Lignin-based superhydrophobic melamine resin sponges and their application in oil/water separation

•Stable construction of micro-nano rough surface structure through HDTMS modified lignin.•SHP-MRSs showed a high efficiency to remove oil from water in continuous process.•The separation efficiency of SHP-MRSs was above 98.6 % for oil/organic solvents.•The efficiency remains above 98 % after 100 cycles of emulsion separation. Exploiting superhydrophobic materials with low-cost, versatility and excellent reusability is still challenging for marine oil spill pollution problem. Here, we develop a superhydrophobic porous material composed of lignin, hexadecyltrimethoxysilane (HDTMS) and melamine resin sponge via simple impregnation. The as-prepared superhydrophobic melamine resin sponges (SHP-MRSs) possesses excellent separation efficiency (>98.6 %) for kinds of oil-water solutions, excellent durability (keep superhydrophobility after 35 cycles of oil-water separation) and high efficiency for oil-water continuous separation property. More interesting, the SHP-MRSs presented outstanding emulsions separation efficiency (>98.7 %) and cycling separation performance as high as 100 times. In addition, the SHP-MRSs exhibited excellent mechanical durability, high selectivity, and acid and alkali resistance. The entire features make the prepared SHP-MRSs a promising oil-water separation material for cut-price and prominent application for oil spill treatment.