Effect of TiO2 content on Ni/TiO2 composites electrodeposited on SS316L for hydrogen evolution reaction

Composite Ni/TiO2 catalysts have gained enormous interest in recent years in both electrocatalysis and photoelectrocatalysis for the generation of hydrogen. However, there are no systematic studies of the synthesis and characterization of these materials for applications in energy storage. In this work, three Ni/TiO2 catalysts were synthesized starting from nickel electrodeposition on AISI 316 L stainless steel with a modified Ni Watts bath, where different TiO2 contents have been added (0.1, 0.3, and 0.5% w/v). The mechanism of composite formation was studied at different electrodeposition times, in order to analyze the early periods of synthesis, reaching a chemically and structurally stable material after 45 min. It was found that all Ni/TiO2 catalysts present catalytic activity towards hydrogen generation, higher than that found by plating with a conventional Ni Watts. Particularly, the Ni/TiO2(0.3) catalyst presents increases in hydrogen formation efficiency of 75.3% and 67.8% at 298 K and 323 K, respectively.