Abstract

In this work, BiOCl films were obtained by tape casting using BiOCl powders synthesized by the co-precipitation method. The effect of the film's sintering temperature (300 °C–600 °C) on the morphology, chemical composition, crystalline phases and optical characteristics was studied. The obtained BiOCl powders showed a flake-like morphology, a tetragonal crystalline structure without secondary phases and a wide band gap of 3.53 eV. For BiOCl films, results indicated that as the sintering temperature increased the flake-like shaped particles changed to rectangular ones while the amount of chlorine in the films decreased. A phase transition from tetragonal BiOCl to monoclinic Bi24O31Cl10 was also observed as the sintering temperature increased. Consequently, optical studies revealed that the band gap of BiOCl films decreased from 3.03 eV to 2.82 eV. FTIR analysis demonstrated that the organic groups were removed from the films only for sintering temperatures above 400 °C. The Rhodamine B dye adsorption capacity of BiOCl films decreased with increasing sintering temperature. The results obtained allow us to conclude that BiOCl films are suitable for use in DSSC when the sintering temperature is in the range of 400–500 °C. © 2023 Elsevier Ltd and Techna Group S.r.l.