Unexpected impact of oxygen vacancies on photoelectrochemical performance of Au@TiO2 photoanodes. (1st June 2021)

• Record Type: Journal Article
• Authors: Nguyen, Tien-Thanh; Dao, Khac An; Nguyen, Thi Tu Oanh; Ung, Thi Dieu Thuy; Nguyen, Duy Thien; Nguyen, Si Hieu
• Is Part Of: Materials science in semiconductor processing. Volume 127(2021)
• Publication Date: 2021-06-01
• Subjects: Au@TiO2 nanoparticles -- Vacuum and air annealing -- Oxygen vacancy -- Schottky barrier -- Photocatalysis -- Plasmonic solar cells; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2021.105714
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: This work investigated the effect of oxygen vacancy (OV) and Au nanoparticles on the photoelectrocatalytic activities of Au@TiO2 photoanodes. The Au@TiO2 films on FTO substrates were prepared by the spin-coating method using emulsions of Au NPs (~4 nm) and TiO2 NPs (~20 nm) dispersing in ethanol. The OV concentration in the TiO2 NPs was controlled by annealing the photoanodes in vacuum and air for different time periods. The absorbance, photoluminescence, and linear sweep voltammetry spectra of the photoanodes were investigated. The experiment results indicated that the increment of the OV concentration enhanced photoelectrocatalytic activity of the TiO2 photoanodes but moderated the activity of the Au@TiO2 photoanodes. These effects were explained based on the Schottky barrier between the Au and TiO2 nanoparticles. Graphical abstract: Image 1 Highlights: Au was decorated on TiO2 nanoparticles by reduction of AuCl4 – using NaBH4 . Oxygen vacancy concentration in the nanosystems was varied by annealing method. Oxygen vacancy concentration have opposite effects on the different nanosystems. The effects were explained based on Schottky barrier between the nanoparticles. Authors suggest that care must be taken for the doping of Au@TiO2 nanosystems.