Facile synthesis of TiO2/Ag3PO4 composites with co-exposed high-energy facets for efficient photodegradation of rhodamine B solution under visible light irradiation. Issue 41 (26th June 2020)

• Record Type: Journal Article
• Authors: Du, Yi-en; Li, Wanxi; Bai, Yang; Huangfu, Zewen; Wang, Weijin; Chai, Ruidong; Chen, Changdong; Yang, Xiaojing; Feng, Qi
• Is Part Of: RSC advances. Volume 10:Issue 41(2020)
• Page Start: 24555
• Page End: 24569
• Publication Date: 2020-06-26
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/d0ra04183a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : TiO2 /Ag3 PO4 composites with co-exposed {101}, {010}/{100}, {001} and [111]-facets were successfully synthesized by combining hydrothermal and ion-exchange methods. Abstract : In this study, TiO2 /Ag3 PO4 composites based on anatase TiO2 nanocrystals with co-exposed {101}, {010}/{100}, {001} and [111]-facets and Ag3 PO4 microcrystals with irregular and cubic-like polyhedron morphologies were successfully synthesized by combining hydrothermal and ion-exchange methods. The anatase TiO2 nanocrystals with different high-energy facets were controllably prepared via hydrothermal treatment of the exfoliated [Ti4 O9 ] 2− /[Ti2 O5 ] 2− nanosheet solutions at desired pH values. The Ag3 PO4 microcrystal with different morphologies was prepared via the ion-exchange method in the presence of AgNO3 and NH4 H2 PO4 at room temperature, which was used as a substrate to load the as-prepared anatase TiO2 nanocrystals on its surface and to form TiO2 /Ag3 PO4 heterostructures. The apparent rate constant of the pH 3.5-TiO2 /Ag3 PO4 composite was the highest at 12.0 × 10 −3 min −1, which was approximately 1.1, 1.2, 1.4, 1.6, 13.3, and 24.0 fold higher than that of pH 0.5-TiO2 /Ag3 PO4 (10.5 × 10 −3 min −1 ), pH 7.5-TiO2 /Ag3 PO4 (10.2 × 10 −3 min −1 ), pH 11.5-TiO2 (8.8 × 10 −3 min −1 ), Ag3 PO4 (7.7 × 10 −3 min −1 ), blank sample (0.9 × 10 −3 min −1 ), and the commercial TiO2 (0.5 × 10 −3 min −1 ), respectively. The pH 3.5-TiO2 /Ag3 PO4 composite exhibited the highest visible-light photocatalytic activity which can be attributed to the synergistic effects of its heterostructure, relatively small crystal size, large specific surface area, good crystallinity, and co-exposed high-energy {001} and [111]-facets. The as-prepared TiO2 /Ag3 PO4 composites still exhibited good photocatalytic activity after three successive experimental runs, indicating that they had remarkable stability. This study provides a new way for the preparation of TiO2 /Ag3 PO4 composite semiconductor photocatalysts with high energy crystal surfaces and high photocatalytic activity.