Recent Developments in Environmental Photocatalytic Degradation of Organic Pollutants: The Case of Titanium Dioxide Nanoparticles—A Review

Abstract

The presence of both organic and inorganic pollutants in water due to industrial, agricultural, and domestic activities has led to the global need for the development of new, improved, and advanced but effective technologies to effectively address the challenges of water quality. It is therefore necessary to develop a technology which would completely remove contaminants from contaminated waters. TiO2(titania) nanocatalysts have a proven potential to treat “difficult-to-remove” contaminants and thus are expected to play an important role in the remediation of environmental and pollution challenges. Titania nanoparticles are intended to be both supplementary and complementary to the present water-treatment technologies through the destruction or transformation of hazardous chemical wastes to innocuous end-products, that is, CO2and H2O. This paper therefore explores and summarizes recent efforts in the area of titania nanoparticle synthesis, modifications, and application of titania nanoparticles for water treatment purposes.

Facile Synthesis of Graphene Oxide-Nano Titania Composites and Evaluation for Visible Light Assisted Photocatalytic Degradation of Rhodamine B

“…Enhanced visible light absorption indicates a strong chemical interaction between titanium ions and oxygen moieties in graphene oxide particles. These results were in close agreement with reported works [1,6].…”

“…Hydrothermally prepared TiO2/GO sheets and their photocatalytic activity for hydrogen evolution from water was also reported [6]. Unlike these reports, the present work reports synthesis of a novel combination of graphene oxide-nano titania composite materials by one step organic solvent free controlled hydrolysis of TiCl4 by maintaining 1:50 volume ratio of TiCl4/H2O in the dispersion of aqueous solution of graphene oxide under ultrasonication.…”

“…However, there are few snagging issues with this material due to rapid electron-hole recombination in 10 -9 s which results in low quantum efficiency, a wide band gap of 3.2 eV limiting its usage mostly in the UV region [5]. Developing a heterogeneous photocatalyst to bring the usage of titania particles in the visible region is a conventional route to enhance the photocatalytic degradation of organic dyes like anionic doping with C, N and S ions or transition metal ions or formation of nano-composites with suitable materials to yield high surface to volume ratio [6,7]. Efforts have been made to synthesize titania-gold nano composites, CdS/CdSe-titania hybrids, etc.…”

Recent Advances in Graphene Based TiO2 Nanocomposites (GTiO2Ns) for Photocatalytic Degradation of Synthetic Dyes

“…In the presence of a contaminant organic molecule (M), adsorbed on the catalyst surface, the • OH radical is the primary oxidant that reacts to produce adducts, followed by the fragmentation of the molecular structure into several intermediates species until the total mineralization of contaminant is completed with the formation of CO 2 and H 2 O [136][137][138].…”

Effect of Concentration of Glycine Surfactant on Photocatalytic Properties of Zinc Oxide Nanoparticles for Photocatalytic Degradation of Methylene Blue

“…Most of the pollutants are organic materials existing in wastewater from factories containing dyes and other toxins. By the discovery of photocatalysis [1], a tremendous work was offered to use semiconductor photocatalysts to destruct organic materials produced in wastewater [2][3][4][5]. The use of metal oxide semiconductors like TiO2 or ZnO photocatalyst for degradation of organic pollutants were severely studied in last decades [6,7].…”