A Simple Template‐Free Strategy to Synthesize Nanoporous Manganese and Nickel Oxides with Narrow Pore Size Distribution, and Their Electrochemical Properties

Abstract

A facile method has been developed to synthesize nanoporous manganese and nickel oxides with polyhedron particle morphologies, high surface areas and narrow pore distributions by controlled thermal decomposition of the oxalate precursors. This method can be extended to using other kinds of salt precursors to prepare a series of nanoporous metal oxides. The heating rate, calcination temperature and controlled particle size of the oxalate precursors are important factors to get well‐defined pore structures. XRD, TG‐DTA, TEM, SEM, XPS, wet chemical titration and N2 sorption isotherm techniques are employed for morphology and structure characterizations. High surface area microporous manganese oxide (283 m2 g−1) and mesoporous nickel oxide (179 m2 g−1) with narrow pore distribution at around 1.0 nm and 6.0 nm, respectively, are obtained. Especially, we can tune the pore size of manganese oxides from microscope to mesoscope by controlling the thermal procedure. Electrochemical properties of manganese and nickel oxides are studied by cyclic voltammetry measurements in a mild aqueous electrolyte, which shows a high specific capacitance of 309 F g−1 of microporous manganese oxide and a moderately high specific capacitance of 165 F g−1 of mesoporous NiO due to their nanoporous structure, presenting the promising candidates for super capacitors (SC).

Significantly Improved Catalytic Performance of Ni-Based MgO Catalyst in Steam Reforming of Phenol by Inducing Mesostructure

“…In addition, the BET surface area of NiO/meso-MgO is about 2.1 times that of NiO/MgO. As seen in Figure 4, mesoporous MgO and NiO/meso-MgO exhibit the type IV isotherms according to the IUPAC classification with hysteresis loops between H3 (Figure 4b) and H1 (Figure 4d) [19,20]. The results confirm the presence of mesoporous structure in these samples, in agreement with XRD results [21].…”

Achieving High‐Performance Supercapacitors by Constructing Porous Zinc–Manganese Oxide Microstructures

“…2015,3,820 -824 2 015Wiley-VCH Verlag GmbH &Co. KGaA,W einheim structure is considered outstanding compared with many reported nanostructured Mn-based materials for supercapacitors,s uch as:n anoporous MnO 2 (309 Fg À1 ), [23] mesoporous MnO 2 with 3D frameworks( 200 Fg À1 ), [24] hierarchical MnO 2 porous nanostructures (328 Fg À1 ), [25] and MnO 2 nanosheets/ graphene (263 Fg À1 ). [26] We attribute the excellent properties to the desirable synergy of compositiona nd nanostructure.…”

“…[2,3] Tr ansition metal oxides are one important group of pseudocapacitive electrode materials and can provide higher energy density in comparison to the electrical double layer capacitive materials such as carbon-based active materials.R ecently,b inary metal oxides have been reportedt od emonstrate better performance than single-component oxides due to their feasible oxidations tates and high electrical conductivity. [4][5][6][7][8] Tr ansition metal-oxalate-based micro/nanomaterials have recently been explored as precursors for the synthesiso fp oroust ransition metal oxides (Mn 2 O 3 , [9] NiO, [9,10] CeO 2 , [11] etc.) and porous mixed transition metal oxides (NiMn 2 O 4 , [12] Ni 0.3 Co 2.7 O 4 , [13,14] ZnO-NiO, [15] etc.).…”

Pyrolysis of a Three‐Dimensional MnII/MnIII Network To Give a Multifunctional Porous Manganese Oxide Material

“…[33] The surface area obtained is also higher than that of some reported ). [34,35] Mn 2 O 3 is known to show pseudo-capacitance which arises due to highly reversible surface redox reactions. [27,36,37] Observing the porous nature of the a-Mn 2 O 3 produced by pyrolysis of 1, it was expected that the compound may show high capacitance due to the large accessible surface area for electrochemical redox reactions.…”