Experimental and DFT study on the adsorption of VOCs on activated carbon/metal oxides composites

To enhance the interfacial interaction of activated carbon (AC) with volatile organic compounds (VOCs), the AC surface was modified by depositing metal oxide nanoparticles via an evaporation-induced self-assembly (EISA) method. Taking acetone, toluene and methanol as adsorbates, both dynamic and static VOCs adsorption methods were used to evaluate the adsorption performance of AC and AC/MOx (M = Mg, Zn, Cu and Zr). Compared to pure AC, metal oxide nanoparticles deposition effectively increased the adsorption capacity for acetone and methanol, and AC/ZnO composites showed the best adsorption performance for acetone (415 mg g−1) and methanol (481 mg g−1). In concert with the experiment, a set of systematic theoretical calculations, regarding adsorption energy, adsorption equilibrium distance and charge transfer, were performed to explore the VOCs adsorption mechanism on the metal oxide surface. The adsorption performance can be determined by the Lewis acid-base properties of VOCs-metal oxide systems, the characteristic functional groups and the molecular polarity of VOCs molecules, which paves a new way to develop a novel metal oxide based adsorbent for the VOCs adsorption applications.