Polypyrrole@TiO₂ Composite Nanotube System with Enhanced Capillary Fluid and Charge Transfer for High‐Current Hydrovoltaic Energy Generation and Seawater Purification

Abstract

Abstract Harnessing the energy generated from the evaporation of water has received considerable research attention in materials science; however, challenges such as poor conversion efficiency and low current output persist. Herein, an innovative synergistic material system based on titanium dioxide nanotubes coated with polypyrrole (PPy@TiO 2 NTs) is introduced for the simultaneous production of electricity and clean water from solar energy and seawater. The tubular structure of PPy@TiO 2 NT and the molecular interactions between TiO 2 and PPy produce enhanced charge transfer, thereby providing the advantages of the hydrovoltaic effect, solar‐driven water evaporation (SWE), and photocatalysis. Consequently, PPy@TiO 2 NT‐loaded melamine foam can produce tens or more than a hundred microamperes of current in water of various salinities, which is an order of magnitude improvement over previously reported hydrovoltaic evaporation systems. In addition, under 1 sun irradiation, the system achieved an SWE rate of 2.13 kg m −2 h −1 and a methylene blue removal rate of more than 90% within 2 h. The proposed material system, featuring high electrical output and outstanding dual‐mechanism water treatment capabilities, shows high potential for synergistically harnessing solar energy and seawater, as well as for environmental management.