Copper nanoparticles (CuNPs) for metal-metal bonding were prepared by aqueous reduction with D-glucose and polyvinylpirrolidone (PVP). Increasing the cupric concentration in the range 0.1–1.0 M resulted in a progressive increase in CuNPs size from 30 nm to 200 nm. Fourier-transform infrared spectroscopy (FTIR) revealed as the PVP groups responsible for capping were C–N and C[dbnd]O at low cupric concentration and only C[dbnd]O at higher concentration. X-ray absorption fine structure (XAFS) revealed as the reduction occurred in two steps, with a fast reduction of CuO to Cu2O and a slower reduction of Cu2O. The reaction kinetics was modeled as a series of two irreversible first order reactions based on XAFS results. LC-MS highlighted as D-glucose oxidized to gluconate, glycerate, glycolate and oxalate. Increasing the D-glucose concentration did not affect the kinetics but resulted in smaller CuNPs. The electrical resistivity of the CuNPs material sintered at 300 °C was 36 µΩ cm.
ASJC Scopus subject areas
- 化学 (全般)