Intercalation- and Vacancy-Enhanced Internal Electric Fields in ZnIn<sub>2</sub>S<sub>4</sub> for Highly Efficient Photocatalytic H<sub>2</sub>O<sub>2</sub> Production
Chong Ouyang, Xinyao Quan, Zi Ang Chen, Kehan Wang, Xiuquan Gu, Zhanglian Hong, Mingjia Zhi
Abstract
Defect engineering and intercalation modification are feasible strategies to enhance the internal electric field (IEF), which is an effective way for steering photogenerated charge kinetics. Herein, ethylene glycol (EG) and Zn vacancy (V Zn ) are successfully introduced into the intra- and interlayers of ZnIn 2 S 4, respectively, based on the two-dimensional layered structure characteristic of ZnIn 2 S 4 and the special coordination effect between ethylene glycol and Zn 2+ . Comprehensive experimental analysis and theoretical calculations demonstrate that the synergistic effect of EG intercalation and V Zn not only increases the dipole moment inside the unit cell resulting in the enhancement of IEF but also facilitates the kinetics of the 2e – oxygen reduction reaction. Consequently, ZnIn 2 S 4 modified by EG intercalation and V Zn achieves the desired photocatalytic H 2 O 2 production capability (1145.6 μmol/g/h), which is about 4 times that of pristine ZnIn 2 S 4 (294.4 μmol/g/h). This work provides a reference for enhancing the IEF of ZnIn 2 S 4 through intercalation strategies and defect engineering to improve its photocatalytic performance.