Development of a novel beads-like In/Fe co-doped BiVO4 composite for enhanced photocatalytic degradation of tetracycline in water

An indium and iron co-doped unique bead-like monoclinic bismuth vanadate (BiVO4) was first prepared through electrospinning, high-temperature calcination, and low-temperature oil bath technology. Then it was characterized by a series of tests. Compared with the pure BiVO4, the 0.2:1:20 (mole rate) In/Fe co-doped BiVO4 exhibits relatively superior degradation performance under visible light, as it could degrade 82% of tetracycline hydrochloride within 2 hours. It also has good cycling stability, decreased by 4% after 5 cycles. The improvement of the photocatalytic degradation performance might lie in the broadening of the light absorption range, and the growing of photocurrent response and carrier lifetime. The density functional theory calculations could provide the support that the metal doping enables the bandgap energy reduction. The doping of iron generates a new hybridization energy level near the Fermi level, providing a novel channel for photo-generated electron migration and effectively suppressing the recombination of photo-generated charge carriers. The doping of indium injects new vitality into the conduction band and reduces its position, promoting the transition efficiency of photo-generated carriers.