Evidence and analysis of parallel growth mechanisms in Cu2O films prepared by Cu anodization

Comparative AFM nanoscratching tests in air of bulk copper and electrogenerated cuprous oxide films

“…As this latter can be easily evaluated with a satisfying accuracy from Figure 8, the value extracted for the hardness of Cu 2 O possibly suggests that the nanoscratching test may not have sollicitated the hardness of the cuprous oxide film but rather another fundamental characteristic of this material such as the adhesion between the constituting grains of the material. Indeed, in the particular case of cuprous oxide, the material structure resulting from the electrodeposition process is presumably heterogeneous due to a grainy structure [36]. In other words, one can suggest that nanoscratching tests actually allow appealing to the adhesion forces existing between the grains, whether they are made of nanometric Cu 2 O or CuCl (see Figure 4 and 5).…”

“…Again, the feasibility was easily shown but the narrow correlations between topography on one side and deflection and friction on the other side are much weaker even though the roughness and z-scale take values close to those measured on the bulk copper samples. By comparison with the granular aspect of the electrodeposited cuprous oxide film[36], the scratched zone resulting from the softest nanoscratching test (one scan, applied normal load: 0.623 μN, seeFig. 6) appears to be smoothened, indicating a wear threshold situation.…”

Morphology and photoluminescence of nanostructured oxides grown by copper passivation in aqueous potassium hydroxide solution

“…Nanostructures made of cuprous and cupric oxides are gaining increased research interest due to their electrical and optical properties and potential applications in renewable energy harvesting [1][2], sensing and morphologically tuned surface wetting [1,3]. One of the recently reported and facile approaches of copper and cupric oxide fabrication is self-organized anodization of copper substrates which allows to form nanowires made of copper compounds like Cu 2 O, CuO and Cu(OH) 2 [2][3][4][5][6]. According to the Pourbaix diagram for copper, passivation is typically conducted in base solutions of NaOH [2][3]5] and KOH [4,6].…”

“…One of the recently reported and facile approaches of copper and cupric oxide fabrication is self-organized anodization of copper substrates which allows to form nanowires made of copper compounds like Cu 2 O, CuO and Cu(OH) 2 [2][3][4][5][6]. According to the Pourbaix diagram for copper, passivation is typically conducted in base solutions of NaOH [2][3]5] and KOH [4,6]. Despite some preliminary research on nanostructuring of copper surfaces, there are still many fundamental aspects to be explored like: investigation of the chemical composition, microstructure and morphology of the grown nanostructures.…”

Synthesis of copper and zinc oxides nanostructures by brass anodization in alkaline media

“…Although there is no previous study on the preparation and characterization of these two oxides simultaneously, by anodization, there are several researches that have studied the synthesis of copper oxide [3,18,19] and zinc oxide [2,9] separately, by anodization. However, presence of these elements in the oxide lattice, Zn in copper oxide or Cu in zinc oxide lattice can improve its optical and electrical properties like band gap condition [14][15][16].…”