## 3 Results and Discussion
### Characterization of the Prepared Nanopowder
The spectral analysis findings agree well with the XRD data, which is confirmed by the presence of absorption bands associated with the above-mentioned components. Thus, the absorption band around 1530 cm\({}^{-1}\) partially overlapping with the signal from the Vaseline oil belongs to the v(OCO\({}_{2}\)) stretching vibration. The low-intensity bands at 1070 and 829 cm\({}^{-1}\) are related to v(C=O) and \(\delta\)(CO\({}_{3}\)), respectively, and the bands with maxima at 968 and 528 cm\({}^{-1}\) are attributed to \(\delta\)(M-OH) and \(\rho_{\rm w}\)(Co-OH), respectively. The indicated absorption band set is characteristic of carbonate hydroxide hydrate [56]. The broad absorption band in the 3100-3700 cm\({}^{-1}\) region probably refers to the v(O-H) stretching vibration of NiCo-LDH, and the weak signal around 1640 cm\({}^{-1}\) refers to the bending vibration, which is typical for layered metal hydroxides [59; 60]. The spectrum of the composite powder under study also exhibits an absorption band in the region of 2150-2260 cm\({}^{-1}\), probably related to v(NCO) vibrations [61]. The presence of this functional group may be connected with the formation of isocyanic acid during urea decomposition during hydrothermal treatment of the reaction system [62] in accordance with the following reaction:  
\[\rm NH_{2}-CO-NH_{2}\to NH_{3}+HNCO \tag{6}\]  
Figure 3: FTIR spectrum of the obtained powder (the “*” marker indicates Vaseline oil absorption bands). Figure 2: XRD patterns of the obtained powder (left—overview and right—for 2\(\theta\) range 30\({}^{\circ}\)–41\({}^{\circ}\) with longer signal accumulation; reflex from the nickel–cobalt layered double hydroxides phase is marked by the “*” marker). Furthermore, the incorporation of the -NCO group into the material structure is common to layered hydroxides due to the peculiarities of their structure, as follows from the FTIR results of other authors [32] who used urea as a precipitant in the synthesis of NiCo-LDH. Thus, the presence of the corresponding absorption band in the spectrum of the powder we obtained provides additional evidence for the presence of nickel-cobalt layered double hydroxides as a material component. The microstructure of the obtained powder was examined by SEM (Figure 4). The corresponding images demonstrate the presence of two structures in the material. The first is a spherical hierarchically organized structure with a diameter of 8-10 \(\upmu\)m, whose surface consists of orthogonally arranged nanorods about 1 \(\upmu\)m long and 10-50 nm thick, which agrees well with the results of the average CSR size estimation. Individual nanorods of similar size or agglomerates in the form of bundles consisting of several nanorods should be noted as the second component. The presence of two microstructural types agrees well with the XRD and FTIR powder results, which indicate the simultaneous presence of nickel-balt carbonate hydroxide hydrate M(CO\({}_{3}\))\({}_{0.5}\)(OH)-0.11H\({}_{2}\)O (where M is Ni\({}^{2+}\) and Co\({}^{2+}\)) and nickel-cobalt layered double hydroxides in the material composition. Given the literature data, the hierarchically organized spherical formations probably belong to nickel-cobalt carbonate hydroxide hydrate [63], while individual nanofibers and their bundles can be attributed to NiCo-LDH. Thus, the results of scanning electron microscopy further confirm the composite nature of the obtained nanopowder. Characterization of the Printed (M(CO\({}_{3}\))\({}_{0.5}\)(OH)-0.11H\({}_{2}\)O)/(NiCo-LDH) Film  
Functional inks obtained from the hierarchically organized (M(CO\({}_{3}\))\({}_{0.5}\)(OH)-0.11H\({}_{2}\)O)/ (NiCo-LDH) (where M is Ni\({}^{2+}\) and Co\({}^{2+}\)) nanopowder were further used for the microplotter printing of an electrode film on the surface of a nickel-plated steel substrate on both sides (Figure 5a).