Three-dimensional Graphene/MnO2 nanowires foam for photothermal-enhanced visible-light photocatalytic degradation of refractory organic pollutants

Abstract

With the rapid development of modern industry, stable organic dyes and antibiotics pollution in surface water have become emerging issues. In this study, a 3D reduced graphene oxide (rGO)/MnO₂ nanowires foam (3D rGO/MnO₂) has been developed, demonstrating excellent photothermal-enhanced visible-light photocatalytic activity for the degradation of refractory organics. The interconnected graphene network and disturbed MnO₂ nanowires endow 3D rGO/MnO₂ high UV–Vis–NIR absorption and favorable mechanical stability. The surface temperature can be increased to be about 82 ​°C under one sunlight, which will increase the carrier density, promote transport and enhance the carrier mobility to improve the photocatalytic performance. The photocatalytic degradation rate of Methylene blue (MB) is as high as 92 ​% (5 ​mg/L) and the degradation rate of tetracycline hydrochloride (TC) is 75 ​% (5 ​mg/L). Different from the traditional photocatalyst of dispersed state, this foam-like and mechanical stable 3D rGO/MnO₂ could be moved from treated water to unpurified water treatment easily that could be favorable for the practical application.