From CO2 capture to high-efficient and over-stable core-shell bimetallic catalysts for eliminating sulfamethoxazole

Abstract

Herein, we prepare a series of core-shell bimetallic catalysts NixCo1-x@C (x = 0–1) with different graphitized degrees by the one-step molten salt electrolysis (MSE) method. During the catalytic oxidation experiments, sulfamethoxazole (SMX) degradation rates reach 85.60%, 100%, 100%, 98.79%, and 57.60%, respectively, as the x values increases from 0 to 1. Therefore, the alloying of Ni significantly increases the catalytic elimination performance of SMX by the NixCo1-x@C catalyst (x = 0.3) with a reaction rate (kobs) of 0.153 min−1. In addition, increasing the Ni content increases the graphitization of the carbon shell. The value of ID/IG decreases to 0.81 when the x value is 0.7, reducing the metal Ni and Co leaching of Ni0.7Co0.3@C catalyst to as low as 0.45 and 0.16 mg L−1 during the cycle's experiments, respectively. The electron paramagnetic resonance (EPR) tests and classical quench experiments show that SO4•–, •OH, O2•–, and 1O2 co-degrade the SMX.