Silver nanoparticles modified reduced graphene oxide wrapped Ag3PO4/TiO2 visible-light-active photocatalysts with superior performance. Issue 49 (3rd May 2016)

• Record Type: Journal Article
• Authors: Cui, Can; Qiu, Yiwei; Hu, Haihua; Ma, Ni; Li, Shuang; Xu, Lingbo; Li, Chaorong; Xu, Jin; Tang, Weihua
• Is Part Of: RSC advances. Volume 6:Issue 49(2016)
• Page Start: 43697
• Page End: 43706
• Publication Date: 2016-05-03
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra03420a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Rational design of a novel Ag3 PO4 /TiO2 /Ag-rGO photocatalyst with both electron and hole pathways for charge separation. Abstract : Silver nanoparticles (Ag NPs) modified reduced graphene oxide wrapped Ag3 PO4 /TiO2 (Ag3 PO4 /TiO2 /Ag-rGO, Ag-ATG) photocatalysts have been developed through a rational design that combines the optimization of charge generation, separation and transfer in the composites, which helps to increase the photocatalytic performance. The Ag-ATG composites possess novel microstructure, in which TiO2 mesoporous spheres of hundreds of nanometers in size are decorated with dense nano-sized Ag3 PO4 to form pinecone-liked Ag3 PO4 /TiO2 particles, which were further wrapped by rGO sheets that are selectively decorated with Ag NPs. The Ag-ATG composites exhibit improved photocatalytic performance toward degradation of methylene blue (MB) and methyl orange (MO) under visible light compared to bare Ag3 PO4 and Ag3 PO4 /TiO2 /rGO (ATG). The underlying mechanism has been studied based on the results of reactive oxygen species capture experiment, photoluminescence (PL) spectra, and photocurrent measurements under visible light and monochromatic lights. The improved photocatalytic performance is mainly ascribed to the efficient spatial separation of photo-induced electrons and holes in Ag-ATG, i.e., the electrons in Ag3 PO4 transfer to Ag-rGO, meanwhile the holes in Ag3 PO4 transfer to TiO2 . Ag NPs play an important role in the hybrid structure owing to the synergistic effect of Ag NPs and rGO, which not only enhance the light harvest but also increase the capacity of electron accepting from Ag3 PO4 . Meanwhile, active photo-induced electrons at the plasmonic Ag NPs can facilitate the formation of O2 ˙ − radicals for photocatalysis. As a result, both the stability and photocatalytic active of Ag-ATG are significantly improved.