Enhancing the Oxygen Evolution Performance by Introducing NiO-Supported Mesoporous Titanium Dioxide

Water electrolysis for hydrogen and oxygen production has considerable potential for sustainable development as a clean energy source.Herein, a controllable and reliable method is demonstrated for the doping of mesoporous TiO₂ with nickel oxide x-NTO for an efficient oxygen evolution reaction. An acetic acid-assisted soft-template method using block copolymer polyvinylpyrrolidone as a structure-directing agent successfully synthesizes x-NTO with uniform large mesopores. Compared to the pure TiO₂ mesoporous (0-NTO), all the x-NTO exhibit greatly enhanced oxygen evolution reaction (OER) activity. Furthermore, the percentage of nickel oxide greatly impacts the OER performance of x-NTO catalysts, and the ≈3.0 wt% (3.0-NTO) shows the greatest activity for OER, due to a 0.270 V decrease of the onset potential, while demonstrating an overpotential (η) of 340 mV at 10 mA cm^-2 in 1 M KOH solution and higher mass activity (66.50 mA mg^-1). Likewise, the 3.0-NTO electrode is very durable and engaged during electrolysis, without any obvious current declines or potential wandering seen during 12.0 h of electrolysis, confirming the 3.0-NTO's potential to serve as an electrocatalyst in energy conversion technologies.