Enhanced removal of organic pollutant by separable and recyclable rGH-PANI/BiOI photocatalyst via the synergism of adsorption and photocatalytic degradation under visible light

A novel three-dimension separable and recyclable rGH-PANI/BiOI photocatalyst with the synergism of adsorption-enrichment and photocatalytic-degradation was successfully prepared via a facile three-step hydrothermal method. The three-dimension reduced graphene oxide hydrogel (rGH) in with flower-like BiOI photocatalyst uniformly distributed not only possesses excellent adsorption and electron transport properties, but also is easy to be separated from water for recycling. In addition, polyphenylamine (PANI) provides superior hole transport ability due to its delocalized π-π conjugate structure. The cooperation of rGH and PANI greatly enhances the separation efficiency of photogenerated carriers, and finally improves the photocatalytic degradation behaviors. The removal rates of Rhodamine B (RhB) by rGH-PANI/BiOI-70 % composite under visible light respectively reach 100 % and 50.13 % in static and dynamic systems, which are 12.85 and 3.58 times of BiOI, respectively. The removal rate does not show decrease after 5 recycles indicating the excellent separable and recyclable property of rGH-PANI/BiOI photocatalyst. The work provides an essential reference for designing and constructing hydrogel-based ternary composite photocatalysts with excellent synergism of adsorption and photocatalysis, which shows great potential in the treatment of water pollution.