Acta Phys. -Chim. Sin. ›› 2024, Vol. 40 ›› Issue (11): 2311001.doi: 10.3866/PKU.WHXB202311001

Special Issue: Solar Fuel Photocatalyst

• ARTICLE • Previous Articles     Next Articles

Built-in Electric Fields Enhancing Photocarrier Separation and H2 Evolution

Peipei Sun1, Jinyuan Zhang1, Yanhua Song2,*(), Zhao Mo1,*(), Zhigang Chen1, Hui Xu1,*()   

  1. 1 School of the Environment and Safety Engineering, Jingjiang College, Jiangsu University, Zhenjiang 212013, Jiangsu Province, China
    2 School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu Province, China
  • Received:2023-11-01 Revised:2023-12-13 Accepted:2023-12-14 Published:2023-12-25
  • Contact: Email: songyh@just.edu.cn (Yanhua Song)zhaomo@ujs.edu.cn (Zhao Mo)xh@ujs.edu.cn; Tel.: +86-15896387738 (Hui Xu)
  • Supported by:
    the National Natural Science Foundation of China(国家自然科学基金); the National Natural Science Foundation of China(21878134); the National Natural Science Foundation of China(22208129); the National Natural Science Foundation of China(22108110)

Abstract:

The construct of the internal electric field (IEF) is recognized as an effective driver for promoting charge migration and separation to enhance photocatalytic performance. In this study, one-dimensional nanorods of Mn0.2Cd0.8S (MCS) co-doped with interstitial chlorine (Clint) and substitutional chlorine (Clsub) were designed and synthesized using a one-step solvothermal method. The incorporation of Clint and Clsub led to an unbalanced charge distribution and the formation of IEF in the MCS nanorods, contributing to the improvement of photogenerated carrier kinetic behavior. Through density functional theory (DFT) calculations, the effect of Clint and Clsub doping on the activity of the MCS was visually explained by examining differences in electronic structure, charge distribution and H2 adsorption/desorption balance. Interestingly, the modulation of the energy band structure of MCS primarily resulted from the contribution of Clint, while Clsub playing a negligible role. Moreover, the Clsub further facilitated the optimization of Clint concerning the H2 adsorption-desorption Gibbs free energy (ΔGH*) of MCS. Ultimately, the ΔGH* of 0.9 Cl-MCS favored H2 production (1.14 vs. 0.17 eV), leading to a 9 times increase in photocatalytic H2 production activity compared to MCS. This investigation presents a valuable approach for constructing IEF in bimetallic sulfide photocatalysts.

Key words: Photocatalysis, H2 production, Bimetallic sulfides, Internal electric fields, Gibbs free energy