Production and characterization of CuCrO sub(2) nanofibers

Composite nanofibers were prepared from homogeneously mixed copper chloride, chromium nitrate and polyvinylpyrrolidone solution by electrospinning and were subsequently heat treated under isochronal and isothermal annealing conditions. In the isochronal experiments, CuCrO sub(2) formation began at 773 K. Annealing at 973 K yielded single-phase, highly porous CuCrO sub(2) nanofibers accompanied by the formation of large quasi-hexagonal grains. In contrast, isothermal annealing at 973 K resulted in the formation of phase-pure CuCrO sub(2) nanofibers with belt-like morphology and relatively higher density. A substantial decrease was observed in the size and number of plate-like grains in these nanofibers. When the fibers were annealed isothermally at 973 K for 1 h, the average width and specific surface area of the synthesized fibers were 150 nm and 7.85 m super(2) g super(-1), respectively, and the direct bandgap was 2.82 eV. The CuCrO sub(2) behaved like a semiconductor, and the thermally activated energy was approximately 0.157 eV. A simple formation mechanism was proposed for the quasi-hexagonal grains.