Optimization of d-p band centers as efficient active sites for solar energy conversion into H2 by tuning surface atomic arrangement

The lowered reaction energy barrier and accelerated dynamic behavior for photocatalytic H2O overall splitting (HOS) involving oriented chemisorption, activation and conversion of *H and oxyhydrogen intermediates are crucial for solar energy conversion into H-2 (STH). Herein, the localized heterojunction (Cd-S-Ni) composed of NiS and CdS via. tuning surface atomic arrangement with S atoms as the shared ligands has been constructed to synchronously elevate and optimize Ni 3d (Ni epsilon(3d)) and S 2p (S epsilon(2p)) band centers as efficient active sites for chemisorption of oxyhydrogen and *H intermediates with a declined Cd 4d band center (Cd epsilon(4d)) to suppress reverse reaction. A sustainable STH of 3.21 % under AM 1.5 G has been completed over Cd-S-Ni with a decreased activation energy for H-2 evolution, verified by fs-TAS, in situ DRIFTS and dynamic DFT. These results devote to solving the reaction energy barrier and dynamical bottleneck for HOS by optimizing epsilon(d) and epsilon(p).