Synergistic effect of diatomite and Bi self-doping Bi2MoO6 on visible light photodegradation of formaldehyde

Good indoor air environment is of great significance for the health and comfort assurance of occupants. In this work, a series of bismuth self-doping Bi2MoO6/diatomite (BD-X) composites with different proportions of bismuth and molybdenum source were prepared via a mild solvothermal process. Under visible light irradiation, the BD-3 sample exhibited the optimal formaldehyde (HCHO) mineralization performance, and the corresponding calculated rate constant was up to 3.2 times higher than that of bare Bi2MoO6 (B). The introduction of diatomite as catalyst carrier could not only contribute to the dispersion of nano-scale Bi2MoO6 photocatalyst, but also promote the exposure of (001) crystal plane of Bi2MoO6. In particular, the molybdenum vacancy generated with increasing the proportion of bismuth source, which effectively facilitated the separation of photogenerated carriers. Moreover, the photogenerated holes (h+) played the major role in the photocatalytic degradation process. Overall, this research would provide a novel binary composite photocatalyst derived from natural mineral for the high-efficient mineralization of formaldehyde under visible light.