Electrochemical oxygen generation from VO2 nanoflakes decorated onto graphite sheet

• Published in: Journal of alloys and compounds 2024-03, Vol.976, p.173058, Article 173058
• Main Authors: Usmani, Ahmed Belal Salik, Rana, Supriya, Arora, Arushi, Yadav, Krishna K., Sammi, Heena, Sardana, Neha, Jha, Menaka
• Format: Article
• Language: English
• Subjects: Carbothermal Reduction; Electrochemical Characterization; Heterostructure; Oxygen evolution reaction; Vanadium dioxide
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.173058

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. [Display omitted] •VO2/graphite heterostructure synthesized by carbothermal reduction method.•Morphological micrographs confirms that vanadium is anchored over graphite sheet.•VO2/graphite heterostructure has flake morphology with average length of size 1 µm.•VO2/graphite heterostructure shows an η10 of 470 mV for oxygen evolution reaction.