Hierarchical Flexible Ceramic Nanofiber Membrane for Simultaneous Membrane Distillation and Photocatalytic Hydrogen Evolution.

Abstract

The escalating demand for clean energy and freshwater necessitates integrated rather than compartmentalized technological solutions. However, conventional desalination and photocatalytic hydrogen production typically operate as disparate processes, resulting in suboptimal solar energy utilization and increased system complexity. Herein, a hierarchical and flexible ceramic nanofiber membrane is engineered to fundamentally couple photocatalytic hydrogen evolution with thermally assisted membrane distillation, enabling the simultaneous generation of freshwater and hydrogen. The La-doped ZrO₂ nanofiber scaffold imparts exceptional mechanical robustness and irradiation stability, while in situ-constructed superhydrophobic UiO-66-NH₂/CdS heterojunctions facilitate highly efficient light harvesting, directed charge separation, and durable anti-wetting performance. Consequently, the integrated membrane concurrently delivers an outstanding hydrogen evolution rate of 74.8 mmol m^-2 h^-1 and a sustainable vapor flux of 41.0 L m^-2 h^-1 with 99.95% salt rejection under simulated solar irradiation. Photoelectrochemical measurements and density functional theory calculations elucidate that the configured type-II heterojunction intrinsically drives spatial charge separation to boost proton reduction. Furthermore, multiphysics simulations demonstrate that the three-dimensional fibrous architecture remarkably amplifies light confinement and accelerates rapid gas-product transport, fundamentally mitigating mass transfer limitations. By synergizing structural resilience with unified processes, this work establishes a scalable materials paradigm for high-efficiency water-energy co-generation.