Enhanced interfacial charge transfer on strain-induced 2D-1D/MoS2-TiO2heterostructures for electrochemical and photocatalytic applications

Priyanka Bamola; Saurabh Rawat; Manushree Tanwar; Mohit Sharma; Charu Dwivedi; Rajesh Kumar; Himani Sharma

doi:10.1088/1361-6528/ac73a3

Enhanced interfacial charge transfer on strain-induced 2D-1D/MoS₂-TiO₂heterostructures for electrochemical and photocatalytic applications

Nanotechnology. 2022 Jul 7;33(39). doi: 10.1088/1361-6528/ac73a3.

Authors

Priyanka Bamola¹, Saurabh Rawat¹, Manushree Tanwar², Mohit Sharma³, Charu Dwivedi⁴, Rajesh Kumar², Himani Sharma¹

Affiliations

¹ Functional Nanomaterials Research Laboratory, Department of Physics, Doon University, Dehradun, Uttarakhand 248001, India.
² Materials and Device Laboratory, Department of Physics, Indian Institute of Technology, Indore-453552, India.
³ Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Innovis, #08-03, Singapore 138634, Singapore.
⁴ Department of Chemistry, Doon University, Dehradun, Uttarakhand 248001, India.

PMID: 35617938
DOI: 10.1088/1361-6528/ac73a3

Abstract

Two-dimensional (2D)/one dimensionsal (1D)-MoS₂/TiO₂heterostructures have proven to be potent for photocatalytic applications. Enhancement of a heterostructure's photocatalytic activity may be influenced by the accumulation of strain at the interface, which affects the interfacial interaction. Keeping this in mind, the present paper reports strain-accumulated interfacial modification of 2D/1D-MoS₂/TiO₂heterostructures for the enhancement of photocatalytic activity. Two different synthesis methods, namely the hydrothermal and chemical vapor deposition (CVD) methods, are used for the growth of MoS₂on TiO₂nanostructures. Micro-Raman spectroscopy reveals that strain is accumulated at the interface of the growth of the MoS₂over the TiO₂nanostructures. It is further revealed that the MoS₂/TiO₂heterostructure synthesized by the CVD method induces compressive strain. Also, the heterostructure synthesized by the hydrothermal method induces tensile strain that modifies the charge separation at the interface, which is further confirmed by x-ray photoelectron spectroscopy (XPS). Moreover, ultraviolet photoelectron spectroscopy (UPS) reveals upward band-bending in the MoS₂/TiO₂heterostructure synthesized by the hydrothermal method. Similarly, the heterostructure synthesized by the CVD method shows downward band-bending that leads to improved charge separation at the interface. The modified interfaces of the heterostructures are further studied for electrochemical measurements using cyclic voltammetry (CV) and photocatalytic activity by degradation of a model compound.

Keywords: electrochemical; heterostructures; interface; photocatalysis; strain.