UiO-66 derived etched carbon/polymer membranes: high-performance supports for the extraction of organic pollutants from water

Herein we report the use of the zirconium metal–organic framework (UiO-66) as precursor to prepare porous carbons by a direct carbonization step (carbon-ZrO₂). By applying a post-carbonization acidic etching treatment with hydrofluoric acid (HF), the initial surface area of the carbon-ZrO₂ sample increased from 270 m² g⁻¹ to 1550 m² g⁻¹ (carbon-ZrO₂-HF). This increase is attributed to the partial removal of the ZrO₂ present in the UiO-66-derived carbon. Carbon-ZrO₂-HF exhibited fast adsorption kinetics and an outstanding maximum adsorption capacity of 510 mg g⁻¹ for the dye rhodamine B. For practical applications, the obtained porous carbon-ZrO₂-HF material was used to fabricate a carbon composite membrane using polyvinylidene fluoride. The prepared membranes were applied as water filtration supports for the extraction of toxic phenols from water, including an endocrine disrupting phenol with widespread exposure: bisphenol A. High efficiency for the simultaneous extraction of phenolic pollutants, and an excellent reusability with a variation of a 2% for 10 consecutive bisphenol A extraction cycles, were obtained. Due to their high and accessible porosity, small particles size, and facile processability into membranes, the UiO-66 derived etched carbons are promising materials for environmental applications, such as the extraction of organic toxic pollutants.