Carbon foam derived from co-carbonization of lignin and petroleum asphalt for high-efficiency solar evaporators

Abstract

Based on the current low-value applications of petroleum asphalt and the challenges of complex preparation processes and insufficient compressive strength of lignin-based foam carbon materials, a high-performance solar interfacial evaporator (CF2) fabricated through the co-carbonization of lignin and petroleum asphalt is presented. This process exhibits a hierarchically porous carbon foam characterized by low thermal conductivity (0.093 W m⁻¹ K⁻¹), outstanding light absorption characteristics (93.31%) and exceptional compressive strength (10.62 MPa). Under 1 standard sunlight, the evaporator achieved a water evaporation rate of 2.04 kg m⁻² h⁻¹ with an evaporation efficiency of 90.59%. During 11 consecutive hours of outdoor desalination testing, CF2 demonstrated inherent salt tolerance, with no crystallization observed on the surface, while producing freshwater that meets WHO standards. This study introduces a novel methodology for developing high-performance, stable materials specifically tailored for interfacial solar desalination applications.