CO₂ conversion to solar fuels/chemicals is an alluring approach for narrowing critical issues of global warming, environmental pollution, and climate change, caused by excess atmospheric CO₂ concentration. Amongst various CO₂ conversion strategies, photocatalytic CO₂ conversion (PCC) is considered as a promising approach, which utilizes inexpensive sunlight and water with a photocatalyst material. Hence, development of an efficient and a stable photocatalyst is an essential activity for the respective scientific community to upscale the PCC research domain. Until today, metal oxides, such as TiO₂, ZnO, etc., are categorized as standard photocatalysts because of their relative stability, abundant availability and low cost. However, their performance is tethered by limited light absorption and somewhat physical properties. Recently, layered double hydroxides (LDHs) have offered an exciting and efficient way for PCC due to their superb CO₂ adsorption and moderate photocatalytic properties. The LDH based photocatalysts show marvelous physiochemical and electrical properties like high surface area, stability, and excellent conductivity. In the present review article, a summarized survey is portrayed regarding latest development for LDH based photocatalysts with a focus on synthesis strategies employing various photocatalyst materials, influencing parameters and possible mechanism involved in PCC to useful fuels and chemicals like CO, CH₄, CH₃OH, and H₂.

Photocatalytic CO₂ reduction is emerging as an affordable route for abating its ever increasing concentration. For commercial scale applications, many constraints are still required to be addressed. A variety of research areas are explored, such as development of photocatalysts and photoreactors, reaction parameters and conditions, to resolve these bottlenecks. In general, the photocatalyst performance is mostly adjudged in terms of its ability to only produce hydrocarbon products, and other vital parameters such as light source, reaction parameters, and type of photoreactors used are not normally given appropriate attention. This makes a comprehensive comparison of photocatalytic performance quite unrealistic. Hence, probing the photocatalytic performance in terms of apparent quantum yield (AQY) with the consideration of certain process and experimental parameters is a more reasonable and prudent approach. The present brief review portrays the importance and impact of aforementioned parameters in the field of gas phase photocatalytic CO₂ reduction.

Practical implementation of CO₂ photoreduction technologies requires low-cost, highly efficient, and robust photocatalysts. High surface area photocatalysts are notable in that they offer abundant active sites and enhanced light harvesting. Here we summarize the progress in CO₂ photoreduction with respect to synthesis and application of hierarchical nanostructured photocatalysts.