Scalable, flexible and hydrophilic porous membrane with single-layered rGO-W18O49 nanoplates dispersion for high-efficiency solar water evaporation

Solar-driven interfacial evaporation has emerged as a prominent sustainable desalination technology due to its clear energy utilization and low operational costs. However, developing evaporators with high efficiency, structural stability, and salt-resistant properties remains a critical challenge. Herein, we designed an rGCW_x@PVDF-PVP membrane fabricated via a facile phase inversion strategy, demonstrating exceptional solar evaporation performance and cyclic stability. The synergistic integration of rGO-xW₁₈O₄₉ nanoplates (W₁₈O₄₉ nanowires anchored on rGO surface) and CNTs enables broadband spectral absorbance (∼90.00%). The hierarchically porous PVDF-PVP membrane facilitates rapid water transport and provides substantial vapor escape channels. Notably, the incorporation of PVP with nitrogen-containing functional groups modulates water molecule interactions by weakening hydrogen bonding networks, and PVP effectively reduces the evaporation enthalpy of the water system and improves evaporation performance. Under 1 sun irradiation, the evaporator achieves an outstanding evaporation rate of 2.09 kg m⁻² h⁻¹ with a photothermal conversion efficiency of 92.80%. Remarkably, the evaporator maintains terrific performance in desalination without surface salt crystallization, demonstrating exceptional anti-fouling capability during prolonged operation. This novel and simple thin-film evaporator presents a broad prospect in the field of interfacial evaporation, offering a practical strategy for sustainable water purification and global freshwater scarcity.