In-situ synthesis of 2D Z-scheme MnTiO3/g-C3N4 heterostructure for efficient electrocatalytic hydrogen production

• Published in: Journal of the Taiwan Institute of Chemical Engineers Vol. 151; p. 105085
• Main Authors: Li, Fang, Zhou, Yu, Xie, Shuting, Wu, Zeling, Wang, Qiaojun, An, Yani, Huang, Haohui, He, Qingyun, Li, Feng, Zhao, Kaiyan, Wu, Peiwei, Yu, Changlin
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2023
• Subjects: 2D g-C3N4; Carrier separation; HER; Z-scheme heterostructure; Z-scheme heterostructure; Carrier separation; 2D g-C3N4; HER
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2023.105085

•In this paper, MnTiO3 nanoparticles doped with g-C3N4 micro-nanosheets were prepared and characterized with good performance using in situ growth method.•MnTiO3/CN can exhibit superior electrochemical hydrogen precipitation performance compared to the mono-material.•The doping of MnTiO3 leads to more nitrogen defects on the surface of g-C3N4, which results in more electrochemically active sites on the surface of the•Prepared heterojunction composite samples, enabling them to make an effective improvement in electrochemical properties. Z-scheme semiconductor heterostructure promotes the practical separation of electron-hole pairs and enhances the carrier separation efficiency, which has broad application prospects in efficient electrocatalytic hydrogen production (HER). However, it remains a significant challenge to construct high-quality directly Z-scheme heterostructure effectively. In this work, the construction of stable and controllable two-dimensional (2D) Z-scheme MnTiO3/C3N4 (MTO/CN) heterostructure via In-situ growth strategy is obtained. This strategy relies mainly on the cooperation of ligand covalent bonds arising from the controlled growth of precursors and the tendency of metal ions to acquire stable electronic configurations. Benefiting from the unique electronic structure of heterostructure, the excellent performance of HER based on the MTO/CN heterostructure is systematically investigated. It reveals that the overpotential of the MTO/CN heterostructure is only 357 mV at 10 mA cm2, which is 2.02 times lower compared to the pure g-C3N4. At the same time, the ESCA results show that the value of Cdl of the heterostructure is 42.79 mF cm−2, which is 6.26 times higher compared to the pure g-C3N4. Furthermore, this strategy provides new insight and theoretical guidance for the design of the Z-scheme semiconductor heterostructure. Schematic diagram of electrochemical hydrogen precipitation of MnTiO3/CN heterojunction composites prepared by in situ growth method. [Display omitted]