Constructing AgBr/BiOBr@silkworm cocoons photocatalytic degradation and antibacterial material: Based on the excellent adsorption properties of silkworm cocoons

The silkworm cocoon (SC) possesses excellent adsorption performance due to the specific composite structure. Silk fibroin, the main component of SC, possesses lots of functional groups which are suitable for attachment of ligands, it plays an important role in the adsorption and chelation of metal ions, thus making SC a meaningful carrier. As a result, SC exhibits the best adsorption effect on Malachite green (MG), reaching 86.8% within 3 h in the present work. Additionally, AgBr/BiOBr@SC visible light-driven (VLD) photocatalyst was successfully fabricated by ultrasound-assisted impregnation method with AgBr/BiOBr as a model and SC as a support. AgBr/BiOBr@SC showed a remarkable photocatalytic degradation rate for Rhodamine B (Rh B, 98.52%), MG (80.08%) and Tetracycline (TC, 70.92%) under 120 min irradiation. Besides, it displayed superior activity in Staphylococcus aureus (S. aureus) disinfection, and the antibacterial efficiency above 99% upon 20 min of visible-light irradiation. The outstanding photocatalytic and antibacterial properties were mainly attributed to intimate contact and matched energy band positions between AgBr and BiOBr, which efficiently produce more active e--h+ pairs, and availably restrict the recombination of photogenerated carriers. This work could arouse an increasing interest in designing more SC-based photocatalysts for wastewater treatment.