Zn/Fe bimetallic modified Spartina alterniflora-derived biochar heterostructure with superior catalytic performance for the degradation of malachite green

In this study,the synchronous magnetized carbonization method was utilized for preparing photocatalysis ZnO-Fe@SC heterostructure,which exhibited degradation efficiency 99.14%(60 min)for malachite green(200 mg/L)and could still maintain good performance after 5 cycles.The prepared ZnO-Fe@SC was analyzed using UV-Vis DRS,PL,SEM,TEM,BET,FTIR,XPS and VSM,and LC-MS for degradation products.The results indicate that photocatalyst has favorable magnetic properties,chemical stability and low charge carriers(e^(−)/h^(+))recombination rate.The modification of bimetals enables the composite photocatalyst to enhance the intensity of photogenerated electron transition.Moreover,quenching experiment revealed that the photo-generated holes(h^(+))and superoxide radicals(·O_(2)^(−))were the dominant active species during the photocatalytic process,which degraded malachite green into small molecules by demethylation,deamination,ring-opening reactions as deducted from LC-MS analysis.ZnO-Fe@SC was prepared using a green,safe,low cost and operable synthetic method,which has a broad market potential in the field of environmental remediation.