Room Temperature Synthesis of Cu₂O Nanospheres: Optical Properties and Thermal Behavior

Abstract

The present work reports a simple and easy wet chemistry synthesis of cuprous oxide (Cu2O) nanospheres at room temperature without surfactants and using different precursors. Structural characterization was carried out by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy coupled with focused ion beam and energy-dispersive X-ray spectroscopy. The optical band gaps were determined from diffuse reflectance spectroscopy. The photoluminescence behavior of the as-synthesized nanospheres showed significant differences depending on the precursors used. The Cu2O nanospheres were constituted by aggregates of nanocrystals, in which an on/off emission behavior of each individual nanocrystal was identified during transmission electron microscopy observations. The thermal behavior of the Cu2O nanospheres was investigated with in situ X-ray diffraction and differential scanning calorimetry experiments. Remarkable structural differences were observed for the nanospheres annealed in air, which turned into hollow spherical structures surrounded by outsized nanocrystals.

Mapping the Cu-BTC metal–organic framework (HKUST-1) stability envelope in the presence of water vapour for CO2 adsorption from flue gases

“…4). Two exothermic peaks were discovered by DCS analysis after 280°C with first exothermic peak (280-300°C) corresponds to the formation of Cu 2 O [43] and the second one corresponds to the phase transformation of Cu 2 O to CuO [44].…”

Microwave Synthesized ZnO Nanorod Arrays for UV Sensors: A Seed Layer Annealing Temperature Study

“…This celerity is possible due to the fact that microwaves transfer energy directly to the reactive species [28]. Moreover, this synthesis route has been used for other materials, forming homogeneous and uniform nanostructured films [29,30]. …”

Metal oxide nanostructures for sensor applications

“…and CuO materials, such as nanowires [384][385][386], nanorods [387,388], nanobelts [389,390], nanowhiskers [391,392], nanocubes [55,393,394], octahedral nanostructures [395,396], nanospheres [349,[397][398][399][400], hierarchical nanostructures [401], and others ( Figure 18). CuO nanowires [386].…”

“…SEM images of Cu2O spheres in (a)[55] and (b)[349], (c) CuO nanotubes, (d) Cu2O nanowires[11], (e) Cu2O nanocubes, (f) CuO nanospheres[349], (g) hierarchical hollow Cu2O microspheres[401] (h)…”