Synthesis of coal slime-based catalytic material for peroxymonosulfate activation through molten salt thermal treatment

Coal slime-based peroxymonosulfate (PMS) catalytic materials were synthesized utilizing coal slime (CS) as raw material under the N 2 atmosphere in this study. Raw and calcined coal slime were systematically characterized concerning morphologies, pore structures , chemical bonds, phase constituents, and defect density . Results show that after being calcinated with FeCl 2 ∙4H 2 O at 750 °C, the specific surface area increased by nearly 21.0 times higher than that of CS. The addition of FeCl 2 ∙4H 2 O has certain effect on the chemical bonds of calcined coal slime, i.e. the Fe elements can be fixed by the silicon aluminum skeleton with sekaninaite (Fe 2 Al 4 Si 5 O 18 ) and aluminum iron silicon (Al 0.5 Fe 3 Si 0.5 , above 650 °C) generation, and the I D /I G values increase to 2.96 for CS-FeCl 2 -750. In addition, the degradation percentage of phenol by using CS-FeCl 2 can achieve 100% in 25 min under optimized conditions. Furthermore, 1 O 2 plays a major role in phenol degradation, followed by • OH and SO 4 •− in the CS-FeCl 2 /PMS system from the quenching experiments and electron paramagnetic resonance results. Overall, the novel CS-FeCl 2 material displays good application prospects in the field of effluent treatment , with efficient utilization of carbonaceous and silicon aluminum skeleton in coal slime.