Fabrication and Modification of Hydrotalcite‐Based Photocatalysts and Their Composites for CO 2 Reduction: A Critical Review

Layered double hydroxides (LDHs), which resemble hydrotalcite, are a type of materials with cationic layers and exchangeable interlayer anions. They have drawn lots of curiosity as a high‐temperature CO2 adsorbent because of its quick desorption/sorption kinetics and renewability. Due to its extensive divalent or trivalent cationic metals, high anion exchange property, memory effect, adjustable behavior, bio‐friendliness, easy to prepare and relatively low cost, the LDHs‐based materials are becoming increasingly popular for photocatalytic CO2 reduction reaction (CO2RR). Fabrication and modification are good ways to move forward the advancement of LDHs‐based catalysts, which will help chemistry and materials science make great progress. In this review we discussed structural characteristics and the methods for preparation and modification of LDHs‐based photocatalysts. We also highlighted and discussed the major developments and applications in photocatalytic CO2RR as well as the photocatalytic mechanism. The goal of the present review is to give a broad summary of the various LDHs‐based photocatalysts and the corresponding design strategies, which could motivate more excellent research works to explore this kind of CO2RR photocatalysts to further increase CO2 conversion yield and selectivity.