Synthesis of photosensitive catalysts with wide-band absorption and ability to enhance the degradation of polyester fabric wastes

With the rapid development in textiles, leathers and plastics, non-degradable poly(ethylene terephthalate) (PET) have become one of the major environmental concerns world widely. Although catalytic depolymerization techniques of PET small pellets have been reported with requirements for additional conditions (alkaline, solvent or high temperature), simpler and cleaner approaches with high degradation efficiency are highly desirable for the management of the large-scale PET fabric wastes. In this study, we have developed a series of photocatalysts (doped Ce0.9Fe0.1O2, complex FeOx/g-C3N4 with a disordered structure and Fe2O3/g-C3N4 with an ordered structure) for PET degradation with high stability, low toxicity, and no requirement for any additional condi-tions. These photocatalysts could work at a wide range of wave lengths from 200 nm to 800 nm and elicit up to 64 % reduction in the tensile strength of PET fabrics after exposure for 125 h. Proven by FTIR and XPS analysis, the degradation of PET fabrics was mainly caused by the ester bond breakage. We have proposed the possible degradation mechanisms of PET under the photo-catalysis. The developed photocatalysts provided a feasible approach for the acceleration of the degradation of PET fabric wastes and would put considerable impact in reducing the environmental burden of disposed textiles generated from polyester and its blends.

Automated summary

A series of photocatalysts were developed for the degradation of PET fabric wastes, providing a simpler and cleaner approach with high degradation efficiency. These photocatalysts could work at a wide range of wavelengths and reduce the tensile strength of PET fabrics by up to 64% after 125 hours of exposure. The degradation of PET fabrics was mainly caused by the breakage of ester bonds. This study proposes feasible mechanisms for the degradation of PET under photocatalysis, which can significantly reduce the environmental burden of disposed textiles.