Effect of mixed Mo/W polyoxometalate modification on photoelectrocatalytic activity of CdS nanocrystals for arsenic(III) oxidation
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 (Ag3PMo3W9O40, Ag3PMo6W6O40, and Ag3PMo9W3O40). 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/Ag3PMo3W9O40, CdS/Ag3PMo6W6O40, and CdS/Ag3PMo9W3O40) were superior to the performance of pure CdS nanocrystals. CdS/Ag3PMo3W9O40 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.
- Publication:
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Journal of Physics and Chemistry of Solids
- Pub Date:
- June 2020
- DOI:
- 10.1016/j.jpcs.2020.109395
- Bibcode:
- 2020JPCS..14109395S
- Keywords:
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- CdS nanocrystal;
- Polyoxometalates;
- Photoelectrocatalytic oxidation;
- Arsenic