Two-dimensional lateral anatase-rutile TiO2 phase junctions with oxygen vacancies for robust photoelectrochemical water splitting

Ming Meng; Lun Yang; Jing Yang; Yu Zhu; Chunyang Li; Hongjun Xia; Honglei Yuan; Meng Zhang; You Zhao; Fengshou Tian; Jitao Li; Kuili Liu; Lei Wang; Zhixing Gan

doi:10.1016/j.jcis.2023.05.193

Two-dimensional lateral anatase-rutile TiO₂ phase junctions with oxygen vacancies for robust photoelectrochemical water splitting

J Colloid Interface Sci. 2023 Oct 15:648:56-65. doi: 10.1016/j.jcis.2023.05.193. Epub 2023 Jun 3.

Authors

Ming Meng¹, Lun Yang², Jing Yang³, Yu Zhu³, Chunyang Li⁴, Hongjun Xia⁴, Honglei Yuan³, Meng Zhang², You Zhao², Fengshou Tian⁴, Jitao Li³, Kuili Liu³, Lei Wang⁵, Zhixing Gan⁶

Affiliations

¹ School of Physics and Telecommunication Engineering, Zhoukou Normal University, Zhoukou 466001, PR China. Electronic address: mengmingfly@163.com.
² Institute for Advanced Materials, School of Physics and Electronic Science, Hubei Normal University, Huangshi 435002, PR China.
³ School of Physics and Telecommunication Engineering, Zhoukou Normal University, Zhoukou 466001, PR China.
⁴ Henan Key Laboratory of Rare Earth Functional Materials, Zhoukou Normal University, Zhoukou 466001, PR China.
⁵ School of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, PR China. Electronic address: lei_wang@njnu.edu.cn.
⁶ Center for Future Optoelectronic Functional Materials, School of Computer and Electronic Information/School of Artificial Intelligence, Nanjing Normal University, Nanjing 210023, PR China. Electronic address: zxgan@njnu.edu.cn.

PMID: 37295370
DOI: 10.1016/j.jcis.2023.05.193

Abstract

Exploiting the photoelectrode materials with broad solar light response, high-efficient separation of photogenerated charges and abundant active sites is extremely vital yet enormously challenging. Herein, an innovative two-dimensional (2D) lateral anatase-rutile TiO₂ phase junctions with controllable oxygen vacancies perpendicularly aligned on Ti mesh is presented. Our experimental observations and theoretical calculations corroborate explicitly that the 2D lateral phase junctions together with three-dimensional arrays not only exhibit the high-efficient photogenerated charges separation guaranteed by the build-in electric field at the side-to-side interface, but also furnish enriching active sites. Moreover, the interfacial oxygen vacancies generate new defect energy levels and serve as electron donors, hence extending visible light response and further accelerating the separation and transfer of photogenerated charges. Profiting from these merits, the optimized photoelectrode yield a pronounced photocurrent density of 1.2 mA/cm² at 1.23 V vs. RHE with Faradic efficiency of 100%, which is approximately 2.4 times larger than that of pristine 2D TiO₂ nanosheets. Furthermore, the incident photon to current conversion efficiency (IPCE) of the optimized photoelectrode is also boosted within both ultraviolet and visible light regions. This research is envisioned deliver the new insight in developing the novel 2D lateral phase junctions for PEC applications.

Keywords: 2D lateral phase junctions; Oxygen vacancies; Photoelectrochemical water splitting; TiO(2) nanosheets.