Production of Cu₂O nanoparticles in SiO₂by ion implantation and two-step annealing at different oxygen pressures

Abstract

Two different methods were applied to fabricate cuprous-oxide (Cu2O) nanoparticles (NPs) in silica glasses (SiO2), namely (i) low oxygen-pressure (LOP) oxidation of Cu NPs, which had previously been formed in SiO2by implantation of Cu ions and (ii) two-step annealing of Cu NPs in atmospheric-pressure oxygen gas (to convert Cu NPs to CuO) and in LOP-Ar gas (to convert CuO to Cu2O). The LOP oxidation at 800 °C converts a small portion of Cu NPs to the Cu2O phase, but most of the Cu NPs survive in the metallic state. By increasing the oxidation temperature to 900 °C, the Cu2O phase dissolves. On the other hand, the two-step annealing at different oxygen pressures converts all the Cu species to Cu2O NPs. Any diffraction peaks due to Cu NPs or CuO NPs, except Cu2O NPs, were not observed.

Atomic‐Scale Mechanism of Unidirectional Oxide Growth

“…Our TEM characterization has confirmed the Cu 2 O and CuO formation in the in-situ TEM experiments, same as that from the ex-situ oxidation experiment at the higher pO 2 . This is also consistent with the phase diagram of the copperoxygen system that predicts the Cu 2 O and CuO formation at 400C with the oxygen pressure below ~ 0.001 Pa. [13] Previous studies have shown that the length and diameter of CuO nanowires increase with increasing pO 2 . [14] As shown below, oxide nanowires formed from the oxidation at the low pO 2 share the same microstructure feature as those from the high pO 2…”

Formation of copper aluminate spinel and cuprous aluminate delafossite to thermally stabilize simulated copper-laden sludge

“…Unlike sintering with the ␥-alumina precursor, the CuAlO 2 phase was not formed in this case at higher temperatures because of the participation of cristobalite in the system. Cuprous oxide was found to dissolve in cristobalite at higher temperatures [27]. The active energy needed for the Cu 2 O-cristobalite solution and mullite to form CuAlO 2 was too high in this temperature range.…”

Fabrication of CuO and Cu2O Nanoparticles in a Thick Polyimide Film by Post Heat Treatment in a Controlled-Atmosphere

“…[7][8][9] Many methods have been developed to produce metal-oxide nanoparticles, but aggregation between nanoparticles has been an issue. [10][11][12] To prevent the aggregation of nanoparticles, some researchers embedded the nanoparticles in the matrix, especially dielectric polymer because of its easy process. [13][14][15][16] Cuprous oxide (Cu 2 O) and cupric oxide (CuO) nanoparticles have a lot of attentions in their fundamental research and applications.…”