A DFT study of optical, elastic, mechanical, and overall water-splitting photocatalytic properties of pristine and Cd substituted BaZrO₃: A lead free environment friendly material

First principle calculations are taken into account to investigate different properties like overall water splitting, elastic, mechanical, optical, electronic, and structural, of pure along with cadmium-induced BaZrO₃ which is an oxide-based perovskite. Ultra-soft pseudo-potential is integrated within Cambridge Serial Total Energy Package to explore these properties. Generalized gradient approximation suggested by Perdew-Burke Erzenhoff and hybrid functional is taken into account for exchange–correlation potential. Cadmium introduced at Ba site is more successful rather than Zirconium as brand new gamma points appeared that also influenced the electronic formation of pure BZO minimized band gap from 3.114–0 eV and 4.203–0.470 eV by using GGA-PBE and HSE03 respectively. In Cd substitution case, Fermi level shifted to near valence band which reveals property of semiconductor material called p-type before showing conducting behavior at full replacement of Ba with Cd. Furthermore, mechanical properties derived from elastic constants i.e. Bulk modulus, Shear modulus, Young modulus, Poisson ratio, and finally these materials were established to justify born stability requirements. In addition, Cauchy's pressure along with Pugh's ratio also proved brittle nature of these material compositions. We explored and compared optical properties for example absorption spectra, refractive index (3.1), dielectric function, and reflectivity, as an energy loss function of pure BZO in comparison with Cd loaded BZO. Cd based BZO transforms optical performance considerably therefore this material is more effective for optoelectronic devices. Overall water splitting was studied for pure and Cd substituted BaZrO₃. The pure and two and Six atoms doped material play a vital role for overall water splitting. It is proposed that the said materials are not only lead free for green energy applications in photocatalytic activity but also that the bandgap range is suitable for solar cell applications.