Free‐Electron Inversive Modulation to Charge Antibonding Orbital of ReS<sub>2</sub> Cocatalyst for Efficient Photocatalytic Hydrogen Generation
Duoduo Gao, Wei Zhong, Xidong Zhang, Ping Wang, Huogen Yu
Abstract
Abstract The free electron transfer between cocatalyst and photocatalyst has a great effect on the bonding strength between the active site and adsorbed hydrogen atom (H ads ), but there is still a lack of effective means to purposely manipulate the electron transfer in a beneficial direction of H adsorption/desorption activity. Herein, when ReS x cocatalyst is loaded on TiO 2 surface, a spontaneous free‐electron transfer from ReS x to TiO 2 happens due to the smaller work function of ReS x , causing an over‐strong S‐H ads bond. To prevent the over‐strong S‐H ads bonds of ReS x in the ReS x /TiO 2 , a free‐electron reversal transfer strategy is developed to weaken the strong S‐H ads bonds via increasing the work function of ReS x by incorporating O to produce ReOS x cocatalyst. Research results attest that a larger work function of ReOS x than that of TiO 2 can induce reversal transfer of electrons from TiO 2 to ReOS x to produce electron‐rich S (2+δ)− , causing the increased antibonding‐orbital occupancy of S‐H ads in ReOS x /TiO 2 . Accordingly, the stability of adsorbed H on S sites is availably decreased, thus weakening the S‐H ads of ReOS x . In this case, an electron‐rich S (2+δ)− ‐mediated “capture‐hybridization‐conversion” mechanism is raised . Benefiting from such property, the resultant ReOS x /TiO 2 photocatalyst exhibits a superior H 2 ‐evolution rate of 7168 µmol h −1 g −1 .