Recent advances in the design and surface modification of titanium-based LDH for photocatalytic applications

Due to their distinctive physical and chemical characteristics, two-dimensional semiconductor heterostructures of titanium-based layered double hydroxide (LDH) materials have appeared as potential photocatalysts for the degradation of dyes. LDH materials have several benefits, including morphological versatility, unique structural features, brucite light structure, ion exchange capabilities, homogenous metal cation distributions, and anion intercalation in interlayers. In particular, however, the photocatalytic activity of titanium-based LDH materials towards organic dyes would be limited because of the quick recombination of charges and inactivation under visible light (only 4% active in visible light). Therefore, in this study, we will summarize the current developments in surface modification of Ti-based LDHs for photocatalytic decomposition of contaminants in aqueous solutions. The typical synthesis techniques, namely the in-situ hydrothermal method, ion exchange method, and coprecipitation method will be highlighted. The surface modification of those materials by metals, metallic oxides, and other inorganic materials and their impacts on photocatalytic behavior will be discussed in terms of a specific area, energy band gap, pore size, porosity level, and Schottky barriers. Additionally, the photocatalytic mechanisms and absorption capacities, as well as future aspects of titanium-based LDH catalysts will be outlined.