Aminophenol–formaldehyde particles containing hydrophilic benzenoid-amine for a highly efficient solar-thermal water harvester†

Solar-driven interfacial evaporation systems hold great potential for addressing clean water scarcity and wastewater purification challenges. However, low water yield and the presence of contaminants in wastewater remain significant obstacles. This study introduces wide light-absorbing hydrophilic aminophenol–formaldehyde (APF) resin particles with π-conjugated and π-stacked benzenoid–quinoid donor–acceptor couples as light absorbers to enhance solar-to-vapor conversion efficiency. The incorporation of hydrophilic amine groups led to a 30% increase in the evaporation rate and a 32% reduction in the evaporation enthalpy. The carbonized APF-based evaporator achieved a high evaporation rate of 2.89 kg m⁻² h⁻¹ and 3.07 kg m⁻² h⁻¹ from sewage and simulated seawater, respectively, under natural solar irradiance (0.7 suns). Furthermore, solar vapor generation rates reached 16.22 kg m⁻² h⁻¹ and 13.98 kg m⁻² h⁻¹ from sewage and simulated seawater under 3.9 suns. The APF-based evaporator also demonstrated exceptional stability and durability in solar-to-vapor conversion.