Effects of Au and F co-modification by thermal shock method on the photocatalytic activity of ZnO

• Published in: Materials chemistry and physics Vol. 260; p. 124092
• Main Authors: Tran Vu, Thien Kim, Le, Tien Khoa, Hoang, Minh Son, Dang, Hoang Anh, Nguyen, Dieu Khanh An, Nguyen Hoang, Thanh Truc, Tsai, De-Hao, Nguyen, Huu Khanh Hung, Huynh, Thi Kieu Xuan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-02-2021; Elsevier BV
• Subjects: Catalysts; Catalytic activity; Crystal structure; Functional groups; Gold; HAuCl4; Light irradiation; Methylene blue; Morphology; Nanoparticles; Photocatalysis; Photocatalyst; Precursors; Surface modification; Thermal shock; Zinc oxide; ZnO; HAuCl4; Surface modification; ZnO; KF; Photocatalyst
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2020.124092

In this work, ZnO nanoparticles were surface-modified by thermal shock method with HAuCl4 and KF as precursors at different temperatures. The impacts of our modification process on the crystal structure, morphology, surface functional groups and surface composition of catalysts were characterized by XRD, TEM, FTIR and XPS spectra, respectively. Their photocatalytic activity was investigated through the degradation of methylene blue under UVA light and visible light irradiation. According to the results, our modification method successfully improved the photocatalytic activity of ZnO. Among all catalysts, the sample co-modified with Au and F at thermal shock temperature of 400 °C showed the best performance which was three times greater than that of unmodified ZnO sample under both UVA light and visible light. The enhanced photocatalytic activity of our modified catalysts can be attributed to the synergic effect of HAuCl4 and KF precursors which are able to produce Au(0) nanoparticles, Au+ ions and zinc vacancies on the oxide surface.
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•Surface modification of ZnO by thermal shock with HAuCl4 or/and KF precursors.•Improved photocatalytic activity by the synergistic effects of Au and F agents.•Surface F-modification creates the zinc vacancies on ZnO surface.•Surface Au-modification creates Au+ ions and Au(0) nanoparticles on ZnO surface.•Surface plasmon resonance effect produced by surface Au(0) nanoparticles.