Oriented 2D metal organic framework coating on bacterial cellulose for nitrobenzene removal from water by filtration

Continuous removal of organic chemicals from water by filtration, either for producing drinking water or mitigating pollution from wastewater, requires the consumption of energy especially when the concentration of pollutant is low. A filtration material or process with higher flux and selectivity would be ideal for such purposes. Water-stable metal-organic frameworks (MOFs) have great potential for in water-treatment, due to their large number of adsorption sites and customizable chemistry. Attaching MOFs to a suitable support is also important to make sure the most possible adsorption sites are exposed and that the utilization of MOF material is high. This work reports an oriented continuous 2-D MOF coating on bacterial cellulose (BC) for removing nitrobenzene from water. Cu(BDC) was chosen because its superior properties for filtration such as: pore size, water stability, morphology. The ultra-thin Cu(BDC) ensure high permeance and rejection with parallel orientation. The optimal parallel orientation of the MOFs on the BC was obtained by controlling the functionalization of the BC support. The 20 nm thick coating reported in this work shows high water permeance (10.85 L/(hr·m²·psi) and high rejection of nitrobenzene (68.6%), which are higher than state-of-the-art polymeric membranes.