In situ synthesis of bimetallic Ag/Pt loaded single-crystalline anatase TiO2 hollow nano-hemispheres and their improved photocatalytic properties

Abstract

Considering that the reduction of particle size can increase the number of active sites, particle size is accepted to be the key factor in the design of photocatalysts. However, serious agglomeration of nanosized particles may cause not only a decreased surface area but also increase grain boundary recombination. Forming a hollow nano-hemisphere in single crystals with reactive sites could be a good method to overcome this drawback. In this work, we report the synthesis of novel anatase TiO₂ hollow nano-hemispheres by using a mixture of CH₃COO⁻ and F⁻ as size and morphology controlling co-agents that prevent aggregation and increase the number of active sites. Furthermore, bimetallic Ag/Pt nanoparticles (NPs) are uniformly loaded on both interior and exterior of the nano-hemispheres in situ. The Ag/Pt@TiO₂ NPs with improved visible-light-harvesting ability, high charge–hole mobility, and low electron–hole recombination exhibited improved photocatalytic performance in the degradation of rhodamine B/ciprofloxacin (RhB/CIP) and hydrogen generation. The results presented here give a promising way toward the development of delicate bimetal@semiconductor composites for board applications in photocatalysis.