Hydrothermal synthesis of high surface area magnesium oxide (MgO) using ionic surfactant and their capacity as CO2 adsorbent

Abstract

Carbon dioxide (CO₂) is a significant greenhouse gas primarily produced by human activity. The increasing concentration of CO₂ in the atmosphere causes extensive environmental damage, contributing to unpredictable climate change. In this study, we report on the synthesis of high surface area magnesium oxide (MgO) via a hydrothermal method with various surfactants: cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polysorbate 60 (Tween-60). Their capacity as CO₂ adsorbents at low temperatures was observed. The result showed that surfactant-assisted MgO exhibited a high surface area and well-defined morphology, which are more active sites for CO₂ adsorption. The MgO-CTAB demonstrated the highest surface area of 188 m²/g with a CO₂ uptake of 1.13 mmol/g. This improved adsorption capacity is attributed to modification achieved through surfactant assistance. This work highlights the effectiveness of surfactant-assisted synthesis in creating MgO nanoparticles with enhanced CO₂ adsorption at low temperatures, positioning them as promising candidates for low-energy CO₂ capture.