Hydrothermal controlled growth of MoTe2/MoO3−x materials: Synthesis mechanism, light-matter interaction and its photoelectrochemical activity

Abstract

1 T′ phase molybdenum ditelluride (1 T′-MoTe2) is predicted to be a novel two-dimensional topological insulator that will play a crucial role in future applications ranging from spintronics to quantum electronic devices. Adjusting the introduction to O in MoTe2 is used to tune the charge separation efficiency, which charge to transfer regulation is a challenge. Here, we report the controllable growth of MoTe2/MoO3−x based on the regulation of experimental parameters, and it is necessary to reveal its structure-activity relationship. The characterization result indicated that due to the existence of unsaturated bonds between atoms due to the increase in temperature, the growth direction of nanosheets changes from lateral to agglomeration and stacks into different external morphologies. In addition, the electronic and bonding properties of the MoTe2 surface layer before and after the introduction to O was investigated by photoluminescence spectroscopy and density functional theory calculations. The results suggest that O is absorbed at defect sites and disrupts the Mo-Te covalent bond, resulting in a shift in the characteristic energy level within the optical bandgap. It is demonstrated that the surface of MoTe2 exhibits a higher level of metallic conductivity after O intercalation into tellurium vacancies. The photoelectrochemical experiment results show that MoTe2 after introduction to MoO3−x has optoelectronic properties and are attractive photoelectrochemical materials. Therefore, this work has made significant progress of the study of low-temperature preparation of 1 T′-MoTe2 and the introduction to MoO3−x on its optical properties and electrochemical properties.