First-principles investigation of electronic and optical properties of Fe doped in CsBrO3 for enhanced photocatalytic hydrogen production

Abstract

Self-consistent ab initio calculations carried out using full potential augmented plane wave (FP-LAPW) method were performed to study the electronic, optical and photocatalytic properties of CsBrO3 and Fe doped CsBrO3. Ground state and formation energy for CsBrO3-perovskite are calculated and analyzed. The magnetic moment of Cs, Br, Fe and O are calculated in CsBrO3 and CsBr0.34Fe0.66O3. The band structure, total and partial density of states (DOS) diagrams are discussed.The CsBrO3 have semiconductor character with a wide direct gap. The value of gap energy is 4.24 eV of CsBrO3. Fe doped in CsBrO3 lead to band gap narrowing 1.02 eV for spin up and 1.434 eV for spin dn , which enhances the visible light catalytic activity. The conduction band minimum (CBM) and valence band maximum (VBM) potentials vs. normal hydrogen electrode (NHE) are calculated and analyzed. The general profiles of the optical spectra and the optical properties, including the real and imaginary part of dielectric function, reflectivity, absorption and optical conductivity are discussed. Our results predict that Fe doped CsBrO3 is a promising visible light photo-catalyst for hydrogen production by water splitting.