Photocatalytic Activity of the Sb2O3/Ca5Al6O14 Nanoscale Composites for Crystal Violet Degradation

Background: The discharging of crystal violet dye can contaminate water and soil, which causes serious environmental pollution and health problems for human beings. Sb2O3/Ca5Al6O14 nanoscale composites possess good catalytic performance for crystal violet removal. This study aimed to research the effects of the Sb2O3 content, content of the nanoscale composites, and metallic cations on the photocatalytic activity of the Sb2O3/Ca5Al6O14 nanoscale composites. Objective: The objective was to synthesize Sb2O3/Ca5Al6O14 nanoscale composites by a simple route and research the photocatalytic activity for crystal violet degradation. Methods: Sb2O3/Ca5Al6O14 nanoscale composites were obtained via a simple route using Ca aluminate nanosheets and Sb acetate. The photocatalytic activity of the Sb2O3/Ca5Al6O14 nanoscale composites was evaluated using crystal violet as a model pollutant. Results: The obtained nanoscale composites consisted of orthorhombic Ca5Al6O14 and orthorhombic Sb2O3 phases, nanosheets with a thickness of about 50 nm, and nanoparticles with a size of less than 100 nm. Sb2O3 enhanced the light absorption ability of the Ca aluminate nanosheets. The nanoscale composites with the Sb2O3 content of 20wt.% decreased to 3.03 eV, which is beneficial for improving the photo-degradation ability of the organic pollutants. The reaction ratio constant k for crystal violet (CV) degradation was 0.045 min-1 and 0.055 min-1 using the nanoscale composites with Sb2O3 content of 10wt.% and 20wt.%, respectively, which was 1.4 and 1.7 times higher than that of the Ca aluminate nanosheets (0.032 min-1). Hydroxyl radicals (●OH), hole (h+), and superoxide radicals (●O2 −) were reaction-active species for CV removal. Sb2O3/Ca5Al6O14 nanoscale composites exhibited fast interfacial charge transfer and efficient separation ability of photo-induced electron-hole pairs, which enhanced the photocatalytic activity of the Ca aluminate nanosheets for CV degradation. Conclusion: The Sb2O3/Ca5Al6O14 nanoscale composites can be easily separated and reused, showing great potential for practical application in wastewater treatment.