Hierarchical LDH@Ti3C2-based bifunctional evaporator for solar-driven water-electricity cogeneration

Freshwater scarcity and energy shortages pose critical challenges to sustainable development, highlighting the urgent need for integrated solutions. Herein, we report a hierarchical layered double hydroxide LDH@Ti 3 C 2 composite engineered for water evaporation and thermoelectric power generation. The composite was synthesized through a multistep process, where ZIF-67-derived N-doped carbon was etched in situ to form CoMo LDH, which was subsequently assembled with exfoliated Ti 3 C 2 nanosheets via electrostatic interaction. The resulting LDH@Ti 3 C 2 exhibits broadband absorption (96.13%), good photothermal performance, and intrinsic magnetism for facile recovery. When incorporated into an air-laid paper substrate, the integrated evaporator shows 2.09 kg m −2  h −1 of evaporation rate and a solar-to-steam conversion efficiency of 86.3% under 1 sun irradiation, combined with robust stability over repeated cycles. Integrated with thermoelectric modules, simultaneously harvests waste heat, delivering an output power density of 33.7 ± 2.2 mW m −2 and stable performance in multiple cycles. Outdoor testing further demonstrates efficient seawater desalination, dye pollutant removal, and sufficient electricity generation to power small electronic devices. The proposed strategy effectively promotes the practical application of sustainable and multifunctional systems for simultaneous solar water purification and electricity generation.