Electrochemical oxygen generation from VO2 nanoflakes decorated onto graphite sheet

Abstract

The present study deals with the synthesis of VO2 anchored across graphite sheets using a carbothermal reduction technique. The phase identification, elemental, and morphology of the obtained VO2/graphite heterostructure were examined using analytical techniques. Morphological characterization by FESEM confirms the formation of nanoflakes like the structure of VO2/graphite heterostructure. The sample obtained was drop cast onto graphite and the material was utilized as a working electrode for the electrochemical oxygen evolution reaction (OER). The VO2/graphite heterostructure shows an overpotential of 470 mV as compared to V2O5/graphite, which has an overpotential of 800 mV during OER in alkaline media. Additionally, the VO2/graphite electrocatalyst exhibits a low charge transfer resistance of 29.5 Ω and a low Tafel slope value corresponding to 85 mV dec−1. The results signify that the VO2/graphite heterostructure has emerged as an efficient catalytic material for OER application. Therefore, the present work focuses on the simpler method for the synthesis of VO2/graphite heterostructure with long-term performance during O2 evolution and also renders the potential catalytic applications of vanadium-based metal oxide.