Facile synthesis of sponge-loaded Bi₂WO₆ photocatalyst and degradation of tetracycline hydrochloride under visible light

A sponge-loaded Bi₂WO₆ catalyst was prepared through a facile physical load method by using sponge as the carrier and PVA as the immobilizing agent. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS) and element mapping. The results indicated that the addition of PVA did not impact the crystalline structure of Bi₂WO₆ and the Bi₂WO₆ catalyst had been successfully loaded to the sponge surfaces with the presence of PVA.The preparation conditions were optimized with the orthogonal experiment and confirmed by photocatalytic activity evaluation to be: 0.04 mmol PVA, the sponge-to-catalyst mass ratio of 1:1, the solid-to-liquid ratio of 8 g/L, and load temperature 100 °C. Under the optimum conditions, the average load rate of the photocatalysts was 43.24 % and the TCH photocatalytic degradation under visible light reached 94.00 %. Moreover, the sponge-loaded Bi₂WO₆ composite catalyst showed a stable photocatalytic activity under visible light irradiation.