Biochar with root pore channels loaded copper cobalt bimetallic metal organic framework for effective peroxomonosulfate activation to degrade organic pollutants

Abstract

Biochar (BC) with root pore channel structure was used as the carrier, and bimetallic organic framework (CuCo-MOF) as the main active site. The CuCo-MOF was successfully dispersed in the internal channels of BC by in situ reaction, forming a composite catalyst (BC/CuCo-MOF(10 %)) with unique reaction channels. The degradation efficiency of ciprofloxacin (20 mg/L) in only 25 min was 96.4 %, and its catalytic performance was superior to that of the single BC and CuCo-MOF. On the one hand, abundant CuCo-MOF reaction sites were distributed in the relatively closed porous reaction channel of BC, which accelerated the mass transfer process (short mass transfer distance) during the CIP degradation process and improved the CIP degradation performance. On the other hand, highly conductive BC facilitates electron transfer between Cu2+/Cu+ species and HSO5-, accelerating the redox cycle of Cu2+/Cu+, thereby improving catalytic activity. Besides, the composite catalyst was still able to achieve a degradation efficiency of 87.6 % for CIP after five cyclic degradation experiments. The concentrations of Cu and Co ions in the reaction solution were only 0.04 and 0.03 mg/L. Therefore, the composites have excellent catalytic activity and stability. Both non-radical 1O2 and radicals (SO4·- and ·OH) were involved in the reaction, and the non-radical 1O2 pathway played a dominant role in the CIP degradation process.