American Journal of Engineering and Applied Sciences

Advancements in Photocatalysis Research

Description

In chemistry, photocatalysis is the acceleration of a photoreaction in the presence of a catalyst. In catalyzed photolysis, light is absorbed by an adsorbed substrate. In photogenerated catalysis, the photocatalytic activity (PCA) depends on the ability of the catalyst to create electron-hole pairs, which generate free radicals (e.g. hydroxyl radicals: OH) able to undergo secondary reactions. Its practical application was made possible by the discovery of water electrolysis by means of titanium dioxide (TiO₂).In some experiments, photons from a the light source is absorbed by the surface of the titanium dioxide disc, exciting electrons within the material. These then react with the water molecules, splitting it into its constituents of hydrogen and oxygen. Chemicals dissolved in the water prevent the formation of oxygen, which would otherwise recombine with the hydrogen. A breakthrough in photocatalysis research occurred in 1972 when Akira Fujishima and Kenichi Honda discovered electrochemical photolysis of water occurring between connected TiO₂ and platinum electrodes, in which ultraviolet light was absorbed by the former electrode and electrons would flow from the platinum electrode (anode; site of oxidation reaction) to the TiO₂ electrode (cathode; site of reduction reaction); with hydrogen production occurring at the cathode. This was one of the first instances in which hydrogen production could come from a clean and cost-effective source, as the majority of hydrogen production back then came - and still, today comes - from natural gas reforming and gasification. In 2017, Chu et al. assessed the future of electrochemical photolysis of water, discussing its major challenge of developing a cost-effective, energy-efficient photoelectrochemical (PEC) tandem cell, which would, "mimic natural photosynthesis".

Although the efficiencies of present titanium dioxide-based photocatalysts are low, the incorporation of carbon-based nanostructures such as carbon nanotubes and metallic nanoparticles have been shown to enhance the efficiency of these photocatalysts.

Oxidation of organic contaminants using magnetic particles that are coated with titanium dioxide nanoparticles and agitated using a magnetic field while being exposed to UV light.

Conversion of carbon dioxide into gaseous hydrocarbons using titanium dioxide in the presence of water. As an efficient absorber in the UV range, titanium dioxide nanoparticles in the anatase and rutile phases are able to generate excitons by promoting electrons across the bandgap. The electrons and holes react with the surrounding water vapor to produce hydroxyl radicals and protons. At present, proposed reaction mechanisms usually suggest the creation of a highly reactive carbon radical from carbon monoxide and carbon dioxide which then reacts with the photogenerated protons to ultimately form methane.

Sterilization of surgical instruments and removal of unwanted fingerprints from sensitive electrical and optical components.

Decomposition of crude oil with TiO₂ nanoparticles: by using titanium dioxide photocatalysts and UV-A radiation from the sun, the hydrocarbons found in crude oil can be turned into H₂O and CO₂.

Decontamination of water with photocatalysis and adsorption: the removal and destruction of organic contaminants in groundwater can be addressed through the impregnation of adsorbents with photoactive catalysts.

Decomposition of polyaromatic hydrocarbons (PAHs). Triethylamine (TEA) was utilized to solvate and extract the polyaromatic hydrocarbons (PAHs) found in crude oil. By solvating these PAHs, TEA can attract the PAHs to itself. Once removed, TiO2 slurries and UV light can photo catalytically degrade the PAHs.

This issue will publish high-quality reviews and research articles. There is no restriction on the length of the papers. Full experimental and methodological details, as applicable, must be provided, and the special issue will be supported by the American Journal of Engineering and Applied Sciences (https://thescipub.com/journals/ajeas). All submissions must adhere to the AJEAS journal's format requirements.

AJEAS is an the open-access peer-reviewed technical journal which publishes original research contributions and is an unparalleled resource for key advances in the field of engineering. Scope of the journal includes, but not limited to, applied physics and applied mathematics, automation and control, biomedical engineering, chemical engineering, civil engineering, computer engineering, computer science, data engineering, and software engineering, earth and environmental engineering, electrical engineering, industrial engineering and operations research, information technology, and informatics, materials science, measurement and metrology, mechanical engineering, medical physics, power engineering, signal processing, and telecommunications. Manuscripts regarding original research proposals and research ideas are highly appreciated. Manuscripts containing summaries and surveys on research cooperation and future projects (as those founded by national governments or others) are likewise appreciated, as they provide interesting information for a broad field of users.

All accepted papers will be published free of charge for authors.

Topics of interest include, but are not limited to:

1. Photocatalysis
2. Hydrogen production
3. Homogeneous photocatalysis
4. Heterogeneous photocatalysis
5. Photocatalytic water splitting
6. Use of titanium dioxide in self-cleaning glass
7. Disinfection of water by supported titanium dioxide photocatalysts
8. Use of titanium dioxide in self-sterilizing photocatalytic coatings
9. Carbon nanotubes
10. Metallic nanoparticles
11. Titanium dioxide nanoparticles
12. UV light

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