One-pot synthesis of Mn3O4-decorated GaN nanowires for drastic changes in magnetic and gas-sensing properties

Molecular Engineering of MnII Diamine Diketonate Precursors for the Vapor Deposition of Manganese Oxide Nanostructures

“…[26] In comparison to other ML 2 ·TMEDAa dducts (M = Fe, [15a] Co, [13b] Cu, [13a] Zn [29] ), the O-M-O, O-M-N, and N-M-N bond angles (Table 1) are slightly lower (up to % 58), whereas MÀOa nd MÀNd istances are longer.S imilarly to the Fe homologue, [15a] the OÀCb ond lengths of b-diketonate ligands werea ll close to 1.25 ,avalue that suggests ad ouble-bondc haracter (typical OÀCs ingle bonds % 1.40 ). For both compounds, the atomicd istances between O(1)ÀC (7) and O(4)ÀC(14) are slightly longert han those of O(2)ÀC(9) and O(3)ÀC(12), due to ÀCF 3 electron-withdrawing groups being directly bonded to C(7) and C(14) atoms. In addition, MnÀO (2) and MnÀO(3) distances were slightly longer than those trans to the Oa toms of Ll igands [MnÀO(1) and MnÀO (4), Ta ble 1 [9e] ].…”

Hydrogen Gas Sensing Performances of p-Type Mn3O4 Nanosystems: The Role of Built-in Mn3O4/Ag and Mn3O4/SnO2 Junctions

“…For the functionalized systems, a lower Mn2p3/2 BE was observed (641.7 eV, for Mn3O4-Ag, and 641.5 eV, for Mn3O4-SnO2). This finding suggested the formation of Schottky and p-n junctions for Mn3O4-Ag and Mn3O4-SnO2, respectively [33,37,38,41,42], resulting in an Ag → Mn3O4 and SnO2 → Mn3O4 electron transfer. This phenomenon, more pronounced for SnO2-containing samples, as testified by the higher BE decrease, exerted a favorable influence on the resulting gas sensing performances.…”

“…drift upon repeated tests up to 4 months, highlighting thus the system stability, an important issue in view of eventual real-world end uses [37,38,48]. The experimental response vs. concentration trends were fitted by the typical power law relation for metal oxide sensors [9,30,42]:…”

“…Over the last decade, different studies have reported on Mn 3 O 4 -containing gas sensors for various analytes, including CH 3 CH 2 OH, CH 3 COCH 3 , NH 3 and chemical warfare agent simulants [31,[35][36][37][38][39][40][41]. Nonetheless, only two works on Mn 3 O 4 -based gas sensors for molecular hydrogen detection are available in the literature so far [35,42], and the implementation of H 2 sensors endowed with improved sensitivity and selectivity undoubtedly requires additional research efforts [29,35,37,38].…”

“…Beside tailoring the system morphology [25,26,33,39], a proficient way to enhance the functionality of bare Mn 3 O 4 gas sensors involves their sensitization with suitable metal/oxide agents [8,18,35,[42][43][44]. The ultimate aim of this strategy is the exploitation of synergistical chemical and electronic effects, in order to obtain improved performances at moderate working temperatures, an issue of key importance for the development of low power consumption devices [4,37,41].…”