Manganese dioxide nanoparticles and nanocomposites with carbon black. Synthesis, physical-chemical and electrical properties

Abstract

In this study, α- and β-MnO2 and composites with carbon black (CB) were chemically synthesized and prepared through mechanical mixing respectively. The samples’ crystal structure, morphology, and electrical properties have been investigated herein. It is found that average particle sizes of 12–15 nm and 18–24 nm for α- and β-MnO2, respectively. The surface area and average pore volume of obtained samples of α- and β-MnO2 are 200 and 70 m2/g, and 3.2 and 5.3 nm, respectively. The electrical conductivity performances and activation energy behavior of samples have been analyzed. The correlation between the CB content in the composites and their electrical conductivity was established based on experimental data. The electrical conductivity of the α-MnO2/C monotonic increase from 1.31 to 18.6 S/m. There was a 7.5-fold increase of conductivity for α-MnO2 with 15 wt.% CB and almost a 30-fold increase for β-MnO2 with the corresponding CB content compared to the pure samples. In composite samples, the activation energy decreases from 0.069 to 0.041 eV and from 0.154 to 0.074 eV for α- and β- MnO2/C, respectively.