Enhanced photocatalysis activity of doped magnetic semiconductor (Rh/Ir):CdS by improving charge-carrier transfer mechanism

Abstract

Photocatalytic splitting of water for the production of hydrogen is one of the emerging research routes in recent years. In this paper, we have performed a spin-polarized calculation to explore the effect of doping of noble metals on structural, electronic, optical, and efficiency of wurtzite Cadmium sulfide (CdS) as photo-catalyst employing electronic full potential linearized augmented plane-wave (FP-LAPW) method. The structural properties are studied with PBE-sol, whereas total ground state energies for band gap, the density of states and optical absorption are calculated by using modified Becke-Johnson generalized gradient approximation (mBJ-GGA). The calculations show that the Rh and Ir as mono-doped in Cd sites are stable candidates for photo-catalytic splitting of water. For the requirements of photocatalytic splitting of water to produce hydrogen, we have calculated the edge potentials of conduction and valence band. Rh and Ir as mono-doping in Cd sites increase the difference of electron-hole ratios that lead to small recombination rate of electron-hole photo-generated pairs. For optical properties, the incorporation of Rh and Ir in CdS lattice, the optical absorption in visible spectra increases with increasing concentration and it reflects the efficient for photo-catalytic activity.