Band-engineered ZnWO4@Ni-BiOCl Z-scheme heterojunction for synergistic visible-light-driven photocatalytic detoxification, attenuation of ecotoxicity, and ultrasensitive electrochemical sensing of tetracycline

Title : Band-engineered ZnWO4@Ni-BiOCl Z-scheme heterojunction for synergistic visible-light-driven photocatalytic detoxification, attenuation of ecotoxicity, and ultrasensitive electrochemical sensing of tetracycline

Abstract:

The rational design of Z-scheme heterojunctions offers a powerful strategy for integrated environmental remediation by coupling pollutant detection with degradation. In this work, we report a hierarchical Z-scheme heterostructure, ZnWO₄@Ni-BiOCl (ZW@Ni-BOC), constructed via in situ anchoring of Ni-doped BiOCl nanoflakes onto ZnWO₄ nanorods. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) confirmed the formation of intimate interfaces, while the optimized 1.5:1 ZW@Ni-BOC exhibited markedly enhanced charge separation, extended visible-light absorption, and a high density of surface-active sites. When integrated on a glassy carbon electrode, ZW@Ni-BOC functioned as an ultrasensitive electrochemical sensing interface for tetracycline (TC), achieving a sensitivity of 11.66 μA μM^-1 cm^-2, a detection limit of 0.66 nM, and broad linear ranges. Simultaneously, the composite demonstrated outstanding photocatalytic efficiency under visible light, enabling rapid degradation of TC, Rhodamine B (RhB), and chlorpyrifos (CPF). Mechanistic studies, including UV–Vis diffuse reflectance spectroscopy, reactive-species trapping, and LC–MS, validated the Z-scheme charge-transfer pathway and revealed the degradation routes of TC. QSAR-based toxicity assessment further confirmed a substantial reduction in ecotoxicity of intermediates, while antibacterial studies showed complete inactivation of S. aureus and E. coli within 60 min under visible-light irradiation. Together, these results highlight ZW@Ni-BOC as a multifunctional nanoplatform that unites pollutant sensing, photocatalytic detoxification, toxicity attenuation, and microbial disinfection, offering a scalable and sustainable route for environmental remediation.

Biography:

Prerna is a doctoral researcher in the Department of Chemistry at Panjab University, Chandigarh. Her work focuses on the design, synthesis, and characterization of nanomaterials, with emphasis on electrochemical detection, environmental remediation, and antimicrobial applications. As a CSIR Research Fellow, she has gained extensive experience with spectroscopic and microscopic techniques while studying structure property relationships in functional materials. She has completed her MSc (Hons.) in Organic Chemistry at Panjab University and presented her work at several national and international meetings. Alongside research, she assists in teaching laboratory courses. Outside the lab, she enjoys sports, travelling, and music.