Photoresponses of Supported Au Single Atoms on TiO2(110) through the Metal-Induced Gap States

Shihui Dong; Bin Li; Xuefeng Cui; Shijing Tan; Bing Wang

doi:10.1021/acs.jpclett.9b01527

Photoresponses of Supported Au Single Atoms on TiO₂(110) through the Metal-Induced Gap States

J Phys Chem Lett. 2019 Aug 15;10(16):4683-4691. doi: 10.1021/acs.jpclett.9b01527. Epub 2019 Aug 6.

Authors

Shihui Dong¹, Bin Li¹, Xuefeng Cui¹, Shijing Tan¹, Bing Wang¹

Affiliation

¹ Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China.

PMID: 31364858
DOI: 10.1021/acs.jpclett.9b01527

Abstract

When a metal single-atom (SA) catalyst is supported on a semiconducting photocatalyst, the charge transfer of the photoexcited carriers to metal SAs can provide a synergetic activity for the co-catalysts. Here, we report the interfacial electronic coupling of the Au SAs on the TiO₂(110) surface using scanning tunneling microscopy/spectroscopy, in combination with first-principles calculations. Distinct energy and spatial distributions of the metal-induced gap states (MIGSs) are experimentally revealed for the Au SAs adsorbed at the terminal Ti sites and the oxygen vacancies. The localized MIGS below the Fermi level provides a dedicated channel for the transfer of a photoexcited hole from the TiO₂ substrate to the adsorbed Au SAs. The hole can weaken the Ti-Au bonding and activate the diffusion of Au SAs. Our results shed light on combining the advantages of photocatalysis and metal SA catalysis using a co-catalyst, which is promising to promote chemical reactions at low temperatures.