Simultaneous activation of KHSO5 and BuOOH by iron octacarboxyphthalocyanine loaded on fly ash microspheres to boost pollutant degradation

Abstract

Utilization of fly ash (FA) wastes as the carriers of catalysts for the environmental application is an economic and practical strategy for their low cost, easy accessibility and thermal stability. However, most catalysts immobilized on fly ash were metal or metal oxides, some potential catalysts such as metal phthalocyanine complexes have not been reported upon their heterogeneous catalysis with FA as the carriers. In this paper, highly active iron octacarboxyphthalocyanine were immobilized onto the bird nest-like surfaces of fly ash microspheres after NaOH activation. It is noted that the FeOCPc@FA composites with only 2 wt.% exhibited the high catalytic efficiency in the organic dye degradation. The high concentration of 30 mg/L rhodamine B and methylene blue could be fast decolorized in the presence of FeOCPc@FA–2 % and KHSO5. Moreover, the ultrafast decolorization of these dyes could be observed in the catalytic system composed of FeOCPc@FA–2 %, KHSO5 and BuOOH (tert-butyl hydroperoxide). Simultaneous activation of KHSO5 and BuOOH could be realized in our designed catalytic system. Based on the structural characterizations of composites and active species generated during the catalytic processes, the probable generation pathway of metal–oxygen active species and various radicals were analyzed to explicate the catalytic mechanism. Our investigation provides a high efficiency, low cost and environmentally friendly strategy for advanced oxidation treatment of organic pollutants.