Fabrication of Zn-MOF/ZnO nanocomposites for room temperature H2S removal: Adsorption, regeneration, and mechanism. (July 2021) - Gupta, Nishesh Kumar
Abstract: Zn-MOF/ZnO nanocomposites with different organic linkers were fabricated by a rapid ultrasonication method using freshly prepared Zn(OH)2 precipitate. The high metal-to-ligand ratio led to the simultaneous formation of MOFs and ZnO nanoparticles in the MOFs. The surface area was in the range of 12–21 m 2 g −1 . The nanocomposites were tested for H2 S adsorption at room temperature, where the maximum adsorption capacity of 14.2 mg g −1 was recorded for ZnBTC/ZnO in dry conditions. The spent adsorbents were regenerated using methanol and UV irradiation as individual and combined strategies. The successive effect of methanol and UV radiation led to an increased adsorption capacity in the second cycle. The spectroscopic investigation of spent ZnBDC/ZnO confirmed the chemisorption of H2 S over Zn-sites via Zn 2+ −S 2− interaction. The XPS analysis of regenerated ZnBDC/ZnO confirmed a decreased sulfur content and decreased Zn ionic character. The regeneration work in this study is one of the first attempts and could be extrapolated to well-studied Zn-MOFs like MOF-5 for the desulfurization process. Highlights: Rapid fabrication of Zn-MOF/ZnO nanocomposites by ultrasonication method. The maximum adsorption capacity of 14.2 mg g −1 for ZnBTC/ZnO. Chemisorption of H2 S over Zn-sites via Zn 2+ −S 2− interaction. Successful regeneration of spent nanocomposite by methanol and UV irradiation.