Photocatalytically Active Semiconductor Cu3P Unites with Flocculent TiN for Efficient Removal of Sulfamethoxazole

Sulfamethoxazole is a widely-used antibiotic with high water solubility and low biodegradability, which was considered a refractory environmental pollutant. Hence, a series of functionalized hybrids uniting Cu3P with TiN were prepared. The Cu3P/TiN-x composites remarkably removed the sulfamethoxazole in solution compared with Cu3P and TiN alone. All the as-prepared Cu3P/TiN-x hybrids integrated the advantages of strong adsorption and photocatalysis and achieved removal rates above 70% of sulfamethoxazole. Among the composites, the Cu3P/TiN-2 with a 1:1 molar ratio of Cu: Ti reached a 90% removal rate under dark adsorption for 30 min and subsequent photodegradation for 120 min. The enhanced performance of the Cu3P/TiN-x composites is attributed to the introduced flocculent TiN with a large specific surface area and high conductivity that provide more reactive sites and high electron transferability. Meanwhile, the strong corrosion resistance and chemical stability were also beneficial to the improved performance. Cycling experiments further demonstrate the stability and reliability of the composites. In addition, the capture experiments indicated that the superoxide radical (center dot O-2(-)) and hydroxyl radical (center dot OH) played a major role in sulfamethoxazole degradation.