Polycations inclusion to simultaneously boost permeation and selectivity of two-dimensional TaS2 membranes for acid recovery.

• The micro-chemical environments of TaS 2 laminates were modified for acid recovery. • Positively charged polymers were inserted into TaS 2 channels. • The modified TaS 2 membranes show improving acid fluxes and separation factors synergistically. • The next generation acid recovery membranes were successfully established. Two dimensional (2D) TaS 2 laminates have highly regular and ordered transfer mass channels, thus being promising acid recovery membrane candidates for diffusion dialysis (DD) applications to discern H+ and metallic ions. However, it remains a daunting task to get access to high-performance 2D acid recycling membranes made from single TaS 2 nanosheets. Here, we report manipulation of the chemical environments of TaS 2 channels to develop excellent acid recycling 2D membranes. As demonstration projects, positively charged poly(diallyldimethylammonium chloride) (PDDA) and poly(4-vinylpyridine) (P4VP) in acid solution were chosen as polycation intercalators to modify the TaS 2 2D channels. Under the DD mode, the TaS 2 membrane exhibits a H+ dialysis coefficient (U H +) of 3.72 × 10−3 m h−1 and separation factor (S) of 9 towards the simulated acid pickle. In contrast, the U H + and S value of the PDDA@TaS 2 membrane improve to 12.7 × 10−3 m h−1 and 34.4 respectively. Those of the P4VP@TaS 2 membrane increase to 12.5 × 10−3 m h−1 and 29.1 respectively. The reported acid recovery properties of PDDA@TaS 2 and P4VP@TaS 2 membranes exceed the commercial DF-120 acid recovery membranes. The experiment and simulation results reveal that the synergistical enhancements of U H + and S originate from the incorporating polycations in PDDA@TaS 2 and P4VP@TaS 2 composite channels. [ABSTRACT FROM AUTHOR]