Aramid nanofibers/biochar nanosheets co-assembled composites for wastewater remediation under harsh environments

Nanoscale biochar is a promising material for the remediation of polluted water due to its low-cost sustainability, nevertheless, which still hindered by the self-aggregation and vulnerability issues in actual wastewater. In this work, biochar nanosheets (BCN) were successfully molded into membranes and aerogels with the help of aramid nanofibers (ANF) through a co-assembled process. Ascribing to the improved molecular sieving effects and electrostatic interactions of co-assembled membranes, as well as the superior chemical and thermal stabilities, the resultant ANF/BCNx membranes exhibited favorable dye separation performances toward rhodamine 6 G (R6G) even under high-temperature (e.g.,-96.1 L & sdot;m- 2 & sdot;h-1 & sdot;bar- 1 and-97.4% at 80 degrees C) and strong acidic conditions (e.g.,-84.1 L & sdot;m- 2 & sdot;h-1 & sdot;bar- 1 and-97.9% for 10 wt% H2SO4 solutions). Besides, due to the reduced vaporization enthalpy, the ANF/BCNx aerogels as solar steam generators also demonstrated promising capability for clean water production even in 5 wt% H2SO4 solutions (an evaporation rate of-1.0 kg & sdot;m- 2 & sdot;h-1 and an impressive efficiency of-89.9% under one sun illumination). Compared to conventional biochar materials, this work offered simple feasible morphology engineering designs to prepare multifunctional biochar-based com-posites with unique co-assemble structures, while also demonstrated great potential in wastewater remediation under extreme conditions.