Boosting solar-driven volatile organic compounds desorption via the synergy of NH2-UiO-66 with hollow polypyrrole nanotube

Metal-organic frameworks (MOFs) are witnessing rapid development in the adsorption removal of volatile organic compounds (VOCs) from polluted air due to their remarkable adsorption capacity. However, their intrinsic poor thermal conductivities often make their regeneration processes suffer from high energy con-sumption. Herein, a novel photodynamic NH2-UiO-66@PPy adsorbent was constructed by in-situ growth of NH2- UiO-66 particles onto hollow PPy nanotubes via a facile solvothermal method. This adsorbent was able to extend the light response range of NH2-UiO-66 from UV-vis to near-infrared region. Benefitting from the superior photothermal conversion ability of PPy and well contact interface between PPy nanotube and its surface-loaded NH2-UiO-66 particles, higher surface temperature of PPy nanotubes would be obtained upon exposure to UV-vis-NIR light and further transferred to its surrounding MOF nanoparticles. Eventually, the surface temperature of the optimal NH2-UiO-66@PPy-2 adsorbent can be as high as 245 degrees C, and almost 100% of the adsorbed ethyl acetate was able to be released within 30 min of UV-vis-NIR irradiation. Distinct from the conventional heating whole adsorbent bed, this photothermal desorption strategy would significantly reduce the heat-transfer among adsorbent particles and become less dependent on the heat-transfer rate, thus efficiently alleviating the intrinsic thermal conductivity shortcoming of MOF.

Automated summary

Metal-organic frameworks (MOFs) are being developed rapidly for the removal of volatile organic compounds (VOCs) due to their high adsorption capacity. However, their poor thermal conductivities hinder efficient regeneration processes. In this study, a novel photodynamic NH2-UiO-66@PPy adsorbent was developed to overcome this issue by growing NH2-UiO-66 particles on PPy nanotubes. This adsorbent demonstrated improved thermal conductivity and efficient desorption of VOCs under UV-vis-NIR irradiation.