Superhydrophilic and Oleophobic Porous Architectures Based on Basalt Fibers as Oil-Repellent Photothermal Materials for Solar Steam Generation

The construction of efficient solar steam generation systems is of great importance for a range of purposes, such as desalination, distillation, and sterilization. In this study, superhydrophilic and oleophobic porous architectures are prepared by carbonization of a mixture of basalt fibers and tissue paper (BFT) followed by an oleophobic modification (O-BFT) to form oil-repellent photothermal materials for efficient solar steam generation. The as-prepared O-BFT shows high porosity, superior light absorption, and good thermal insulation (thermal conductivity=0.371 Wm(-1) K-1). Correspondingly, a high solar energy conversion efficiency of 90 % is achieved with 1 sun irradiation. Its strong oleophobic wettability endows it with excellent oil-repellent ability. Therefore, a high energy conversion efficiency of 81 % in oily water was obtained with 1 sun irradiation, whereas the unmodified BFT only shows a low energy conversion efficiency of 26 % because of severe oil contamination, which significantly blocks water evaporation. These unique features of O-BFT makes enable efficient solar steam generation even in oily wastewater, showing great advantages over reported photothermal materials that display poor antifouling performance, which in turn largely extends its application range for practical solar steam generation.