In-situ preparation of Z-scheme Ag2WO4/FeVO4 heterostructure composite for tetracycline degradation: Its performance and degradation pathway

A visible-light-responsive Ag 2 WO 4 /FeVO 4 heterostructure was prepared for the photocatalytic degradation of tetracycline (TC) in water. The formation of the heterostructure improved visible-light absorption, promoted interfacial charge transfer, and suppressed electron-hole recombination as revealed from the characterization techniques. The Ag 2 WO 4 /FeVO 4 composite achieved 98.51% TC degradation within 50 min, markedly higher than pristine Ag 2 WO 4 and FeVO 4 , which showed 41.54 % and 57.37 % removal, respectively. The composite also exhibited the highest apparent rate constant of 0.04654 min -1 , confirming its enhanced photocatalytic efficiency. Radical scavenging experiments indicated that superoxide and hydroxyl radicals were the major reactive species responsible for TC degradation, while recyclability tests showed that the catalyst retained 88.08% degradation efficiency after five cycles. The improved performance is attributed to the Z-scheme charge-transfer pathway, which enhances charge separation while maintaining strong redox ability. These results demonstrate that Ag 2 WO 4 /FeVO 4 is a promising photocatalyst for the treatment of antibiotic-contaminated wastewater.