Effect of sulphuric acid (H2SO4) on the growth process of two-dimensional zinc oxide (ZnO) structures prepared by chemical bath deposition

In this work, the effect of sulphuric acid (H2SO4) on the transformation of ZnO from its one-dimensional to two-dimensional structure was addressed. Here, the addition of H2SO4 of varying concentrations (5 mM, 10 mM, and 15 mM) into the precursor solution was done using the process of chemical bath deposition. Several characterisation methods such as X-ray diffraction (XRD), field-effect electron scanning microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL) were then utilised to investigate the impact of H2SO4 on the prepared samples. The results subsequently revealed the morphological transformation of the ZnO samples from one-dimensional (1D) to two-dimensional (2D) morphology structures at the H2SO4 concentrations of 10 mM and 15 mM. Besides, the PL spectra for the samples prepared using varying H2SO4 concentrations displayed a red shift in the UV emission peak as the percentage was increased, as well as a decrement in its intensity. Based on the findings of this study, it can be concluded that the morphology of 1D ZnO nanorods can be converted to 2D via adjustments made to the H2SO4 content.