Constructing branch architectures on fly ash surfaces to immobilize iron tetracarboxy phthalocyanine for synergistic degradation of dye contaminants

Utilization of fly ash (FA) solid wastes as the economical carrier materials to support the high active catalysts for environmental purification would contribute to the low carbon society, resource conservation and environmental improvement. For this purpose, in-depth understanding of the surface structure dependent fly ash carriers for the high efficiency immobilization of catalyst is essential. In this study, the highly active molecule catalysts of iron tetracarboxy phthalocyanine (TCFePc) complexes were successfully supported on FA for the first time. The FA particulates were successively activated to generate the dense branch crystal surfaces for immobilizing TCFePc complexes via a simple precipitation method. The TCFePc@FA composites can activate tert-butyl hydroperoxide (BuOOH) to produce hydroxyl and alkoxy radicals along with the generation of high valent iron-oxygen species to synergistically degrade high concentration organic dyes. Significantly, the TCFePc@FA-2% (2 wt% of catalyst) exhibited obviously higher catalytic efficiency than that of pure TCFePc. The immobilization mechanism and the catalytic processes of TCFePc@FA composites were discussed in detail. Our investigation provides an efficient and economical strategy for designing FA-based catalysts in the field of environmental catalysis.