Enhancing nanoplastics removal and green hydrogen recovery through photovoltaic-driven hybrid electrochemical treatment of urban treated wastewater

Hybrid electrochemical systems that couple pollutant degradation with green hydrogen (H 2 ) recovery offer a promising pathway toward circular, sustainable wastewater treatment. In this work, a boron-doped diamond (BDD) anode and a Ni Fe stainless-steel (Ni Fe SS) mesh cathode were used, for the first time, to simultaneously degrade polystyrene nanoplastics (PS-NPs) and generate green H 2 in synthetic urban treated wastewater. The electrochemical process was driven by photovoltaic solar panels, achieving up to 92% removal of PS-NPs and 83% total organic carbon (TOC) mineralization in a divided cell, mediated by hydroxyl and persulphate radicals. Green H 2 was continuously produced at the cathode with nearly complete Faradaic efficiency, confirming the efficient conversion of electrical energy into a valuable fuel. Furthermore, it was demonstrated, by differential electrochemical mass spectroscopy (DEMS) analysis, that the anodically treated effluent could be directly reused as the catholyte, achieving comparable performance in producing green H 2 with higher purity while reducing freshwater consumption. These results demonstrate the feasibility of integrating nanoplastics abatement and renewable H 2 generation within a single electrochemical process, advancing toward sustainable water-to-energy technologies. • Hybrid electrochemical process coupling nanoplastics removal and H 2 recovery. • Up to 92% PS-NPs and 83% TOC removal were achieved using the BDD anode-Ni-Fe cathode system. • Continuous H 2 generation with nearly 100% Faradaic efficiency. • Treated effluent reused as catholyte, enhancing sustainability and H 2 purity.