We have created hybrid organic−inorganic nanoarchitectures by electrodepositing ultrathin (<10-nm-thick) polymer coatings onto nanostructured MnO2 birnessite-type electrodes with surface areas in excess of 200 m2 g-1. By choosing a self-limited growth process, based on the electropolymerization of o-phenylenediamine, the resulting polymer conformally coats the oxide nanoscale network without di...

Battery grade γ-MnO2 powder was investigated as an oxidant and an adsorbent in combination with Fe/Al coagulants for removal of arsenic from contaminated water. Simultaneous oxidation of As(III) and removal by coprecipitation/adsorption (one step process) was compared with pre-oxidation and subsequent removal by coprecipitation/adsorption (two step process). The rate of As(III) oxidation with M...

Here we demonstrate significant improvements in the performance of supercapacitor electrodes based on 2D MnO2 nanoplatelets by the addition of carbon nanotubes. Electrodes based on MnO2 nanoplatelets do not display high areal capacitance because the electrical properties of such films are poor, limiting the transport of charge between redox sites and the external circuit. In addition, the mecha...

Pseudo-capacitive MnO2 supercapacitors are attracting intense interest because of the theoretically high specific capacitance (1370 F g(-1)) and low cost of MnO2. For the practical application, the power density and the cyclic stability of MnO2-based supercapacitors are expected to be improved. Increasing the efficiency of the current collection is an effective method to improve the power densi...

The effect of MnO2 addition on the microstructural evolution and piezoelectric properties of low temperature sinterable PZT–PZN ceramics was investigated. When a small amount of MnO2 (≤0.5 wt% ) was added, the Mn ions were homogeneously dissolved in the PZT– PZN ceramics, leading to full densification at a temperature as low as 930 °C. However, the further addition of MnO2 hindered the densific...

In present investigation, we have prepared a nanocomposites of highly porous MnO2 spongy balls and multi-walled carbon nanotubes (MWCNTs) in thin film form and tested in novel redox-active electrolyte (K3[Fe(CN)6] doped aqueous Na2SO4) for supercapacitor application. Briefly, MWCNTs were deposited on stainless steel substrate by "dip and dry" method followed by electrodeposition of MnO2 spongy ...

the supercapacitive behavior of polyaniline/mno2-carbon black (pani/mno2-cb), mno2-cb nanocompositesand cb was studied. mno2-cb made by the in situ direct coating method to deposit mno2 onto cb; then pani coating was coated on it. morphology of the nanocomposite was studied by x-ray diffraction (xrd), fourier transform infrared (ft-ir) spectroscopy and scanning electron microscopy (sem). the el...

Despite the extensive research on MnO2 as a pseudocapacitor electrode material, there has been no report on heterostructures of multiple phase MnO2. Here we report the combination of two high-capacitance phases of MnO2, namely, a-MnO2 nanowires and d-MnO2 ultrathin nanoflakes, to form a core-branch heterostructure nanoarray. This material and structure design not only increases the mass loading...

Different polymorphs of MnO2 (α-, β-, and γ-) were produced by microwave hydrothermal synthesis, and graphene oxide (GO) nanosheets were prepared by oxidation of graphite using a modified Hummers' method. Freestanding graphene/MnO2 cathodes were manufactured through a vacuum filtration process. The structure of the graphene/MnO2 nanocomposites was characterized using X-ray diffraction (XRD) and...

BACKGROUND Organic dye pollution in water has become a major source of environmental pollution. Mn(III/IV) oxides have attracted a great deal of attention to remove organic dye pollutants due to their unique structures and physicochemical properties. Numerous studies have reported the removal of dye by various Mn(III/IV) oxides through catalytic degradation and adsorption. The crystalline struc...