Highly Asymmetric CuSA‐Ov‐Ti3c Atomic Sites Catalyst for Unprecedented Solar Hydrogen Generation

Abstract

AbstractAtomic‐level tailoring of active sites is an efficient strategy for designing high‐performance photocatalysts for clean energy. Asymmetric atomic sites (AAS) like MSA‐Ov‐M2 created through hetero‐metal single atoms (MSA) doping on defect‐rich metal oxides (M2‐Ov‐M2) are favored for better activation of targeted molecules. However, creating AAS typically demands high energy input, hindering their widespread use in photocatalytic H2 production. Furthermore, precise control over surface defects to create AAS remains challenging. Here, CuSA‐Ov‐Ti3c highly asymmetric atomic sites catalyst (HAASC) is constructed by strategically trapping Cu single atoms on high‐index (111) faceted TiO2. This material combines single‐atom catalysis and facet engineering, achieving unprecedented H2 production rates (8.3 mmol h−1 g−1 in pure water and 784.5 mmol h−1 g−1 in water/methanol mixture). Experimental and theoretical analyses reveal CuSA substituting five‐coordinated Ti atoms (Ti5c) next to three‐coordinated (Ti3c) ones, forming CuSA‐Ov‐Ti3c HAAS. HAAS plays multiple roles in i) improving light harvesting, charge‐transfer dynamics, and redox capability of photoexcited electrons; ii) enhanced adsorption and polarization of H2O molecules; iii) facilitating electron transfer from CuSA‐Ov‐Ti3c to H2O molecules, and iv) raising d‐band center toward Fermi level resulting in ≈250‐fold enhanced H2 production than Ti5c‐O‐Ti3c AASC. This work opens new avenues for future structural designs in heterogeneous catalysis for energy‐related applications.