Synergetic Photocatalytic Nanostructures Based on Au/TiO2/Reduced Graphene Oxide for Efficient Degradation of Organic Pollutants

Abstract

Recently, there is crucial interest in the design and fabrication of nanocatalysts for efficient decomposition of organic pollutants in wastewater using visible light. This work reports the assembling fabrication of synergetic photocatalytic Au/TiO2/RGO nanostructures by utilizing the reduced graphene oxide (RGO) as substrate material and efficient separator for electrons and holes. The Au/TiO2 nanostructures with a ≈7 nm TiO2 particles size are dispersed uniformly on RGO nanosheets. UV–vis diffuse reflectance spectroscopy verifies that Au/TiO2/RGO nanocomposites show strong absorption of visible light. The degradation efficiency after 1 h for hydroquinone under visible light and UV light is ≈77% and ≈90%, respectively. Under visible light, the calculated apparent rates (k) of the Au/TiO2/RGO nanocomposites are 0.0112 and 0.0174 min−1 for decomposition of methylene blue and hydroquinone. That are five times greater than that of bare TiO2. The high photocatalytic activity is mainly attributed to the synergy between RGO and Au/TiO2 nanostructure. The strategy of composite nanostructures assembling on RGO is ensured to have a great practicable potential for the designing of high efficient multielement composite nanoparticles catalysts.