Communication—Electrodeposited Co–Mo–P–TiO2 Composites Electrocatalysts for the Hydrogen Evolution Reaction

Abstract

A Co–Mo–P–TiO2 composite electrocatalyst is electrodeposited for the first time and the hydrogen evolution reaction (HER) was characterized. The HER Tafel slope and exchange current density on the Co–Mo–P–TiO2 surface were compared with Co–Mo, Co–Mo–TiO2 and Co–Mo–P electrodeposits similarly prepared with comparable Co/Mo composition ratio. The Co–Mo–P–TiO2 exhibited a very low overpotential at −10 mA cm−2 of 31 mV in a 1 M NaOH electrolyte. The electrochemical active surface area was characterized, to show that the improvement is not merely due to surface roughness but is an intrinsic effect. The role of TiO2 and P differed in the Co–Mo electrodeposit.