Synthesis of Ag2CO3/TiO2/SiC with pH stability and chloride ion boosted for efficient photodegrading tetracycline under visible light

Abstract

The increasing issue of antibiotic contamination in water has sparked significant interest in seeking effective solutions. In this research, a dual Z-scheme ternary photocatalyst Ag2CO3/TiO2/SiC (ATS) was synthesized by a mechanochemical-coprecipitation method. The experimental results demonstrated that the 15 %Ag2CO3/TiO2/SiC (ATS-15) reached a remarkable tetracycline (TC) degradation efficiency of 95.87 % (k = 0.1063 min−1) after a 30 min exposure to visible light, which was 46.22 and 13.63 times more effective than SiC (k = 0.0023 min−1) and TiO2/SiC (k = 0.0078 min−1), respectively. The synergistic effect of ATS ternary structure to promote Si electron transfer and SiC surface oxidation. The photocatalytic performance of ATS-15 was greatly enhanced due to the synergistic effect of Cl− and CO3•−, achieving 95 % of TC degradation within 5 min. In the ATS-15 system, Cl− converts a portion of Ag2CO3 into AgCl and establishes a quaternary electron transfer scheme with ATS-15, thereby enhancing the performance of the photocatalyst. ATS-15 photocatalyst can maintain TC degradation rate above 90 % among pH 3 to 9. The ATS-15 system also exhibits excellent adaptability to various water environment, achieving 94.01 % TC degradation rate in natural river water, with only a 1 % reduction. A novel treatment scheme for antibiotic pollution in a complex water environment was proposed by ATS-15 photocatalyst with high pH stability and water applicability.