Highlights

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The rice-like nitrogen doped titanium dioxide (N-TiO2) is synthesized.

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Hierarchical Ag nanoparticles are auto-decorated on N-TiO2 (h-Ag/N-TiO2).

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The photoinduced growth process of self-assembled h-Ag/N-TiO2 is revealed.

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Photocatalyst h-Ag/N-TiO2 exhibits a high hydrogen production rate under solar light.

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Photocatalytic mechanism of photo-splitting ethanol into hydrogen is discussed.

Abstract

The hierarchical Ag NPs with a bimodal size distribution were auto-decorated on the surface of rice-like N-TiO2 (named h-Ag/N-TiO2) by semiconductor-metal double excitation process under solar light irradiation. The photoinduced growth process of self-assembled h-Ag/N-TiO2 and its photocatalytic mechanism of photo-splitting ethanol into hydrogen have been discussed in detail. The synthesized h-Ag/N-TiO2 as a plasmonic photocatalyst for photo-splitting ethanol exhibited a higher hydrogen production rate (4.7 mmol h−1 g−1) than Ag NPs universally loaded N-TiO2 (3.4 mmol h−1 g−1) and pure N-TiO2 (2.1 mmol h−1 g−1). This work presents a reversed photo-induced synthesis strategy to design a stable Ag-TiO2 plasmonic photocatalyst with high photocatalytic efficiency under solar light. A better understanding of this solar light induced self-assembled process for Ag-TiO2 is crucial in developing metal-semiconductor system for solar energy materials.

Graphical abstract

Hierarchical Ag NPs with a bimodal size distribution are auto-decorated on the surface of rice-like N-TiO2 (named h-Ag/N-TiO2) by a reversed photo-induced synthesis method. The synthesized h-Ag/N-TiO2 as a plasmonic photocatalyst for ethanol photo-splitting exhibits an enhancement photocatalytic hydrogen production rate under solar light.

Photocatalytic test

Photocatalytic splitting ethanol into H2 was carried out in a CEL-SPH2N hysrogen evolytion system (Beijing China Education Au-light Co., Ltd) equipped with a 300W Xe lamp (CEL-HXF 300E)