Enhancing photocatalysis in SrTiO3 by using Ag nanoparticles: A two-step excitation model for surface plasmon-enhanced photocatalysis

Lei Ma; Tao Sun; Hua Cai; Zhi-Quan Zhou; Jian Sun; Ming Lu

doi:10.1063/1.4929910

Enhancing photocatalysis in SrTiO3 by using Ag nanoparticles: A two-step excitation model for surface plasmon-enhanced photocatalysis

J Chem Phys. 2015 Aug 28;143(8):084706. doi: 10.1063/1.4929910.

Authors

Lei Ma¹, Tao Sun¹, Hua Cai¹, Zhi-Quan Zhou¹, Jian Sun¹, Ming Lu¹

Affiliation

¹ Department of Optical Science and Engineering, and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China.

PMID: 26328866
DOI: 10.1063/1.4929910

Abstract

Surface plasmon (SP)-enhanced ultraviolet and visible photocatalytic activities of SrTiO3 (STO) are observed after incorporating Ag nanoparticles (Ag-NPs) on STO surfaces. A two-step excitation model is proposed to explain the SP-enhanced photocatalysis. The point of the model is that an electron at the valence band of STO is first excited onto the Fermi level of Ag-NP by the SP field generated on the Ag-NP, and then injected into the conduction band of STO from the SP band, leaving a hole at the valence band of STO. A full redox catalytic reaction at the surface of STO is then available. For Ag-NP incorporated STO, up-converted and inter-band photoluminescence emissions of STO are observed, and nonlinear evolutions of photocatalytic activity with illumination light powers are found. Furthermore, near infrared photocatalysis is detected. These results support the proposed model.