Laser Ablation Nanoarchitectonics of Au–Cu Alloys Deposited on TiO(2) Photocatalyst Films for Switchable Hydrogen Evolution from Formic Acid Dehydrogenation

[Image: see text] The regulation of H(2) evolution from formic acid dehydrogenation using recyclable photocatalyst films is an essential approach for on-demand H(2) production. We have successfully generated Au–Cu nanoalloys using a laser ablation method and deposited them on TiO(2) photocatalyst films (Au(x)Cu(100–x)/TiO(2)). The Au–Cu/TiO(2) films were employed as photocatalysts for H(2) production from formic acid dehydrogenation under light-emitting diode (LED) irradiation (365 nm). The highest H(2) evolution rate for Au(20)Cu(80)/TiO(2) is archived to 62,500 μmol h(–1) g(–1) per photocatalyst weight. The remarkable performance of Au(20)Cu(80)/TiO(2) 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(2) is vital to supply the photoexcited electrons of TiO(2) to its surface for H(2) 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.