Utilization of rice husk ash for sustainable synthesis of titania nanoparticles on ordered SBA-15 mesopores with high photoactivity and stability

Rice husks (RHs) are an agricultural waste. Currently, the waste is not effectively utilized, resulting in environmental pollution. This study is focused on the SBA-15-supported TiO 2 catalyst fabricated from RH ash (RHA) as a novel material for near-ultraviolet-light degradation of Congo red (CR). Experimental results show that the formation of new Si–O–Ti bonds was beneficial to photocatalytic reaction. The textural parameters of catalysts were in the ranges of 156–327 m 2 /g, 0.204–0.462 cm 3 /g, and 7.51–9.58 nm. The optimal catalytic conditions were a TiO 2 content of 30 wt%, calcination temperature of 900 °C, solution pH of 1, composite dosage of 50 mg, and initial CR concentration of 40 ppm. Nearly complete degradation was achieved within 120 min. The kinetics analysis, degradation mechanism, and stability of the recycled catalyst were also explored in depth. Recycling RHA to prepare mesoporous photocatalysts can simultaneously treat biowaste and purify wastewater and has high economic value.