Intercalation- and Vacancy-Enhanced Internal Electric Fields in ZnIn₂S₄ for Highly Efficient Photocatalytic H₂O₂ Production

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.

Construction of a 1D/2D S-Scheme Heterojunction of Mo-Doped WO3/In-Doped Carbon Nitride for Efficient Hydrogen Peroxide Photosynthesis

“…Among these photocatalysts, CN has attracted much attention due to its high 2e – ORR selectivity, easy synthesis, low cost, suitable band structure, as well as excellent chemical stability. , However, the photocatalytic activity of CN to produce H 2 O 2 is low due to its limited light absorption and poor charge separation efficiency . To improve the photocatalytic activity of CN, various strategies have been proposed including the construction of heterojunctions, introduction of heteroatoms, defect engineering, and the enhancement of crystallinity. , Elemental doping provides a convenient approach to tune the optical, electronic, and other physical properties of CN and thus improves its photocatalytic performance . Various elements such as boron, potassium, and cobalt were doped in CN to achieve the enhanced photocatalytic activity. − Teng et al investigated the effects of different metal dopants including Fe, Co, Ni, In, and Sn on the photocatalytic H 2 O 2 production performance of polymeric carbon nitride and found that In-doped CN showed the best photocatalytic activity .…”

“…17 To improve the photocatalytic activity of CN, various strategies have been proposed including the construction of heterojunctions, introduction of heteroatoms, defect engineering, and the enhancement of crystallinity. 18,19 Elemental doping provides a convenient approach to tune the optical, electronic, and other physical properties of CN and thus improves its photocatalytic performance. 9 Various elements such as boron, potassium, and cobalt were doped in CN to achieve the enhanced photocatalytic activity.…”