Pd single atoms cooperate with S vacancies in ZnIn 2 S 4 nanosheets for photocatalytic pure-water splitting

Photocatalytic water splitting has emerged as a new frontier for converting solar energy to green H 2 and value-added chemicals. Nevertheless, great challenges still remain for developing efficient photocatalysts for pure water splitting without sacrificial agents. In this work, we demonstrate that doping hexagonal ZnIn 2 S 4 (ZIS) with Pd single atoms (Pd 0.03 /ZIS) can serve as a highly efficient photocatalyst for pure water splitting to simultaneously produce H 2 and H 2 O 2 without any sacrificial agents. Results from aberration-corrected high-angle annular dark field scanning transmission electron microscopy, X-ray fine spectroscopy, in-situ electron paramagnetic resonance and diffuse Fourier transform infrared spectroscopy reveal that doping ZIS with Pd single atoms facilitates the formation of S vacancies (S v ), where the photogenerated electrons can transfer to Pd single atoms, as a result of enhanced separation of electron-hole pairs and improved photocatalytic performance. Impressively, Pd 0.03 /ZIS displays a stoichiometric ratio of H 2 and H 2 O 2 with the productivity of 1,037.9 and 1,021.4 μmol g −1 h −1 , respectively, which has largely outperformed pure ZIS and other reported catalysts for pure water splitting. This work provides an efficient photocatalyst for water splitting to produce H 2 and H 2 O 2 , which may attract rapid interest in materials science, chemistry, and heterogeneous catalysis.