Bioinspired Interfacial Spontaneous Growth of ZnO Nano catalysts onto Recycled Textiles as a Sustainable Approach for Water Purification

Zinc oxide (ZnO), as a commonly used photocatalytic degradation of organic pollutants, typically shows limitations in wastewater treatment, such as aggregation and recycling problems caused by nanoscale dimensions and inappropriate substrates. Anchoring ZnO on substrates is a strategy to obtain stable catalytic performance. Particularly, natural fiber with hollow structures is an attractive alternative for ecological and economical ZnO loading templates, but depositing ZnO onto hollowed fiber surfaces presents a challenge. Here we report a straightforward in situ growing method for producing nanostructured zinc oxide on cotton fibers from recycled garments. The modified polydopamine on the fiber surface captures the catalyst required for in situ growth of ZnO and serves as a platform for spontaneous catalytic crystal growth on the fiber surface. The ZnO nanocrystals are uniformly dispersed on the outer and inner walls of cotton fibers, demonstrating excellent durability in wastewater treatments. Moreover, the photocatalytic performance of functional fibers is optimized by doping Ag nanoparticles to improve degradation efficiency. It can extend prospects of further applications of developed ZnO/fibers in optoelectronics, spintronics, and an inspiration about recycling and upgrading of used garments