Computational studies on functionalized Janus MXenes MM'CT2, (M, M' = Zr, Ti, Hf, M ≠ M'; T = -O, -F, -OH): photoelectronic properties and potential photocatalytic activities

Kuangwei Xiong; Ziqiang Cheng; Jianpeng Liu; Peng-Fei Liu; Zhenfa Zi

doi:10.1039/d3ra00303e

Computational studies on functionalized Janus MXenes MM'CT₂, (M, M' = Zr, Ti, Hf, M ≠ M'; T = -O, -F, -OH): photoelectronic properties and potential photocatalytic activities

RSC Adv. 2023 Mar 9;13(12):7972-7979. doi: 10.1039/d3ra00303e. eCollection 2023 Mar 8.

Authors

Kuangwei Xiong¹, Ziqiang Cheng¹, Jianpeng Liu¹, Peng-Fei Liu², Zhenfa Zi³

Affiliations

¹ Department of Physics, East China Jiaotong University Nanchang 330013 P.R. China xiongkw@ecjtu.edu.cn.
² Institute of High Energy Physics, Chinese Academy of Sciences Beijing 100049 P.R. China.
³ School of Physics and Materials Engineering, Hefei Normal University Hefei 230601 P.R. China.

Abstract

Motivated by the successful synthesis of Janus monolayers of transition metal dichalcogenides (i.e., MoSSe), we computationally investigated the structural, electronic, optical, and transport properties of functionalized Janus MXenes, namely MM'CT₂ (M, M' = Zr, Ti, Hf, M ≠ M', T = -O, -F, -OH). The results of the calculations demonstrate that five stable O-terminated Janus MXenes (ZrTiCO₂-I, ZrHfCO₂-I, ZrHfCO₂-III, HfTiCO₂-I, and HfTiCO₂-III), exhibit modest bandgaps of 1.37-1.94 eV, visible-light absorption (except for ZrHfCO₂-I), high carrier mobility, and promising oxidization capability of photoinduced holes. Additionally, their indirect-gap, spatially separated electron-hole pairs, and the dramatic difference between the mobilities of electrons and holes could significantly limit the recombination of photoinduced electron-hole pairs. Our results indicate that the functionalized Janus MXene monolayers are ideal and promising materials for application in visible light-driven photocatalysis.