Synergistic effect of adsorption and visible-light photocatalysis for organic pollutant removal over BiVO4/carbon sphere nanocomposites

Abstract

Photocatalysis and adsorption are considered as the effective methods to remove organic pollutants in wastewaters. In this study, a novel composite, BiVO4 with reasonable bandgap (∼2.4 eV) and good photocatalytic performance combined with carbon sphere, is successfully prepared, which can be used to remove organic pollutants by the synergistic effect of adsorption and photocatalysis. In the composite, the carbon sphere has good ability to adsorb the pollutants, which is beneficial for them to be further photodegraded. Besides, it has good conductivity, which can facilitate the transfer of photogenerated electrons, thus reducing the recombination of photogenerated carriers for photocatalytic performance improvement. It is found that the composite with optimized ratio shows good adsorption and photocatalytic performance. The photodegradation rate for methylene blue over the best composite under visible-light irradiation is 11.56 times higher than that over pure BiVO4 and that for rhodamine B is 4.42 times higher. The study provides a promising photocatalyst to be used for organic pollutant removal in large scale.