Highly active Ni atomic clusters loaded with coal gasification slag derivatives effectively remove tetracycline by activating persulfate to enhance electron transfer ability

Abstract

In this study, low-cost coal gasification slag derivative (CGD) was used as a carrier, and highly active Ni atom clusters were successfully loaded on the carrier using the electrostatic self-assembly method to prepare a Ni-CGD composite catalyst. It was used to activate persulfate (PDS) and monopersulfate (PMS) to efficiently remove tetracycline (TC) from aqueous solutions. Experimental results show that Ni-CGD/PDS and Ni-CGD/PMS system exhibits nearly 100 % degradation efficiency for TC between pH 4 and 11. PDS and PMS molecules can be adsorbed on the surface of Ni-CGD materials effectively, and a reaction center with high redox potential can be formed on the catalyst surface through the interaction between molecules. This phenomenon enhances the transfer of electrons from the relatively high-potential functional groups on the TC molecules to the catalyst surface. In addition, the strong interaction between Ni-CGD and the activator promotes the formation of more surface active sites, which can receive electrons from TC molecules, leading to the oxidative degradation of TC. Quenching experiments and EPR tests indicate that direct electron transfer is the main reaction pathway for TC degradation.