Cobalt-Doped Manganese Dioxide Hierarchical Nanostructures for Enhancing Pseudocapacitive Properties

Abstract

Herein, overall improvement in the electrochemical performance of manganese dioxide is achieved through finetuning the microstructure of partially Co-doped manganese dioxide nanomaterial using facile hydrothermal method with precise control of preparative parameters. The structural investigation exhibits formation of a multiphase compound accompanied by controlled reflections of α-MnO 2 as well as γ-MnO 2 crystalline phases. The morphological examination manifests the presence of MnO 2 nanowires having a width of 70−80 nm and a length of several microns. The Co-doped manganese dioxide electrode displayed a particular capacitive behavior along with a rising order of capacitance concerning with increased cobalt ion concentration suitable for certain limits. The value of specific capacitance achieved by a 5% Co-doped manganese dioxide sample was 1050 F g −1 at 0.5 A g −1 , which was nearly threefold greater than that achieved by a bare manganese dioxide electrode. Furthermore, Co-doped manganese dioxide nanocomposite electrode exhibits exceptional capacitance retention (92.7%) till 10,000 cycles. It shows the good cyclability as well as stability of the material. Furthermore, we have demonstrated the solid-state supercapacitor with good energy and power density.

Rational Construction of Yolk–Shell Bimetal-Modified Quinonyl-Rich Covalent Organic Polymers with Ultralong Lithium-Storage Mechanism

“…As shown in Figure e,f, a capacitive contribution of 91.6% was calculated at 1.0 mV s –1 , indicating the pseudocapacitive-dominated process of the Co@2AQ-MnO 2 electrode. Given all these facts, it can be concluded that the coordination of Co 2+ could improve charge transfer and pseudocapacitive behavior of Co@2AQ-MnO 2 and further lead to the superior capacitive-controlled mechanism. , …”

“…Given all these facts, it can be concluded that the coordination of Co 2+ could improve charge transfer and pseudocapacitive behavior of Co@2AQ-MnO 2 and further lead to the superior capacitive-controlled mechanism. 82,83 CONCLUSION In summary, a bimetal-modified quinonyl-rich covalent organic polymer with abundant active sites (2AQ) has been successfully synthesized as the anode of LIBs. With the aim to improve the utilization of redox active sites of 2AQ in LIBs, petal-like nanosized MnO 2 and cobalt ions are introduced into the 2AQ matrix through in situ oxidation intercalation and coordination interactions.…”

Influence of nickel doping on MnO2 nanoflowers as electrocatalyst for oxygen reduction reaction

“…Precious metals such as Platinum (Pt) and Pt-based alloys are the most effective ORR electrode substances [18,19]. However, the application of Pt and its derivatives as ORR catalysts is limited because of their poor stability, limited access, and high price [20, into MnO 2 such as Iron (Fe), Nickel (Ni) [38], Chromium (Cr), Cobalt (Co) [39], Copper (Cu) [40], Molybdenum (Mo) [41], Aluminum (Al) [42], and Vanadium (V) [43]. Those results exhibited that doping improves the overall performance of MnO 2 NPs [44].…”

Room Temperature Acid-Free Greener Synthesis of Imine Using Cobalt-Doped Manganese Tungstate

“…15 In the host lattice of MT, we choose to dope the Co 2+ ion because of its similar size to Mn 2+ . The incorporation of Co 2+ in the lattice is easier because of similar dynamics around Mn and W. 16 There are several reports of the superiority of the Co 2+ ion over the other metal ions in manganese-based oxides for application in supercapacitor 17 and selective catalytic reduction reactions. 18 Moreover, Co 2+ doping in metal oxide catalysts is known to enhance the catalytic activity for C−H activation, 19 oxidation reactions, 20 and coupling reactions.…”