Optimizing the Deposition of Hydrogen Evolution Sites on Suspended Semiconductor Particles using On-Line Photocatalytic Reforming of Aqueous Methanol Solutions

The deposition of hydrogen evolution sites on photocatalysts is a crucial step in the multistep process of synthesizing a catalyst that is active for overall photocatalytic water splitting. An alternative approach to conventional photodeposition was developed, applying the photocatalytic reforming of aqueous methanol solutions to deposit metal particles on semiconductor materials such as Ga2O3 and (Ga0.6Zn0.4)(N0.6O0.4). The method allows optimizing the loading of the co‐catalysts based on the stepwise addition of their precursors and the continuous online monitoring of the evolved hydrogen. Moreover, a synergetic effect between different co‐catalysts can be directly established. Creating gateways for electrons: The number of hydrogen evolution sites on Ga2O3‐based photocatalysts is optimized in a continuously flushed water‐splitting set‐up equipped with on‐line gas analysis. A fast sequential photodeposition method is established by monitoring the amount of hydrogen evolved from the sacrificial agent methanol.