Preparation, properties, and photocatalytic mechanism of In2.77S4/BiVO4 heterostructure for tetracycline degradation

A cauliflower-like In 2.77 S 4 has been synthesized using polyvinylpyrrolidone (PVP) as a surfactant, and the In 2.77 S 4 /BiVO 4 composite photocatalysts were further prepared via a hydrothermal method. The photocatalytic activity of the samples was evaluated using tetracycline (TC) dilute solution. The photocatalytic degradation mechanism of the as-prepared composites was also discussed. Moreover, the state density and electron transfer of as-constructed composites were investigated through density-functional theory (DFT). Analysis results show that the as-hybridized products have higher photocatalytic activity than pure samples. With increasing the amount of BiVO 4 , the photocatalytic activity of the as-constructed In 2.77 S 4 /BiVO 4 composites is firstly increased and then decreased. The best photocatalytic degradation efficiency of the as-prepared composite for TC is 89.9% in 90 min, which is higher than 61% of In 2.77 S 4 and 51% of BiVO 4 , respectively. The reason of photocatalytic property enhancement is that there are chemical bonds between the interface of In 2.77 S 4 and BiVO 4 , and it is confirmed that h + plays a leading role during the photocatalytic degradation process. This work can provide a reference for the treatment of antibiotics pollution in water under solar light.