Theoretical Study of Cubic Boron Nitride Nanoparticles for Photocatalytic and Catalytic Applications

Cubic boron nitride (c‐BN) is a promising catalyst or catalyst substrate with good thermal, chemical, and mechanical stability. However, the large bandgap ( E g ) limits its photocatalytic activity under visible light, but it is able to work in the UV region or can be used as a composite with other narrow E g semiconductors. In this theoretical study, we investigate the structural, electronic, optical, and thermodynamic properties of c‐BN nanoparticles using density functional theory (DFT) calculations within the CASTEP and Dmol 3 frameworks. The computed Raman, FTIR, and XRD spectra confirm a cubic zinc‐blende‐like structure of c‐BN. Electronic structure calculations using generalized gradient approximations (GGA), B 3 LYP, and HSE06 functionals show a direct bandgap of 4.533 eV (GGA/PBE), 4.381 eV (B 3 LYP), and 4.507 eV (HSE06), consistent with UV‐limited absorption, and illustrate its limited visible‐light absorption. Density of states and electron localization function analyses highlight the polar covalent B─N bonding and charge distribution, revealing that boron p‐orbital states are dominant in the conduction band (CB) while nitrogen p‐orbital states are mostly available in the valance band (VB), and this inequality of state distribution makes B atoms good electron acceptors and N atoms good donors during the catalysis process. Thermodynamic properties also indicate thermal stability and suitability for high‐temperature catalysis. Phonon dispersion analysis also confirms dynamical stability, with no imaginary frequencies. Optical property analysis shows a broad and intense absorption peak, high dielectric response, and low reflectivity, which suggests a favorable electron–hole separation. A wide band edge alignment of c‐BN relative to water redox potentials suggests that c‐BN can drive the generation of reactive oxygen species, which support its potential in photocatalysis, such as water splitting and pollutant degradation.