Multidimensional TiO₂ photocatalysts for the degradation of organic dyes in wastewater treatment

The discharge of dye industry wastewater without any proper treatments has raised tremendous concerns due to its hazardous nature and potential risks. Photocatalytic degradation is a promising technology for environmentally friendly and sustainable treatment of dye pollutants. Nanomaterial-based photocatalysts have been successfully applied to treat industrial dye wastewater. Among them, titanium dioxide (TiO₂) with diverse nanostructure and numerous advantages has garnered significant attentions. However, the morphological difference of TiO₂ is of paramount importance for enhancing its degradation performance. This review provides an overview of recent advances in various forms of multidimensional TiO₂, including 0D nanoparticles, 1D nanowires, nanotubes, nanofibers, and nanorods, 2D nanosheets and nanoplates, as well as assembled 3D micro-nano structures, for photocatalytic dye wastewater treatment. The article could briefly elaborate the conventional synthesis routes, advantages, challenges, and application areas of TiO₂ in different dimensions, and compares their photocatalytic degradation performance and mechanisms. Simultaneously, these approaches of modified performances by doping metal ions and non-metal ions have emphatically involved over here. Noteworthily, the insights into the future trends, challenges, and prospects of multidimensional TiO₂ materials have been also proposed.