheme heterojunction with adjustable IEF regulation over Mo_1.4-ZIS@NTO is also demonstrated.     

Pre-Adsorbed H-Assisted N2 Activation on Single-Atom Cadmium-O5 Decorated In2O3 for Efficient NH3 Electrosynthesis

The electrocatalytic nitrogen reduction reaction (NRR) provides a promising avenue for sustainable and decentralized green ammonia (NH₃) synthesis. To promote the NRR, the design and synthesis of efficient electrocatalysts with an elucidated reaction mechanism is critically important. Here, surface hydrogenation-facilitated NRR is demonstrated to yield NH₃ at low overpotentials on oxygen-deficient In₂O₃ plates decorated with single atom CdO₅ that have a weak N₂-binding capability. Adsorbed ^*H is calculated to be first produced via the Volmer reaction (H₂O + e⁻ → ^*H + OH⁻) and then reacts with dissolved N₂ to generate ^*N₂H₂, which is likely the rate determining step (RDS) of the whole process. Cd atoms and oxygen vacancies in In₂O₃ jointly enhance the activation of N₂ and accelerate the RDS, boosting the NRR. An NH₃ production rate of as high as 57.5 µg h⁻¹ mg_cat⁻¹ is attained at a mild potential, which is retained to a large extent even after 44 h of continuous polarization.     

Nanocellulose-Assisted Molecularly Engineering of Nitrogen Deficient Graphitic Carbon Nitride for Selective Biomass Photo-Oxidation

Structural modulation of graphitic carbon nitride (g-C₃N₄) remains a major challenge in rational catalyst design for artificial photosynthesis of valuable chemicals. Herein, a cellulose nanofiber (CNF) assisted polymerization is utilized to prepare 1D holey g-C₃N₄ nanorods (HCN) with nitrogen vacancies and oxygen dopants for photochemical synthesis of lactic acid via monosaccharide photooxidation. The HCN exhibits a remarkable yield of 75.5% for lactic acid from a wide assortment of sugars such as hexose (C5) to pentose (C6), together with an excellent hydrogen production rate of 2.8 mmol h⁻¹ g⁻¹. Mechanistic studies confirm the rapid generation of superoxide radical is responsible for the superior activity, enjoying the synergetic effect between nitrogen vacancies and oxygen dopants. This work provides new directions for the design of green and efficient photocatalysts for biomass upgrading.