Enhanced piezo-induced photocatalytic activity of BaTiO3/Cd0.5Zn0.5S S scheme heterojunction for water pollution remediation: Performance, degradation pathway, and toxicity evaluation

Pharmaceutical pollutants in water pose a threat to ecosystems and human health by disrupting aquatic life, contributing to antibiotic resistance, and causing hormonal imbalances and increased disease susceptibility in humans. Thus, we report the fabrication of a novel BaTiO 3 /Cd 0.5 Zn 0.5 S heterojunction for the piezo-photocatalytic degradation of ciprofloxacin (CIP) in wastewater. The BaTiO 3 /Cd 0.5 Zn 0.5 S was synthesized via solvothermal deposition of Cd 0.5 Zn 0.5 S (CZS) onto BaTiO 3 (BTO) nanorods. This heterojunction exhibited superior photocatalytic activity, degrading ciprofloxacin ~85% and ~3 times more effectively than pristine CZS and BTO, respectively. Its enhanced piezo-photocatalytic performance is attributed to the induced piezoelectric effect, sulfur defects, internal electric field, and S-Scheme charge transfer. Scavenger studies identified h + , O 2 - , and • OH as the major reactive species responsible for CIP degradation. After 90 minutes, the extent of mineralization reached 46.7%, and intermediate products were evaluated using Ultra-performance liquid chromatography-mass spectrometry(UPLC-MS), with their toxicity assessed using the Toxicity Estimation Software Tool (T.E.S.T). The catalyst demonstrated excellent stability over four reuse cycles. The successful development of the BTO/CZS heterojunction holds significant promise for advancing environmentally sustainable water treatment and pollution remediation technologies. • BaTiO 3 /Cd 0.5 Zn 0.5 S heterojunction effectively degrades ciprofloxacin in wastewater. • The catalyst outperforms CZS and BTO, with ~85% ciprofloxacin degradation. • Enhanced performance due to piezoelectric effect, sulfur defects, and S-scheme transfer. • Catalyst shows high stability, maintaining efficiency after four reuse cycles.