Jinbo Xue

Photocatalytic CO2 hydrogenation to methanol offers a sustainable pathway for carbon resource recycling and low-carbon fuel production, yet the insufficient methanol selectivity, sluggish multi-electron reduction kinetics, and ambiguous structure-activity relationship severely restrict practical development. Copper-based catalysts are uniquely suitable for methanol-oriented CO2 photoreduction, but the distinct roles of multivalent Cu species (Cu0, Cu+, and Cu2+) remain poorly understood. In this work, nitrogen-rich porous carbon spheres derived from potassium acetate activation were adopted as high-conductivity and defect-enriched supports to fabricate a series of Cu-based photocatalysts with precisely regulated valence distribution and controllable metal loading via impregnation and controlled thermal treatment. Comprehensive characterizations and photoelectrochemical tests confirm that the Cu+-dominated catalyst exhibits optimized interfacial coupling, strengthened metal-support interaction, and promoted photogenerated charge separation efficiency. Profiting from the synergistic coupling between anchored Cu+ centers and intrinsic nitrogen active sites within the porous carbon framework, the optimized catalyst achieves a prominent methanol yield of 49.90 μmol·g-1·h-1, along with excellent liquid-product selectivity and long-term cycling stability. In-depth mechanistic analysis reveals that the robust electronic interaction of Cu+-N moieties effectively promotes CO2 adsorption and inert C=O bond activation, accelerates interfacial charge transfer, and preferentially stabilizes the key CH3O* intermediate. Such favorable modulation substantially facilitates the multi-electron hydrogenation pathway toward methanol, while Cu0 and Cu2+ sites are less favorable for stabilizing critical intermediates and readily induce competitive side reactions. This study offers a rational strategy for construction of high-selectivity and high-efficiency non-noble metal photocatalysts toward CO2 green conversion.

Photocatalytic CO ₂ reduction offers a sustainable route to value‐added chemicals, yet conventional systems suffer from limited efficiency and hydrocarbon selectivity due to the spatial mismatch between CO ₂ adsorption and proton sources, delaying proton‐coupled electron transfer (PCET). Here, we construct a Ni/(Sr,Ca)(Ti,Ni)O ₃ heterostructure (Ni/SCTNO) via molten salt exsolution and aluminothermic reduction. Ca ²⁺ doping introduces lattice strain, which drives the in situ exsolution of Ni nanoparticles on the (100) facet, while oxygen vacancies create a positive space charge layer. These effects synergistically form Schottky junctions that act as hydrogen spillover centers, enabling directional H* migration to CO ₂ sites and spatiotemporally coordinating proton–electron transport. Under simulated sunlight, CH ₄ , C ₂ H ₄ , and C ₂ H ₆ yields reach 41.89, 18.01, and 16.53 µmol·g ^{− 1} ·h ^{− 1} , respectively, with a total hydrocarbon selectivity of 55.03%, surpassing most reported perovskite‐based photocatalysts. This work presents an integrated strategy combining heterointerface engineering, strain regulation, and surface modification for efficient CO ₂ ‐to‐multicarbon fuel conversion.

The development of efficient, stable, and cost-effective metal-free photocatalysts is highly urgent for practical CO2 photoreduction, yet conventional photocatalysts typically suffer from insufficient active sites, poor mass transfer, and rapid charge recombination. Herein, self-nitrogen-functionalized hierarchical porous carbon spheres (PACs) were rationally synthesized via one-step suspension polymerization followed by mild potassium salt-assisted activation, using acrylonitrile as the sole carbon and nitrogen precursor. The pore structure engineering strategy effectively optimized the spatial distribution and accessibility of nitrogen-doped sites, enabling the synergistic integration of hierarchical porosity, large specific surface area, and high nitrogen content within a single carbon framework. As a result, the PACs prepared at 700°C with potassium acetate activation exhibited outstanding photocatalytic CO2-to-CO conversion activity and exceptional cycling durability. The CO yield reached 18.74 μmol g-1, remarkably higher than the pristine counterpart (10.63 μmol g-1), and 96.74% of the initial activity was preserved even after 20 consecutive cycles. Systematic characterizations revealed that the hierarchical porous architecture not only exposed abundant accessible nitrogen active sites but also strengthened CO2 adsorption and diffusion kinetics. Meanwhile, surface nitrogen species promoted interfacial charge separation and suppressed photogenerated electron-hole recombination. The synergistic effect between engineered porous structure and tunable nitrogen doping verified the crucial role of bidirectional “pore-nitrogen” regulation in boosting photocatalytic performance. This work provides a facile and mild activation route for constructing high-performance nitrogen-doped carbon-based metal-free photocatalysts, offering a promising paradigm for efficient and stable CO2 photoreduction.

Iron-based oxides are promising bifunctional electrocatalysts. The energy conversion efficiency for water splitting is limited by scarce active sites and sluggish surface reaction in Fe₂O₃. Therefore, we prepared one-dimensional Fe₂O₃ nanobelts arrays (HNBs-V_O(LRO)-S) with ordered oxygen vacancy structure by Pd-catalyzed oxygen reduction and sulfide thermal treatment. While preserving the ordered oxygen vacancy structure, making S atoms selectively fill the trap state oxygen vacancies to improve the bifunctional electrocatalytic activity and stability of Fe₂O₃. Fe₂O₃ nanobelts arrays with synergistic interaction of S-atoms and ordered oxygen vacancies have low overpotentials for anodic oxygen evolution reaction (OER) and cathodic hydrogen evolution reaction (HER). Under the condition of 1 M KOH, the HNBs-V_O(LRO)-S exhibits extraordinary electrocatalytic performances for both HER (226 mV@100 mA cm^-2) and OER (262 mV@10 mA cm^-2，306 mV@100 mA cm^-2). In addition, HNBs-V_O(LRO)-S bifunctional catalyst only requires the low cell voltages of 1.92 V to deliver the current density of 100 mA cm^-2 and exhibits excellent long-term durability over 100 h. The long-range ordered oxygen vacancies serve both as a fast channel for electron transfer and as an active site for the catalytic reaction. The S atoms only fill the trap-state oxygen vacancies (TS-V_O) in the Fe₂O₃ nanobelts, which eliminates the negative effect of TS-V_O in reaction. Meanwhile, formed Fe-S coordination structure both stabilizes the ordered oxygen vacancy structure of HNBs-V_O(LRO)-S and provides more reactive active sites for the electrocatalytic reaction. Theoretical calculations show that the S atoms filling lowers the free energy barrier that the formation of OOH^* from O*, optimizes the ∆G_H* of Fe₂O₃ surface. This ingenious synergistic mechanism of vacancies filling provides new insights into the defective design of catalysts.