Synergetic effects of graphene–CoPc/silk fibroin three-dimensional porous composites as catalysts for acid red G degradation

Abstract

The disposal of dye wastewater is one of the hotspots of scientific research. Upon combining the ability of graphene to accelerate the hydroxyl radical generation with the Fenton system, it has shown a faster degradation rate and can be recycled, showing greater degradation efficiency than the traditional dye treatment method. Herein, a catalytic system based on the regenerated silk fibroin (SF) gel integrated with cobalt tetraaminophthalocyanine (CoTAPc)-grafted-reduced graphene oxide (RGO) sheets were fabricated, and its catalytic activity was assessed via the degradation of acid red G (ARG) at varying catalyst and H₂O₂ dosages, pH values, and temperatures. The results revealed that the three-dimensional (3D) porous RGO-CoTAPc/SF gel exhibited a much stronger catalytic behavior than the other arbitrary components due to its high surface area and synergetic hydroxyl radical generation efficiency, with the dye removal ratio by RGO-CoTAPc/SF being higher in an acidic medium than in an alkaline medium. It also increases with the increase in temperature and RGO-CoTAPc/SF and H₂O₂ dosages. Further, the catalytic oxidation process of ARG was determined, and the possible degradation mechanism of ARG has been discussed. Our results suggest that the composite materials with high catalytic activity can provide a reference for future Fenton-like catalytic systems.