Simultaneous Cr(VI) reduction and bisphenol A degradation by a 3D Z-scheme Bi2S3-BiVO4 graphene aerogel under visible light

Rational design strategy and facile synthesis method of photocatalysts with high efficiency and stability have been still a significant challenge for the removal of environmental contaminants. In this study, a three dimensional (3D) all-solid-state Z-scheme heterojunction photocatalytic system containing bismuth sulphide (Bi 2 S 3 ) and bismuth vanadate (BiVO 4 ) was constructed as Bi 2 S 3 -BiVO 4 graphene aerogel (SVGA) by a facile hydrothermal method. The potential application of as-synthesized SVGA was demonstrated to remove Cr(VI) and bisphenol A (BPA) simultaneously in aqueous media via the synergy of adsorption and photocatalysis under visible light irradiation. The removal rates of Cr(VI) and BPA both nearly reached 100% after adsorption for 40 min and photocatalysis for 120 min under visible light (λ > 420 nm), which was much better than the removal efficiency of individual Bi 2 S 3 and BiVO 4 , as well as Bi 2 S 3 graphene aerogel (SGA) and BiVO 4 graphene aerogel (VGA) samples. The rGO played an important role as photoinduced electron transfer mediator between Bi 2 S 3 and BiVO 4 , which promoted the photogenerated electrons transfer efficiency and enhanced photocatalytic ability of SVGA efficiently. The harmful Cr(VI) was conserved into hypotoxic Cr(III) and BPA was degraded into CO 2 and H 2 O after photocatalysis on SVGA, and the fabricated SVGA also presented favorable stability and satisfactory application effect in practical water samples, implied that such photocatalyst has a promising application for simultaneous removal of heavy metals and organics from aqueous environment.