Laser Ablation Nanoarchitectonics of Au-Cu Alloys Deposited on TiO2 Photocatalyst Films for Switchable Hydrogen Evolution from Formic Acid Dehydrogenation

Dachao Hong; Aditya Sharma; Dianping Jiang; Elena Stellino; Tomohiro Ishiyama; Paolo Postorino; Ernesto Placidi; Yoshihiro Kon; Kenji Koga

doi:10.1021/acsomega.2c03509

Laser Ablation Nanoarchitectonics of Au-Cu Alloys Deposited on TiO₂ Photocatalyst Films for Switchable Hydrogen Evolution from Formic Acid Dehydrogenation

ACS Omega. 2022 Aug 22;7(35):31260-31270. doi: 10.1021/acsomega.2c03509. eCollection 2022 Sep 6.

Authors

Dachao Hong¹, Aditya Sharma¹, Dianping Jiang², Elena Stellino³, Tomohiro Ishiyama⁴, Paolo Postorino⁵, Ernesto Placidi⁵, Yoshihiro Kon¹, Kenji Koga²

Affiliations

¹ Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST) 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
² Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology, (AIST) 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
³ Physics and Geology Department, University of Perugia, Via Alessandro Pascoli, 06123 Perugia, Italy.
⁴ Research Institute for Energy Conservation, National Institute of Advanced Industrial Science and Technology, (AIST) 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
⁵ Physics Department, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Rome, Italy.

Abstract

The regulation of H₂ evolution from formic acid dehydrogenation using recyclable photocatalyst films is an essential approach for on-demand H₂ production. We have successfully generated Au-Cu nanoalloys using a laser ablation method and deposited them on TiO₂ photocatalyst films (Au _x Cu_100-x /TiO₂). The Au-Cu/TiO₂ films were employed as photocatalysts for H₂ production from formic acid dehydrogenation under light-emitting diode (LED) irradiation (365 nm). The highest H₂ evolution rate for Au₂₀Cu₈₀/TiO₂ is archived to 62,500 μmol h^-1 g^-1 per photocatalyst weight. The remarkable performance of Au₂₀Cu₈₀/TiO₂ 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 TiO₂ is vital to supply the photoexcited electrons of TiO₂ to its surface for H₂ 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.