Modulation of electronic structures in N‐doped TiO2(B) for hydrogen evolution: A density functional theory study

N‐doping is an effective technique for enhancing the exploitation of TiO2 under visible light, thanks to the level of doping introduced. It is also important to explore N‐doping in the metastable polymorph TiO2(B), which is renowned for its applications in energy materials. In order to investigate the impact of N‐doping on the optical properties of TiO2(B), a systematic comparison of the electronic structural and optical properties of pure and N‐doped TiO2(B) was conducted using density function theory (DFT) calculations. The results indicate that N‐doping is more thermodynamically favorable at the O site with four coordinated atoms. Upon N‐doping, impurity states emerged within the bandgap of TiO2(B), leading to a significant reduction in the energy gap. Consequently, N‐doping primarily enhances the absorbance of visible light, which is crucial for photocatalysis. Furthermore, the adsorption energy of H at the (0 0 1) surface of N‐doped TiO2(B) decreased by 2.75 eV, providing valuable insight for the design of TiO2(B) with exceptional photo‐ and electro‐catalytic performance. To investigate a novel approach for enhancing the catalytic efficiency of TiO2(B), a comprehensive analysis of N doping on TiO2(B) was conducted through density function theory (DFT) calculations. The study encompassed the assessment of formation energy, density of states, and H adsorption energies to determine the optimal doping quantity and placement. We firmly believe that this research will contribute to a deeper understanding of the electron structures of N‐doped TiO2(B) and offer valuable insights for the design of N‐TiO2(B) with improved catalytic applications.