Janus membrane for simultaneous water purification and power generation

The intricate water-energy nexus pinpoints the necessity of simultaneously managing both resources. The effective interaction between water movement and porous materials lies at the heart of membrane processes as well as hydrovoltaic technology. Herein, an innovative water-energy cogeneration system combining hydrovoltaic technology into membrane distillation processes is reported, leveraging hierarchically porous structures composed of polyaniline (PANI) and polydopamine (PDA)-modified carbon nanotubes (CNTs) nanofilaments on a commercial PVDF substrate. The heat-conductive CNTs network with the water-rich PDA, improves thermal efficiency, enhancing water production by 17.3% compared to bare PVDF. Synergistically enhanced by efficient ion transport within the PANI network, electron accumulation along the PANI-PDA-CNTs direction, and the conductive nanobridge effect of CNTs, a continuous and durable power density of 2.78 µW cm⁻² is achieved in the commercially available membrane filtration process. This work provides an accessible approach to concurrently addressing water and energy challenges.