Buried‐Interface Engineering for Ultrafast Construction of All‐Carbon Fabric Toward Synergistic Water‐Electricity Cogeneration

ABSTRACT Solar‐driven cogeneration of freshwater and electricity addresses global water‐energy challenges but is hindered by complex fabrication and inefficient energy utilization. Herein, we propose a buried‐interface engineering strategy to ultrafast construct an all‐carbon fabric evaporator through a straightforward solution immersion process (<10 min), which is enabled by an O 2 plasma pretreatment that creates a superhydrophilic and oxygen‐functionalized buried interface on carbon cloth. The activated interface imparts a high surface charge and directs dense graphene nanosheets adsorption, forming a continuous network that provides abundant nanoconfined channels and enhanced electrical conductivity. The resulting hierarchical device delivers an evaporation rate of 2.62 kg m −2 h −1 with robust salt rejection and cycling stability, a solar‐to‐vapor conversion efficiency of 159.5%, and an evaporation‐driven power density of 50.03 µW cm −2 . These achievements originate from the synergistic effects of the buried interface, which collectively enable efficient light absorption, rapid water transport, high zeta potential, effective electrical double layer overlap, and superior bulk conductivity. Outdoor experiments validate the durability of the cogeneration system, producing freshwater at ∼11.7 L m −2 day −1 while maintaining stable electricity generation. This work establishes a feasible and ultrafast strategy for constructing high‐performance cogeneration architectures, demonstrating the universal potential of buried‐interface engineering for scalable and sustainable water‐energy solutions.