Dielectric, optical and enhanced photocatalytic properties of CuCrO2 nanoparticles
Herein, delafossite CuCrO2 nanoparticles were synthesized through a polymeric citrate precursor method, followed by heating at 900 °C in air. The BET surface area of the CuCrO2 nanoparticles was found to be 235 m2 g−1, which was more than 500 times that of bulk CuCrO2 (0.47 m2 g−1) and 2–4 times that of the reported CuCrO2 nanoparticles (50–100 m2 g−1) (Y.-T. Nien et al., Mater. Chem. Phys., 2016, 179, 182–188 and D. Xiong et al., J. Mater. Chem., 2012, 22, 24760–24768). In the photoluminescence spectra of the CuCrO2 nanoparticles, a strong luminescent emission peak was observed at ∼460 nm in the blue light region. The resulting transmittance value of the CuCrO2 nanoparticles was found to be 77% in the visible region, and the direct band gap energy was determined to be 3.09 eV via UV-vis spectroscopy. The dielectric properties as a function of frequency and temperature and photocatalytic degradation of the organic pollutants in an aqueous solution were also investigated. CuCrO2 nanoparticles also showed remarkable enhancement in the catalytic degradation of methylene blue in H2O under sunlight irradiation. The plausible fragmentation and the structural changes in the methylene blue molecule were further demonstrated via mass spectrometry.