**3. Gamma rays-induced optical effects in titanium dioxide materials**

Gamma rays, as a form of high-energy electromagnetic radiation, can cause substantial changes in the optical properties of titanium dioxide (TiO2) materials, which serve as a highly adaptable and commonly employed semiconductor [4]. Interaction between titanium dioxide (TiO2) materials with gamma rays has been known to elevate photocatalytic properties, amend electronic structures, and lead to the formation of defects [5]. This section will analyze the different optical impacts caused by gamma rays in TiO2 materials, cite examples, and debate prior experimental findings.

In their study, Bouregui et al. [16] explored the effect of gamma irradiation on TiO2 thin films' optical properties. By examining how different doses of gamma radiation affected these properties, they found that the absorption edge shifted toward lower energies, indicating a decrease in bandgap energy. This change could be due to defects produced by gamma irradiation, which increase the number of defect states and enhance visible light absorption. Along with an increase in photocatalytic efficiency, Bouregui et al. [16] suggest that gamma irradiation may be a valuable technique for tailoring TiO2 thin films' optical properties to meet specific application needs.

The TiO2 lattice can experience defects and oxygen vacancies when gamma rays disrupt the Ti-O bonds [16]. This, in turn, leads to an increased degree of defect states, decreased amount of energy in the bandgap, and a subsequent reinforcement of visible light usage [4]. This process can significantly amplify the photocatalytic efficiency of the TiO2 materials. Wang and colleagues [17] found that by diminishing the energy in the bandgap of gamma-irradiated TiO2 from 3.2 to 2.9 eV, there was a higher degree of photocatalytic activity for the breakdown of organic pollutants.

Several other investigations have reported related findings, supporting the influence of gamma rays on the optical properties of TiO2. In one study by Zuo et al. [18], gamma-irradiated TiO2 nanoparticles were perceived to demonstrate amplified photocatalytic activity in the degradation of organic pollutant under visible light. The enhancement was credited to a reduction in the bandgap and an escalation in oxygen vacancies induced by gamma irradiation. Furthermore, another study by Kumar et al. [19] observed a decline in the bandgap energy and improved photocatalytic activity of TiO2 nanoparticles following exposure to gamma rays, which they attributed to the creation of oxygen vacancies and other defects.

Furthermore, along with photocatalytic applications, gamma-irradiated TiO2 materials seem to have the potential for solar energy conversion. TiO2-based solar cells can benefit from the reduced bandgap energy and increased visible light absorption. A good example is the improvement in photovoltaic performance shown by gamma-irradiated TiO2 nanotubes as reported by Choi et al. [20], which was due to the increase in visible light absorption and the gamma ray-induced modification of electronic structures.

In summary, TiO2 materials can undergo significant alterations in their optical properties, which can improve visible light absorption and photocatalytic efficiency when exposed to gamma rays. Numerous studies have highlighted the potential of gamma-irradiated TiO2 in areas like environmental remediation and solar energy conversion [16]. This is possible since the interaction between gamma rays and TiO2 can produce defects, modify the electronic structures, and improve the photocatalytic properties. Subsequently, researchers should focus on refining the gamma irradiation protocol to achieve the optimal optical properties to enhance the applications of TiO2 [14]. Hybrid materials are also an area of interest. Through the use of semiconductors or metal nanoparticles in conjunction with TiO2, researchers can enhance the separation of photogenerated charge carriers, resulting in improved photocatalytic performance [21]. In hybrid systems, gamma-irradiated TiO2 can be beneficial owing to the changes in optical properties resulting from gamma rays.

Research on gamma rays-generated optical outcomes in titanium dioxide materials has unraveled multiple remarkable phenomena that could be utilized to boost the efficiency of TiO2 in diverse roles. Through comprehending the processes that underpin these outcomes and refining the gamma irradiation procedure, experts can forge fresh methods to engineer sublime TiO2 materials boasting specific optical traits.

*DOI: http://dx.doi.org/10.5772/intechopen.111718 Effects of Gamma Radiation on the Structural, Optical, and Photocatalytic Properties of TiO2…*

This research domain is ripe with prospects for novel inventions and the generation of eco-friendly and better-performing resolutions in environmental revitalization, photovoltaic transformation, and other domains.
