For example, a photocatalyst with a composition of (1B 0.1CE 0.06AG) might exhibit a certain band gap energy, which could be lower than that of pure TiO2 due to the presence of B and CE dopants. As the concentration of B is increased to 2B, as in (2B 0.1CE0.06AG), the band gap might further decrease, indicating a stronger interaction between the dopants and the TiO2 lattice.