Efficient degradation of thiocyanate by persulfate activation of a novel SA@Fe-Ni-C composite: Properties, mechanisms and DFT calculations

作者：Xu, Wusong; Wang, Jin^*; Zhan, Xinyuan; Zhang, Min; He, Maolin; Yue, Zhengbo^*

来源：Journal of Environmental Chemical Engineering, 2023, 11(6): 111463.

DOI：10.1016/j.jece.2023.111463

• SA@Fe-Ni-C catalyst
• Advanced oxidation process
• Thiocyanate removal
• Fe3+/Fe2+ circulation
• Micro-electrolysis

The existing microelectrolytic materials are hindered in applying advanced oxidation processes due to their poor stability and easy bonding. Therefore, ternary iron-carbon microelectrolytic microspheres (SA@Fe-Ni-C) have been prepared by a simple embedding process and used to activate persulfate (PDS) to degrade thiocyanate (SCN-). The doping of Ni not only accelerates the electron transport and promotes the effective reduction of Fe3+ but also forms the cycle system of Fe2+/Fe3+ and Ni2+/Ni3+, which ensures the high catalytic activity of the catalyst. It was found that both free radicals (SO4 center dot-, center dot OH and O2 center dot-) and non-free radicals (1O2 and electron transfer) contributed to the removal of SCN-. The DFT results showed that Fe was the leading activation site of PDS, and Ni could also promote the activation of PDS. Finally, the high stability of SA@Fe-Ni-C and its anti -interference ability were verified by 5-cycle and coexistence ion experiments. This study provides some guid-ance for the synthesis of new micro-electrolytic materials and the treatment of industrial wastewater by an advanced oxidation process.