Preparation of high performance CoCuAl@SiC catalytic ceramic membrane for nonradical degradation of sulfamethoxazole

Abstract

Catalytic ceramic membranes (CCM) featuring catalytic and separating functions, show huge potential in water treatment. Nevertheless, the inability of catalytic ceramic membrane with high catalytic performance to be produced by current fabrication method are the bottleneck preventing their applications. Herein, the high performance CoCuAl@SiC CCM were successfully prepared by coating Al gel interlayer, hydrothermal reaction and annealing in reductive atmosphere. Annealing in reductive atmosphere play key role in enhancing the catalytic property of CoCuAl@SiC CCM. 99.3 % sulfamethoxazole (10 mg & sdot;L- 1) degraded by CoCuAl@SiC CCM annealing at 300 degrees C and 0.5 mM PMS in 1 min under a wide pH range of 3.5-11.0 and in the presence of anions. Quenching tests confirmed the dominant role of singlet oxygen (1O2) in SMX degradation. The abundant oxygen vacancies and redox cycles of Co3+/Co2+ and Co2+/Co0 on CoCuAl@SiC CCM are crucial for PMS activation. In addition, the SMX degradation pathways were found to comprise deamination, hydroxylation, and ring open according to the degradation intermediates of SMX. This study not only provides an approach for the preparation of catalytic membranes with excellent catalytic activity, but also sheds a novel insight into the indispensable role of oxygen vacancy.