Counter-Intuitive Magneto-Water-Wetting Effect to CO Adsorption at Room Temperature Using MgO/Mg(OH) Nanocomposites.

MgO/Mg(OH)-based materials have been intensively explored for CO adsorption due to their high theoretical but low practical CO capture efficiency. Our previous study on the effect of HO wetting on CO adsorption in MgO/Mg(OH) nanostructures found that the presence of HO molecules significantly increases (decreases) CO adsorption on the MgO (Mg(OH)) surface. Furthermore, the magneto-water-wetting technique is used to improve the CO capture efficiency of various nanofluids by increasing the mass transfer efficiency of nanobeads. However, the influence of magneto-wetting to the CO adsorption at nanobead surfaces remains unknown. The effect of magneto-water-wetting on CO adsorption on MgO/Mg(OH) nanocomposites was investigated experimentally in this study. Contrary to popular belief, magneto-water-wetting does not always increase CO adsorption; in fact, if Mg(OH) dominates in the nanocomposite, it can actually decrease CO adsorption. As a result of our structural research, we hypothesized that the creation of a thin HO layer between nanograins prevents CO from flowing through, hence slowing down CO adsorption during the carbon-hydration aging process. Finally, the magneto-water-wetting technique can be used to control the carbon-hydration process and uncover both novel insights and discoveries of CO capture from air at room temperature to guide the design and development of ferrofluid devices for biomedical and energy applications.