A review on strategies to LDH-based materials to improve adsorption capacity and photoreduction efficiency for CO2

There has been increasing demand for the fixation of CO2 because the increasing atmospheric concentration of CO2 causes the global warming. Layered double hydroxides (LDHs), known as hydrotalcite-like compounds or ionic lamellar compounds, have attracted increasing research interest because of their promising applications as CO2 adsorbents and photocatalysts. The development of LDH-based materials used as CO2 adsorbents and photocatalysts has been separately reviewed in previous papers. However, few of these reviews include the typical synthesis and modification strategies of LDHs to improve their adsorption capacities and photoreduction efficiencies for CO2. Therefore, in this review we summarized some recent progress made in this field. The co-precipitation method is a simple and rapid method for fabricating the desired LDHs directly, and this synthesis method is readily scaled up for industrial production. A few methods have been used for LDHs modification, including doping LDHs with alkali metal, controlling particle characteristics, and fabrication of junctions. It is evident from the literature survey presented herein that modified LDH-based materials have exhibited good potential for the adsorption and photoreduction of CO2. The unresolved issues and possible improvements of LDHs are also highlighted.