Photocatalysis

What is photocatalysis?

Photocatalysis is the acceleration of a chemical reaction by light. Specifically, light activates a material to start chemical reactions. Usually, titanium dioxide is being used for the material. When light hits catalytic semiconductor particles, it creates pairs of charged particles, kicking off reactions with nearby molecules. This process can clean up pollution, split water to make hydrogen and help with making different chemicals.

How can photocatalysis be utilized?

Furthermore, cleaning wastewater, sterilizing surfaces in hospitals, or making fuel from water using sunlight. Semiconductors' electrical structure makes them “photoredox” process sensitizers. At this point, “photoredox” means the methodology where light is used to alter the redox properties of compounds then accelerating chemical reactions by electron transfer between a photocatalyst and a substrate. Certain semiconductors have the ability to photocatalyze the total mineralization of various organic pollutants, including surfactants, halo hydrocarbons, insecticides, and pesticides. These light-triggered reactions also help useful chemicals and medicines.

Photocatalysis as 3D printing

Mixing photocatalytic particles into 3D printing materials opens up new possibilities. It allows the making of materials that react to light, giving control over properties and patterns. Also, photocatalysis helps with improving the strength and chemistry of printed objects after they're made.

Mechanism

Photocatalysis in 3D printing utilizes a photocatalyst like titanium dioxide mixed with a photosensitive resin. When exposed to light, the photocatalyst triggers reactions in the resin, leading to its solidification layer by layer. This controlled process allows for the creation of detailed structures with excellent precision. Additional steps, such as washing and post-processing, may be necessary to finalize the product.

Potential use of photocatalysis

Photocatalysis has potential in medicine, electronics, and making chemicals. Imagine implants that fight infections, electronic gadgets that respond to light, or making chemicals without harming the environment. Moreover, Various types of organic pollutants can be broken down or converted into intermediate substances or harmless carbon dioxide (CO2) and water (H2O) through Advanced Oxidation Processes (AOPs) and photocatalysis. Titanium dioxide (TiO2) photocatalysis, specifically, is highly effective in oxidizing organic pollutants using reactive oxygen species, without generating harmful byproducts. Therefore, AOPs and photocatalysis show promise for treating dangerous waste or wastewater resulting from the treatment of hazardous wastes.

The future of photocatalysis

As we learn more about photocatalysis, we'll get better at making materials and devices. Photocatalysis is being used for applications to nanomaterials, leading to the development of nanotechnology. In practical applications, photocatalysis is mostly used to address CO2 conversion, water splitting, and pollution removal. Also, collaborations between different fields will speed up progress and increase availability.

References https://www.sciencedirect.com/science/article/abs/pii/S2468606922001587 https://www.sciencedirect.com/science/article/pii/S2352940723001014 https://www.azom.com/news.aspx?newsID=59613 https://www.mdpi.com/2073-4344/3/1/189 https://chemistrydocs.com/photocatalysis-types-mechanism-and-applications/ https://medlineplus.gov/medicines.html https://www.sciencedirect.com/topics/earth-and-planetary-sciences/photocatalysis

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