Reusing waste plastic bottle to reduce MoO₃ into carbon-supported MoO₂ nanoparticles for efficient water electrolysis

One of the efficient ways to produce hydrogen through electrolysis of water is oxygen evolution reaction (OER). OER being an anodic process requires highly efficient, sustainable and economic electrocatalysts with long term stability. In this work, plastic water bottle is utilized as a carbon source and a reducing agent to reduce MoO₃ to carbon supported MoO₂ (MoO₂@C) as an efficient electrocatalyst for OER. The conductive carbon layers encapsulating the MoO₂ nanoparticles enhances the charge transfer rate and improves the long-term stability. The defect rich supporting carbon exhibits high specific surface area and improves the electrochemical activity of MoO₂ nanoparticles. The sample requires only an overpotential of 516 mV (vs. Ag/AgCl) to achieve a current density of 10 mA cm-2 and a low Tafel slope of 84.4 mV dec⁻¹. It displays excellent electrochemical stability up to 2000 cyclic voltammetry (CV) cycles and revealed excellent stability up to 24 h. The reported method provides an efficient way to reuse waste plastic bottle to as carbon source as well as reducing agent produce MoO₂@C electrocatalyst at an industrial scale.