20.500.12556/DKUM-67303 Structural properties and thermal stability of cobalt- and chromium-doped $α-MnO_2$ nanorods $α-MnO_2$ nanorods were synthesized via the hydrothermal decomposition of $KMnO_4$ in an acidic environment in the presence of $Co^{2+}$ and $Cr^{3+}$ ions. Reactions were carried out at three different temperatures: 90, 130 and 170 °C. All prepared samples exhibit a tetragonal $MnO_2$ crystalline phase. SEM–EDS analysis shows that cobalt cations are incorporated to a higher degree into the $MnO_2$ framework than chromium ions, and that the content of the dopant ions decreases with increasing reaction temperature. The oxidation of $Co^{2+}$ to $Co^{3+}$ during the reaction was proved by an XANES study, while EXAFS results confirm that both dopant ions substitute $Mn^{4+}$ in the center of an octahedron. The K/Mn ratio in the doped samples synthesized at 170 °C is significantly lower than in the undoped samples. Analysis of an individual cobalt-doped $α-MnO_2$ nanorod with HAADF-STEM reveals that the distribution of cobalt through the cross-section of the nanorod is uniform. The course of thermal decomposition of the doped nanorods is similar to that of the undoped ones. Dopant ions do not preserve the $MnO_2$ phase at higher temperatures nor do they destabilize the cryptomelane structure. $α-MnO_2$ manganese dioxide doping EXAFS nanorods XANES $α-MnO_2$ manganov dioksid dopiranje EXAFS nanopalčke XANES true false true Angleški jezik Slovenski jezik Znanstveno delo 2017-08-10 08:40:28 2017-08-10 08:42:03 2022-08-01 13:47:53 2019-07-11 16:15:49 2017 0 0 str. 1032-1042 Letn. 8 2017 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 2190-4286 546.711-31:620.3 25644839 1537419971 10.3762/bjnano.8.104 2190-4286 URN:SI:UM:DK:1M6PJSNJ Beilstein_Journal_of_Nanotechnology_2017_Cerc_Korosec_et_al._Structural_properties_and_thermal_stability_of_cobalt-_and_chromium-doped_α.pdf Beilstein_Journal_of_Nanotechnology_2017_Cerc_Korosec_et_al._Structural_properties_and_thermal_stability_of_cobalt-_and_chromium-doped_α.pdf 1 1711B3579EB146884854FF82B1F131AB 07e1526f157c7cdd35b7cbc8ee21ae5d309226f876272818c09f80ff2fe812ae 800f5849-7c0e-11eb-bb7a-00155d0001ca 20.500.12556/dkum/a7c928ee-7bc4-4ff9-ab54-15f374bd7fd2 https://dk.um.si/Dokument.php?lang=slv&id=115126 http://www.beilstein-journals.org/bjnano/content/8/1/104 1 https://dk.um.si/Dokument.php?lang=slv&id=115125 Fakulteta za strojništvo 0 0 0