Low-cost and highly efficient composite visible light-driven Ag–AgBr/γ-Al2O3 plasmonic photocatalyst for degrading organic pollutants

Abstract

Visible light-driven photocatalysts have attracted a great deal of attention for their direct use of solar energy. In this paper, an efficient and low-cost visible light-driven composite photocatalyst, comprising of Ag–AgBr/γ-Al₂O₃ nanostructures, has been facilely prepared by a surfactant-controlled precipitation–deposition and subsequent light-driven route. Hollow flower-like γ-Al₂O₃ nanostructures was chosen as the support. CTAB controlled the size of the deposited nanoparticles in both the Br source and the surfactant. The microstructures, surface chemical composition, visible light-driven photocatalytic performance and mechanism have been investigated systematically by SEM, TEM, XPS and so forth. The Ag–AgBr nanoparticles were distributed uniformly on the surface of the hollow flower-like γ-Al₂O₃ nanostructures, whose specific surface area value reached 116.5 m² g⁻¹. The Ag–AgBr/γ-Al₂O₃ composite nanostructures exhibit photocatalytic advantages over pure Ag–AgBr nanoparticles, such as decomposing aromatic compounds and organic dyes within several minutes of visible light irradiation. They also have good stabilities meaning the photocatalytic activity seldom decreases even when used 5 times under visible light irradiation. Meanwhile, the amount of Ag–AgBr needed and the cost decreases significantly. Thus, the as-prepared composite photocatalyst, consisting of Ag–AgBr/γ-Al₂O₃ nanostructures, will be an efficient and low-cost material for the removal of organic pollutants under visible light irradiation.