A Lotus‐Petiole‐Inspired Hierarchical Design with Hydrophilic/Hydrophobic Management for Enhanced Solar Water Purification

Abstract

AbstractSolar‐driven vapor generation offers an affordable and sustainable approach to solve global freshwater scarcity. Creating interfacial solar evaporators capable of increasing water production rates matching human water requirements is highly desirable but challenging due to the slow water transportation dynamics and unavoidable oil‐fouling. Herein, a bio‐inspired lotus‐petiole‐mimetic microstructured graphene/poly(N‐acryloyl glycinamide) solar evaporator with integrated hydrophilic and hydrophobic microregions is developed. Through accurate control of the supramolecular interactions, the optimized solar evaporator incorporating unique structural features and wettability shows high light harvesting, enhanced water activation, and reduced energy demand for water vaporization, enabling a groundbreaking comprehensive performance along evaporation rate up to 3.4 kg m−2 h−1 and energy conversion efficiency of ≈93% under one sun irradiation (1 kW m−2). Molecular dynamics simulations reveal that the abundant hydrogen bonding sites of the polymeric networks can thermodynamically modulate the escape behavior of water molecules. Notably, neither decrease in evaporation rate nor fouling on solar evaporators is observed during the prolonged purification process toward nano/submicrometer emulsions, oily brines, actual seawater, and domestic wastewater. This study provides distinctive insights into water evaporation behaviors at a molecular level and pioneers a rational strategy to design high‐yield freshwater‐generation systems for wastewater containing complex contaminants.