Harnessing potassium peroxymonosulfate activation of WO 3 /diatomite composites for efficient photocatalytic degradation of tetracycline.

The increasing prevalence of pharmaceutical contaminants in aquatic ecosystems poses profound challenges for both environmental sustainability and public health. Addressing this pressing issue requires the development of innovative, cost-effective, and efficient remediation approaches. Here we report the synthesis of WO 3 /diatomite composites and their photocatalytic degradation in conjunction with potassium peroxymonosulfate (PMS) activation. By leveraging the synergistic effects, we observe a remarkable degradation of tetracycline, a significant pharmaceutical contaminant, under visible light. Analytically, we have elucidated the driving factors for the enhanced performance, emphasizing the optimal amount of WO 3 (10%) in the composite and PMS concentration (3 mM). Specifically, the WO 3 /diatomite catalyst presents a degradation rate of 80.75% tetracycline (40 mg L -1 ) after 180 min of visible light irradiation. Also, we elucidate the primary roles of ˙SO 4 - radicals in driving the photocatalytic reaction using free radical trapping studies. Our approach not only offers a direct solution to controlling pharmaceutical contamination but also opens new possibilities for advancing the design of composite-based photocatalysts by taking advantage of nature-derived materials.