where, Eg -band gap energy (eV), -absorption coefficient, h -Planck's constant, -frequency of light, A -constant, n = 4 (for indirect transition). The plot of (αh ) 1/2 versus (h ) energy determines the band gap energy values which is obtained by extrapolation of the linear portion of the curve to the x-axis. Relative to the band gap energy value of TiO2 (3.4 eV) . For TiO2, which has a well-established band gap energy of approximately 3.4 eV, the DRS analysis of the doped photocatalysts allows for a comparative assessment of how doping influences their electronic structure and light absorption characteristics. This information is crucial for optimizing the photocatalytic efficiency of the synthesized materials, as variations in band gap energy can significantly affect their performance under different light conditions. The diffuse reflectance spectroscopy (DRS) analysis conducted on the synthesized photocatalysts provided valuable insights into their optical properties and band gap energies. The DRS spectra revealed that the band gap values for the photocatalysts, specifically B-TiO2, Ag-TiO2, and Ce-TiO2, ranged from 2.4 to 2.7 eV. This reduction in band gap compared to pure TiO2 (approximately 3.2-3.4 eV) indicates the successful incorporation of dopants, which introduces new energy levels within the band structure.