Effect of rGO on Fe2O3–TiO2 composite incorporated NiP coating for boosting hydrogen evolution reaction in alkaline solution

Abstract

Fe2O3–TiO2 composite incorporated NiP coating is a known promising catalytic coating for electrocatalytic Hydrogen Evolution Reaction (HER). It is explored in the present study that the activity of the coating can be enhanced by incorporation of rGO. The Fe2O3–TiO2/rGO, electrocatalyst is synthesized by a facile hydrothermal method. Various compositions of the Fe2O3–TiO2/rGO incorporated NiP coatings on mild steel substrate are developed by a chemical reduction method. The developed Fe2O3–TiO2/rGO composite coating exhibits effective hydrogen evolution reaction activity with a Tafel slope of 98 mV dec−1 and a low overpotential of 96 mV at a current density of 10 mA cm−2. The hydrogen evolution reaction mechanism comprises of Volmer (adsorption of Hydrogen atom) followed by Heyrovskii (reduction to H2). The enhanced catalytic activity by the incorporation of rGO into the coating is due to three dimensional projections of nano Fe2O3–TiO2 on the folded surface of rGO. It effectively enhances the electrochemically active surface area of the coated electrode. The electrode is highly stable during alkaline HER. These results reveal that Fe2O3–TiO2/rGO can be treated as an effective electrocatalyst during HER from alkaline solutions. The conclusions pave the way for exploration of new similar catalysts for other applications.