Amidst the growing global energy crisis and environmental degradation, the development of innovative materials that can simultaneously address energy generation and wastewater treatment is crucial[1]. Herein, we have designed a durable, flexible, and reusable composite membrane incorporating chitosan (CHS), one-pot hydrothermally synthesized phosphorene nanosheets (BP), and CTAB-assissted hydrothermally synthesis zirconium oxide (ZO) nanoparticles. This ternary bio-nanocomposite was fabricated using the solvent casting method, and its structural integrity was confirmed through comprehensive characterizations, highlighting the successful integration of polar phases, BP, and ZO. This piezo-responsive membrane demonstrated remarkable energy harvesting capabilities, generating a piezoelectric voltage of 4.1 V and a current of 1.5 μA under the perpendicular flow of water droplets, with a power density of 50 Wm-3. Beyond energy generation, the membrane exhibited superior piezocatalytic activity under ultrasonication, effectively degrading carcinogenic dyes such as methylene blue (MB, 89.93%), Congo red (CR, 99.2%), methyl orange (MO, 82.37%), and a 1:1 MB-CR mixture (76.35%) within 35 minutes. Optimized conditions of alkaline pH, 60 W ultrasonic power, and 2.5 ppm dye concentration further enhanced its degradation efficiency. Field tests demonstrated its practical viability, achieving 96.21% degradation in drinking water and 98.23% in wastewater. Additionally, a water flow-driven piezoelectric catalytic system consumed only 1.2% of the energy required by traditional ultrasonic systems, emphasizing its energy efficiency and scalability for practical applications. Degradation mechanisms were investigated through LC-MS analysis and frontier molecular orbital theory, and reduced ecological toxicity was verified using phytotoxicity assays on tulsi (Ocimum tenuiflorum) plants. The membrane also achieved over 90% degradation of pharmaceutical pollutants like ciprofloxacin and tetracycline within 60 minutes of ultrasonication and displayed over 99% antibacterial activity against both Gram-negative (E.coli) and Gram-positive (E. faecalis). ROS quantification confirmed the synergistic role of BP in enhancing the piezocatalytic performance of the ZO composite membrane compared to membranes with only CHS or CHS-BP. This novel, multifunctional membrane provides a sustainable solution to the dual challenges of energy scarcity and water pollution. Its energy-efficient, scalable design positions it as a promising candidate for large-scale environmental remediation and renewable energy generation.

Indrajit Mondal, a Senior Research Fellow at Jadavpur University, and Member of Royal Society of Chemistry, is currently working toward his Ph.D. in Physics. He completed both his B.Sc. (Hons.) and M.Sc. in Physics at the same institution. His doctoral research, supervised by Prof. Pabitra Kumar Paul and Prof. Sukhen Das, involves synthesizing and characterizing Transition Metal Oxide Nanoparticles (TMONPs) decorated Carbon Nanofibers (CNFs) composites for potential materials science applications. With over 19 publications in reputed international journals , his work has received recognition, including the Wiley Best Poster Award at CMMSP-2024, Best Paper Presentation Award at NCFMSP-2024, Best Paper Certificate (1st position) by Royal Society of Chemistry at ICST-2024,Best poster award by Royal Society of Chemistry at

ETCSTSI-2025, Best Poster Certificate (1st position) at ISDRC-2025, Best Poster & Third Place in Exhibition Category at VIBHA and honors at research conventions by AIU. He holds qualifications in UGC-CSIR NET, GATE, and WBSET and was awarded the DST INSPIRE Fellowship in 2022.