Integration of Bi2WO6 nanoparticles onto SrTiO3 microflowers for efficient solar light-driven photocatalytic cefixime degradation and hexavalent chromium reduction

The relentless encroachment of pharmaceutical pollutants and toxic heavy metals into aquatic ecosystems has sparked a mounting environmental crisis of unprecedented magnitude that calls for swift and innovative solutions. In response to this escalating calamity, this study embarks on the synthesis of an advanced Z-scheme SrTiO3/Bi2WO6 (STBW) heterojunction composite via a facile solvothermal approach. Employing an arsenal of advanced characterization tools, this research deciphered the seamless synergy between SrTiO3 and Bi2WO6, bringing to light enhanced optoelectronic attributes that drive the exceptional performance of the composite. The photoactivities of STBW composites were meticulously evaluated over their capacities to obliterate CFX and Cr (VI) under simulated solar irradiation. Among the materials tested, the STBW20 composite ascended as the frontrunner, achieving 71.5 % CFX degradation and 73.2 % Cr(VI) reduction. The Z-scheme heterojunction mechanism proved to be the linchpin of this process, as it optimally orchestrated charge carrier migration and drastically curtailed electron-hole recombination, thereby amplifying the overall photocatalytic activity. Moreover, the STBW20 composite demonstrated good reusability and adaptability, effectively delivering high efficacy across several consecutive cycles and various water media, including deionized water, tap water, lake water and aquaculture wastewater. Complementing these findings, phytotoxicity analysis of the treated wastewater via Vigna radiata revealed a monumental reduction in toxicity, further affirming the dual-action efficiency of the STBW20 composite in eradicating contaminants while safeguarding environmental health. This research work is beneficial in designing an efficient composite photocatalyst with Z-scheme heterojunction for the simultaneous elimination of pharmaceutical pollutants and heavy metals from complex wastewater systems.