This paper investigates the comproportionation reaction of MnII with [Formula: see text] as a route for manganese oxide nanoparticle synthesis in the protein ferritin. We report that [Formula: see text] serves as the electron acceptor and reacts with MnII in the presence of apoferritin to form manganese oxide cores inside the protein shell. Manganese loading into ferritin was studied under acid...

Background: The use of nanotechnology has led to rapid growth in various areas. Thus, health and safety issues of nanoparticles (NPs) should be promptly addressed. Manganese oxide (MnO2) nanoparticles (NPs) are typically used for biomedical and industrial applications. However, characterizing the potential human health effects of MnO2 NPs is required before fully exploiting these materials. The...

New ternary composites of MnO2 nanorods, polyaniline (PANI) and graphene oxide (GO) have been prepared by a two-step process. The 100 nm-long MnO2 nanorods with a diameter ~20 nm are conformably coated with PANI layers and fastened between GO layers. The MnO2 nanorods incorporated ternary composites electrode exhibits significantly increased specific capacitance than PANI/GO binary composite in...

A new high peak power density alkaline fuel cell ~FC! was fabricated using a metal hydriding ~MH! alloy as the anode electrocatalyst and manganese dioxide as the cathode electrocatalyst. The high-loading MH and MnO2 electrocatalysts not only gave a satisfactory steady-state power output, but also deliver additional power stored in the charged MH and MnO2 electrodes when the overall cell voltage...

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 ...