Electronic structures and optoelectronic properties of ATiOPO4 (A = H, Li, Na, K, Rb, Cs, Fr, NH4, Ag) compounds and their applications in water splitting, CO2 reduction, and photo-degradation

Abstract

Abstract In this paper, we have presented a computational study on the crystal structures, electronic, and optical properties of the titanyl phosphate family (ATiOPO4, where A = H, Li, Na, K, Rb, Fr, NH4 and Ag). The lattice parameters and bandgaps were calculated with the Perdew-Burke-Ernzerhof (PBE), Revised Perdew-Burke-Ernzerhof (RPBE), Perdew Wang (PW91), Wu-Cohen (WC), and Perdew-Burke-Ernzerhof for solids (PBEsol) non-local functionals of the generalized gradient approximations (GAA). The PBEsol functional provided better results and closer to the experimental data of the ATiOPO4 compounds; and thus, this method was used to analyze the band structures, density of states, and optical properties. A comparison between the optical properties (dielectric function, refractive index, absorption coefficient, reflectivity, electron energy loss spectrum, and photoconductivity) of ATiOPO4 compounds were discussed. The potentials of valance band and conduction band edges were calculated and used to investigate the protentional applications of the ATiOPO4 materials in water splitting, CO2 reduction, and photo-degradation processes. The results obtained in our investigations show that many of the investigated ATiOPO4 semiconductors could be used as effective photocatalysts in these photocatalytic reactions.