Controlled preparation of hollow SnO2@M (M = Au, Ag) heterostructures through template-assist method for enhanced photocatalysis

• The SiO2 particles as template are used to prepare hollow SnO2 particles.
• Au and Ag nanoparticles have been coated on the surface of SnO2.
• Direct Schottky contact (Au/SnO2) shows better photocatalytic activity than that of ohmic contact (Ag/SnO2).
• The enhanced photocatalysis has been quantitatively interpreted by the FDTD simulations.

According to relative energy band positions between noble metals of Au, Ag, and wide bandgap semiconductor SnO2, Au, and Ag nanoparticles (NPs) modified hollow SnO2 NPs were designed. Firstly, the hollow SnO2 NPs have been synthesized by employing the silica template-assisted hydrothermal methods, then Au and Ag were coated on the surface of SnO2 to form the core–shell structures, respectively. The morphology, composition, and optical properties of as-prepared samples have been investigated by various analytic methods. Subsequently, the photocatalytic reaction to Rhodamine B (RhB) dye under simulated-sunlight irradiation was employed to investigate their photocatalytic performance, the results demonstrate the metal–semiconductor with direct Schottky contact exhibited remarkable photocatalytic activity. The finite difference time domain (FDTD) calculation results illustrate the introduced and decorated Au and Ag NPs could enhance the harvesting abilities for visible light. We envision the aforementioned synthesized strategy and catalytic results are used to the designing and application of other metal–semiconductor system.

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