Terlayer space. At 350 C, diffractograms include only two reflections belonging to the class of Cyclopamine site hydrotalcites.Figure 6. Powder XRD patterns of Mg/AlNi-25-c calcined at diverse temperatures.Figure 6. Powder XRD patterns of Mg/AlNi-25-c calcined at different temperatures.The transform inside the morphology of LDHs upon heating was studied applying transmission electron microscopy. In Figure 7, it is clearly observed that with heating the hexagonal flakes steadily cease to become NBQX Formula distinguishable. Following calcination at 200 , they may be nonetheless clearly visible in micrographs, and it is actually pretty much not possible to distinguish them immediately after cal-Crystals 2021, 11,8 ofCrystals 2021, 11,A rise in temperature above 400 degrees leads to the complete destruction of the LDH structure plus the formation of a mixture of oxides, which at a temperature of 50000 C are converted into spinel phases. Figure 6 also shows the change inside the color in the LDH depending on the heating temperature. At area temperature, the sample is black; additional heating to 250 C leads to a modify inside the colour on the sample to gray-blue, which can be probably linked using the onset of the reduction of nickel. Additional heating results in the complete transformation of Ni(III) into Ni(II). The thermal transformations for two other LDH samples were demonstrated to become essentially the identical. The adjust within the morphology of LDHs upon heating was studied working with transmission electron microscopy. In Figure 7, it can be clearly seen that with heating the hexagonal flakes steadily cease to become distinguishable. Immediately after calcination at 200 C, they may be nevertheless clearly visible 9 of in micrographs, and it really is just about impossible to distinguish them right after calcination at 400 C. 13 Oxides are formed at 400 C, and at 600 C oxides are agglomerated into spinel phases.Figure 7. TEM micrographs of Mg/AlNi 25-ht heated at unique temperatures: (1) RT, (two) 200 C, Figure 7. TEM micrographs of Mg/AlNi 25-ht heated at distinct temperatures: (1) RT, (2) 200 , (3) 400 C, (4) 600 C. (3) 400 , (4) 600 .The specific surface location of the Mg/AlNi 25-c sample calcined at 600 C is 150 m2 /g. two The existing investigation, the determination from the oxidation state of nickel in the LDH In thespecific surface area of the Mg/AlNi 25-c sample calcined at 600 is 150 m /g. Within the by far the most difficult. XPS permitted in the oxidation state of nickel in the LDH samples was current analysis, the determination us to obtain information about the nickel samples state. essentially the most difficult. XPS permitted uscloseobtain information causes the oxidation was Binding energies for Ni(III) and Ni(II) have to values, and this fact about nickel oxidation state. Binding energies for Ni(III) publication of Haoyan Liang and troubles within the identification of nickel species. In theand Ni(II) have close values, et al.,this truth causes troubles in the identification of nickel species. Inside the publication of Haoyan Liang et al., it was shown that the peak at 854.7 eV corresponds to Ni(III), and also the peak at 856.1 eV corresponds to Ni(II) [31]. These values have been taken as references. The binding energy for nickel from NiO obtained by calcining LDHs acted to get a comparison. Figure 8a shows overview X-ray photoelectron spectra of the samples of Mg/AlNi-Crystals 2021, 11,9 ofCrystals 2021, 11,it was shown that the peak at 854.7 eV corresponds to Ni(III), and also the peak at 856.1 eV corresponds to Ni(II) [31]. These values were taken as references. The binding power for nickel from.