Laser Ablation Nanoarchitectonics of Au-Cu Alloys Deposited on TiO Photocatalyst Films for Switchable Hydrogen Evolution from Formic Acid Dehydrogenation.

The regulation of H evolution from formic acid dehydrogenation using recyclable photocatalyst films is an essential approach for on-demand H production. We have successfully generated Au-Cu nanoalloys using a laser ablation method and deposited them on TiO photocatalyst films (Au Cu /TiO). The Au-Cu/TiO films were employed as photocatalysts for H production from formic acid dehydrogenation under light-emitting diode (LED) irradiation (365 nm). The highest H evolution rate for AuCu/TiO is archived to 62,500 μmol h g per photocatalyst weight. The remarkable performance of AuCu/TiO may account for the formation of Au-rich surfaces and the effect of Au alloying that enables Cu to sustain the metallic form on its surface. The metallic Au-Cu surface on TiO is vital to supply the photoexcited electrons of TiO to its surface for H evolution. The rate-determining step (RDS) is identified as the reaction of a surface-active species with protons. The results establish a practical preparation of metal alloy deposited on photocatalyst films using laser ablation to develop efficient photocatalysts.