Nitrogen-doped biomass carbon aerogel with self-cleaning ability enhanced copper plasmonic effect for solar evaporation

To addressing the freshwater shortage crisis, this research utilizes industrial-grade multi-walled carbon nanotubes (CNTs) as framework, and modifies the upper surface with Cu nanoparticles to form asymmetric structure, thereby constructing biomass aerogel-based 3D Janus solar evaporator (Cu@CNTs-IP). The evaporator attains performance enhancement via triple synergistic mechanism: First, the strong light absorption of CNTs, synergized with the localized surface plasmon resonance (LSPR) of Cu, boosts light-harvesting ability, reaching 98 % visible light absorption and surface temperature increase to 88.4 °C within 300 s. Secondly, the capillary effect of hollow tubular CNTs is helpful for sustain water supply and steady evaporation rate of 1.28 kg m⁻² h⁻¹ under one sun. Most importantly, the Janus structure confers outstanding salt resistance: crystallization deposits not emerge during long-term saltwater evaporation. Meanwhile, due to rised intermediate water (IW) and reduced evaporation enthalpy, the saltwater evaporation rate is 38 %, higher than that of pure water. This work confirms that Cu@CNTs-IP stands as ideal evaporator incorporating efficient photothermal conversion, stable water transport and salt deposition resistance, thus presenting innovative strategy for biomass-based solar desalination.