Dielectric, optical and enhanced photocatalytic properties of CuCrO2 nanoparticles

Abstract

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.