ZnO-based visible-light photocatalyst: Band-gap engineering and multi-electron reduction by co-catalyst

Efficient ZnO based visible-light photocatalysts, Cu(II) modified CdxZn1−xO were developed by adopting a hybrid approach, consisting of band-engineering by formation of a solid solution and surface modification of co-catalysts. The CdxZn1−xO solid solution exhibited the visible-light activity for decomposing gaseous acetaldehyde, while bare ZnO showed negligible activity under visible-light. Further, the visible-light activity of CdxZn1−xO photocatalysts was greatly improved by the surface modification of Cu2+ ions. Photogenerated electrons in CdxZn1−xO are injected into the modified Cu2+ ions under visible-light irradiation, and electrons in Cu2+/Cu+ redox couples cause the efficient reduction of absorbed oxygen molecules. The strategy in the present study is a promising approach for applying ZnO-based photocatalysts for indoor applications.

Figure optionsDownload as PowerPoint slideResearch highlights▶ ZnO based visible-light photocatalyst has been developed by hybrid approach. ▶ One is the formation of CdxZn1−xO for effective visible-light absorption. ▶ Another is surface modification of Cu2+ ions to cause the multi-electron reduction. ▶ The present ZnO based photocatalyst is promising for indoor applications.