Recent advances in photocatalytic performances of layered double hydroxides-based materials for VOCs and CO2 mitigation: A comprehensive review

Abstract

The gradual increase of volatile organic compounds (VOCs) and CO₂ create serious environmental and health complications. Therefore, the abatement of VOCs and the conversion of CO₂ into solar chemicals/fuels through photocatalysis technique have been receiving more attention from the research community. Considerable progresses have been made in the development of semiconductor-based photocatalysts, where selecting efficient, economical, stable and environmentally beneficial photocatalysts is crucial. In recent decades, exploring layered double hydroxides (LDHs)-based materials as potential catalysts has become an attractive research topic because LDHs are versatile, adaptable semiconducting materials suitable for heterogeneous catalysis to meet growing demands. In addition to their unique two dimensional (2D) layered structure, exchangeable interlayer anions, adjustable metal composition and tuneable physicochemical, electrical and optical properties, LDHs serve as excellent starting points for developing a variety of bimetallic products through post-synthesis modifications. This review provides an overview of recent advancements in LDHs-based photocatalysts for VOCs abatement and CO₂ reduction. It begins with an overview of LDHs and photocatalytic theory, followed by a discussion of the photooxidation of VOCs and the selection of LDHs and LDHs-based photocatalysts for VOCs abatement. Furthermore, it addresses the environmental and industrial significance of CO₂ reduction, the fundamentals of CO₂ photoreduction, LDHs-based materials (including metal cations and anions tunability, morphology, noble metals, defect engineering and heterogeneous materials) for CO₂ photoreduction, C2+ products formation and achieving efficiency and selectivity in LDHs-based catalysts. Moreover, the stability of LDHs-based heterostructure photocatalysts along with their scalability and associated scientific challenges are discussed. Finally, the review offers new insights into the main obstacles, prospects and perspectives for further study in the developing field. It is evident that innovative LDHs-based materials have the potential to serve as highly effective photocatalysts and potentially lead to significant advances in VOCs and CO₂ photoreduction.