Effect of mixed Mo/W polyoxometalate modification on photoelectrocatalytic activity of CdS nanocrystals for arsenic(III) oxidation. (June 2020)

• Record Type: Journal Article
• Authors: Song, Yuting; Fang, Wencheng; Liu, Caixia; Sun, Zhixia; Li, Fengyan; Xu, Lin
• Is Part Of: Journal of physics and chemistry of solids. Volume 141(2020)
• Publication Date: 2020-06
• Subjects: CdS nanocrystal -- Polyoxometalates -- Photoelectrocatalytic oxidation -- Arsenic; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2020.109395
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: Modification of semiconductor materials by polyoxometalates (POMs) is a promising strategy for increasing their photoelectrocatalytic (PEC) activity. In this work, we synthesized POM-modified CdS composite nanocrystals based on three kinds of Keggin-type mixed-addendum Mo/W POMs (Ag3 PMo3 W9 O40, Ag3 PMo6 W6 O40, and Ag3 PMo9 W3 O40 ). This is the first report on the semiconductor properties of the three Keggin-type mixed-addendum Mo/W POMs. Their PEC performances were studied by transient photocurrent responses, electrochemical impedance spectroscopy, and PEC oxidation of As(III) to As(V). The PEC performances of POM-modified CdS composite nanocrystals (CdS/Ag3 PMo3 W9 O40, CdS/Ag3 PMo6 W6 O40, and CdS/Ag3 PMo9 W3 O40 ) were superior to the performance of pure CdS nanocrystals. CdS/Ag3 PMo3 W9 O40 composite nanocrystals exhibited the highest efficiency for the PEC oxidation of As(III) to As(V), which was about 85% higher than that of the pure CdS nanocrystals. The present study provides insight into developing novel composite nanocrystals with Keggin-type mixed Mo/W POMs for efficient PEC oxidation. Graphical abstract: Image 1 Highlights: The semiconductor properties of three Keggin-type mixed-addendum Mo/W polyoxometalates were revealed for the first time. CdS/polyoxometalate composite nanocrystals show photoelectrocatalytic performance superior to that of pure CdS nanocrystals. The CdS/PMo3 W9 composite nanocrystals exhibit the highest efficiency for the photoelectrocatalytic oxidation of As(III).