Positioning water within 3.07 Å of C₆₀ to trigger hydrogen photo-evolution

The photocatalysts have been well explored due to their eco-friendly nature. The distance between water and catalyst is crucial for water splitting. However, the distance between water and catalyst active sites for hydrogen evolution has not yet been investigated due to identification challenges. Fullerene C₆₀ has a highly symmetric structure, allowing the distance between water and active site to be identified. Herein, water-C₆₀ distance was tuned from 3.55/3.56 Å to 3.07 Å to trigger hydrogen photo-evolution. The C₆₀@(H₂O)₆₀ were created by bringing water to within approximately 3.07 Å of C₆₀ using a simple sonication method. The structure was determined by atomic pair distribution function analysis and density functional theory to be a highly symmetric core-shell structure with conduction band minimum of −4.27 eV and valence band maximum of −5.82 eV to favor hydrogen photo-evolution. An excellent hydrogen evolution rate of 5.7 mmol h⁻¹ g⁻¹ was obtained from C₆₀@(H₂O)₆₀. Only the water in C₆₀@(H₂O)₆₀ was found to be involved in hydrogen production from its hydrogen production yield. The fullerene has for the first time been demonstrated to be efficient to obtain hydrogen just by manipulating the water-C₆₀ distance under irradiation. This work provides another side to understand the effectiveness of hydrogen photo-evolution.