Carbon nanotubes@fly ash Janus composite membrane prepared from fly ash and waste plastics for efficient solar membrane distillation

Janus membranes have attracted many attentions due to their unique and excellent properties endowed by their asymmetric structure and chemical composition. In this study, a novel carbon nanotubes (CNTs)@fly ash Janus composite membrane with hierarchically oriented straight pores, prepared in two steps using industrial solid waste fly ash and white pollutant waste plastic as raw materials, is introduced into the field of solar membrane distillation. The fly ash membrane is fabricated by the combined phase tape inversion casting and sintering method, and CNTs are then in-situ grown on one side of the as-sintered fly ash membrane via the chemical vapor deposition technique to form [email protected] ash Janus membrane. The as-prepared Janus inorganic membrane exhibits good hydrophobicity with a contact angle of 133° as well as excellent gas permeability of 0.51 ± 0.01 × 107 L m−2 h−1 bar−1. When this membrane is used for solar membrane distillation, its interfacial evaporation rate can reach to 1.94 ± 0.01 kg m−2h−1 under one solar intensity, which is 2.19 times that of traditional natural evaporation. Coupled with its lower cost and environmental benefits, this novel Janus membrane is a potential hydrophobic separation membrane to achieve near-zero solid waste emission and efficient seawater desalination.