Efficient removal of formaldehyde by diatomite decorated with BiOCl/TiO2 under visible-light irradiation: Effects of key preparation parameters.

[Display omitted] • Diatomite decorated with BiOCl/TiO 2 was prepared for formaldehyde degradation. • Effects of key parameters on the photocatalytic performance was studied. • Optimal pH values, calcination temperature, and mass ration was confirmed. • BiOCl/TiO 2 @diatomite showed excellent performance of formaldehyde degradation. The diatomite decorated with BiOCl/TiO 2 (BiOCl/TiO 2 @diatomite) composites were prepared by supporting BiOCl/TiO 2 heterogeneous junction on the surface of diatomite with precipitation-calcination method. This work systematically studied the effects of terminal pH, calcination temperature, and TiO 2 /BiOCl ratio. Furthermore, the relationship between structure and photocatalytic performance of the composite was investigated. The results demonstrated that composite with optimized performance (84.1% formaldehyde degradation rate of 1.0 g photocatalyst) can be obtained at terminal pH of 6, calcination temperature of 500 °C, and TiO 2 /BiOCl ratio of 55/45. It is indicated that the phase structure, grain size, and porous structure can be significantly affected by the above preparation parameters. In conclusion, the formaldehyde adsorption and degradation properties can be enhanced by the construction of porous structure and heterogeneous junction of composites. Overall, BiOCl/TiO 2 @diatomite composites exhibited excellent formaldehyde degradation performance under visible light due to the multi-layer structure and the combination of TiO 2 and BiOCl on the surface of diatomite. [ABSTRACT FROM AUTHOR]