Development of biomass aerogels with aligned channels: For continuous treatment of oily wastewater and solar-powered oil evaporation

A biomass CS/CNTs@MTMS (MCCS) aerogel with both aligned channel network, superhydrophobicity, and photothermal conversion ability was prepared by a green and facile strategy of directed freeze-drying and chemical vapor deposition using chitosan (CS), carbon nanotubes (CNTs), and methyltrimethoxysilane (MTMS) as the building materials. Capacity to adsorb a large variety of oils and organic solvents, with an adsorption capacity of up to 34-83 g/g. After 10 cycles, the adsorption capacity of MCCS remained at 94 % of the initial capacity, providing excellent reusability. In addition, due to its unique network of aligned channels, the MCCS can continuously separate oil and water, making it a sustainable oil-water separator. More interestingly, the MCCS aerogel has excellent photothermal conversion capabilities, and it was utilized to evaporate oil collected during the oil-water separation process using solar energy. This work provides an opportunity to design novel self-cleaning photothermally driven oil-water separation biomass materials with superhydrophobicity-strong lipophilicity.