Simultaneous Ni-TiO2 coated electrodes for hydrogen evolution reaction in alkaline media

Abstract

Hydrogen is recognized as a clean and reliable energy option, and its efficient and effective production is essential for future energy systems and their deployments. In this study, Ni and Ni-TiO2 coatings are prepared on stainless steel substrates by co-electrodeposition at different deposition times and are evaluated for the hydrogen evolution reaction (HER) in alkaline media. The XRD and FESEM analyses confirm the beneficial role of TiO2 incorporation. The Ni-TiO2 electrode deposited for 7 min shows the best performance, achieving a hydrogen production rate of 51 mL cm- 2 h-1, with an energy efficiency of 21.45 %, an exergy efficiency of 21.42 %, a Faraday efficiency of 94.97 %, a Tafel slope of 0.118 V dec-1, an exchange current density of 1.04x10-4 A cm- 2, and a charge-transfer resistance of 0.068 Omega cm2. The AGREE score of 0.64 further highlights the environmental advantages. This study also represents the first application of the AGREE metric to Ni-TiO2 co-electrodeposited electrodes.