Ultra-low Loading of Au Clusters on Nickel Nitride Efficiently Boosts Photocatalytic Hydrogen Production with Titanium Dioxide

Graphical Just a bit of gold : The Ni 3 N−Au c −TiO 2 catalyst exhibits a better hydrogen evolution rate under full band light irradiation as compared to those of binary Ni 3 N−TiO 2 and Au c −TiO 2 . The amount of Au c is ultralow (0.00025 wt%) with Ni 3 N in the optimum photocatalyst Ni 3 N−Au c −TiO 2 , which shows the loading of noble metal is reduced by 99.95 wt% compared with the optimal load of Pt (0.5 wt%). Platinum (Pt) is a widely used co-catalyst with excellent performance for photocatalytic hydrogen evolution. However, it is not suitable for industrial production because of its prohibitive cost. Currently, there are two means to overcome this challenge. One is to, find alternative cocatalysts for Pt. The other is to develop ultrasmall of noble metal clusters, which reduces the amount of noble metal loading required. This reduces the loading amount of noble metals and improves their atomic efficiency. In this work, we have integrated both these approaches to generate a non-noble metal co-catalyst nickel nitride (Ni 3 N) and Au clusters (Au c ). The composite cocatalyst (Ni 3 N−Au c ) thus obtained promotes photocatalytic hydrogen production of TiO 2 . The (Ni 3 N−Au c −TiO 2 ) composite with an ultralow amount of Au c (0.00025 wt%) shows photocatalytic hydrogen production rates that are even higher than that of Pt−TiO 2 . The loading requirement of noble metal is reduced by 99.95 wt% compared to the optimal load of Pt; further indicating the cost efficiency possible through this method.