A Comparative Study of Structural and Optical Properties of Cu2O Nanocrystals for Solar Water Splitting Applications

The Cu₂O nanocrystals were successfully synthesized by colloidal chemistry method for two different growth temperatures are 50°C and 75°C for 5 hrs. The synthesized nanocrystals were characterized by the X-ray diffraction (XRD) and UV-visible spectrometer. The XRD pattern confirmed the presence of phases of Cu₂O nanocrystals. The average crystallite size of the nanocrystal was found to be around 17.11 nm and 19.55 nm respectively. The absorption spectra of the samples exhibited broad peaks situated at 481 nm and 516 nm respectively. From UV studies revealed that the Cu₂O nanocrystals band gap was tuned between 1.97 eV to 1.99 eV and it was compared with density functional theory based on Wien2K (FP-linear augmented plane wave) simulation employing a combined Perdew, Burke and Ernzerhof (PBE) potential. From these calculations densities of state were calculated and it was found that the band gap of Cu₂O is 2.1 eV.