SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3610-7
Electrochemical CO2 reduction reaction (CO2RR) offers an attractive route to produce value-added multicarbon (C2+) products, yet suffers from competing hydrogen evolution and monocarbon production. Here, we propose a dual-confinement effect on CO2 reactant and *CO intermediate, induced by tuning the pore configuration of reconstructed covalent organic frameworks (RC-COFs). The highly crystalline microporous RC-COF-1, when coated on a Cu electrode, enhances local CO2 concentration and restricts CO diffusion, thereby promoting C-C coupling. In acidic electrolyte, the RC-COF-1@Cu electrode achieves a maximum C2+ Faradaic efficiency (FE) of 67.0% at 500 mA cm−2, while maintaining a total carbon product FE above 90% across a broad current density range (100–500 mA cm−2). Experimental and theoretical analyses confirm that the ordered micropores of RC-COF-1 modulate reactant adsorption and intermediate diffusion, leading to improved C2+ selectivity. This work underscores the critical role of COF pore architecture in microenvironment engineering for heterogeneous catalysis.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3892-2
Single-atom co-catalysts on semiconductor substrates offer a cost-efficient route to enhance photocatalytic performance with minimal precious metal loading. However, precise tuning of local coordination environments and construction of efficient single-atom co-catalysts remain challenging for overall water splitting. Here, we employ an icing-assisted photochemical reduction strategy to anchor atomically dispersed Pt species as hydrogen evolution co-catalysts on Al3+-doped SrTiO3 (Pt SA-STO). The optimized Pt SA-STO exhibits remarkable activity, with hydrogen and oxygen evolution rates of 13.62 and 6.71 mmol h−1 g−1, respectively, and a turnover frequency (TOF) of 2114.5 h−1. We pioneer the use of nuclear magnetic resonance (NMR) spectroscopy to quantitatively track the temporal evolution of Pt4+ to Pt2+ under continuous irradiation during the icing-assisted photoreduction. Advanced characterizations and theoretical calculations confirm that single-atom Pt co-catalysts facilitate directional transfer and extraction of photogenerated charge carriers, effectively suppressing surface recombination. This work provides insights into designing novel single-atom co-catalysts by deepening understanding of electronic configurations and active sites in photocatalytic overall water splitting.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3331-0
Hollow nanostructures with highly accessible surfaces and short charge-transport distances are pivotal for photo(electro)chemical reactions. Perovskite-type SrTiO3 (STO) is a promising photocatalyst for solar water splitting, yet the synthesis of uniform hollow single crystals with well-defined shells remains challenging due to the cubic symmetry and thermodynamic instability of curved surfaces. Here, we report the controllable synthesis of single-crystal STO hollow spheres with ultrathin shells (UTSS-STO) via a simple etching method. Selective etching of low-crystallinity interiors within mesoporous STO single crystals (MS-STO) yields hollow spherical shells and 2D sheet-like single crystals. The resulting UTSS-STO exhibits a 2.5-fold enhancement in photocatalytic hydrogen evolution compared to MS-STO. This improvement is attributed to the ultrathin porous shell, which shortens charge transport lengths and provides abundant active sites, as well as interlayer stress and an optimized electronic band structure that facilitate charge separation. HAADF-STEM and EDS mapping confirm uniform distribution of Rh/Cr2O3 cocatalysts on both inner and outer surfaces of the shell. This work demonstrates the advantage of hollow spherical shells for STO photocatalysts and offers insights into the fabrication of uniform hollow single crystals for efficient solar energy conversion.
SCIENCE CHINA Materials•2025•DOI: 10.1007/s40843-025-3571-y
Two-dimensional (2D) BiOBr has attracted considerable attention for optoelectronic applications, yet reported 2D BiOBr predominantly exhibits n-type conductivity. The absence of high-quality p-type 2D BiOBr impedes the development of complementary metal oxide semiconductor (CMOS) integrated circuits. This study reports the synthesis of large-scale, high-quality p-type 2D BiOBr single crystals via chemical potential modulation chemical vapor deposition (CPMCVD). By precisely modulating the oxygen chemical potential during growth, the conduction polarity of 2D BiOBr is controllably switched between p-type and n-type. Density functional theory calculations reveal that high oxygen chemical potential promotes bismuth vacancy formation, yielding p-type conductivity, whereas low oxygen chemical potential favors oxygen vacancies, resulting in n-type BiOBr. Field-effect transistors (FETs) fabricated from the p-type crystals exhibit a hole mobility of 26.28 cm2 V−1 s−1 and an on/off ratio exceeding 10^4. The n-type FETs demonstrate an electron mobility of 59.59 cm2 V−1 s−1, surpassing most reported n-type 2D FETs. This CPMCVD approach enables precise polarity control without extrinsic doping, offering a scalable route for integrating 2D BiOBr into CMOS technology.