PVP assisted synthesis of high efficient BiOI/Graphene oxide nanohybrid and its photocatalytic performance in degradation of organic dye pollutants

In this paper, highly visible-light active BiOI/Graphene oxide nanohybrids (BG) were synthesized by a simple solvothermal technique using polyvinylpyrrolidone (PVP). The as-synthesized photocatalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transition electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) and UV-vis diffusive reflectance spectra (UV-vis DRS). The nanohybrid samples synthesized with PVP (BGP) showed extremely high efficiency in photodegradation of Reactive Blue 19 (RB19) under visible light. Specially, BGP-1 photocatalyst (1 wt% of graphene oxide (GO)) exhibited the highest RB19 degradation efficiency (about 100%) in 120 min, which was almost 60% and 65% higher than that achieved by using as-synthesized BG nanohybrids and pure BiOI particles, respectively. The results showed that PVP plays a crucial role as a template and strongly controls the growth of BiOI nanoparticles on the surface of graphene nanosheets. The enhanced photocatalytic performance of BGP-1 nanohybrids could be attributed to significant synergetic effects between graphene and BiOI nanoparticles, higher visible light absorption capacity and migration of photoexcited electrons on high conductive graphene nanosheets. This research suggests that BGP nanohybrid is a promising material for the photodegradation of organic dye pollutants under visible light irradiation and could be used commercially in wastewater treatment units.