AgBr/diatomite for the efficient visible-light-driven photocatalytic degradation of Rhodamine B

The treatment of organic pollution via photocatalysis has been investigated for a few decades. However, earth-abundant, cheap, stable, and efficient substrates are still to be developed. Here, we prepare an efficient visible-light-driven photocatalyst via the deposition of Ag nanoparticles (< 60 nm) on diatomite and the conversion of Ag to AgBr nanoparticles (< 600 nm). Experimental results show that 95% of Rhodamine B could be removed within 20 min, and the degradation rate constant (κ) is 0.11 min−1 under 100 mW/cm2 light intensity. For comparison, AgBr/SiO2 (κ = 0.04 min−1) and commercial AgBr nanoparticles (κ = 0.05 min−1) were measured as well. The experimental results reveal that diatomite acted more than a substrate benefiting the dispersion of AgBr nanoparticles, as well as a cooperator to help harvest visible light and adsorb dye molecules, leading to the efficient visible-light-driven photocatalytic performance of AgBr/diatomite. Considering the low cost ($10 per ton) and large-scale availability of diatomite, our study provides the possibility to prepare other types of diatomite-based efficient photocatalytic composites with low-cost but excellent photocatalytic performance.