Surface characterisation of chemically reduced electrolytic manganese dioxide

Electrochemical Impedance Spectroscopy Study into the Effect of Titanium Dioxide Added to the Alkaline Manganese Dioxide Cathode

“…To determine these values it is necessary to know both the degree of reduction (readily determined from the amount of charge passed) and the unit cell volume at each voltage step. The changes which occur in the unit cell volume during reduction of c-MnO 2 have been previously reported byMalloy and Donne,41 and by making use of these values [H þ ] was determined for certain x in MnO x values (as shown in…”

Mesoporous Manganese Dioxide Coated Gold Nanorods as a Multiresponsive Nanoplatform for Drug Delivery

“…−17.1 mV. It may be that because the synthetic condition of the MnO 2 is alkaline, the −OH was attracted to the surface instead of clean surfaces and a large number of hydroxyl groups were obtained on the surface of Au/MnO 2 nanoparticles. , The ζ potential of Au/MnO 2 nanoparticles was ca. +13.6 mV after DOX was loaded (Au/MnO 2 -DOX).…”

Sulfur Dioxide Capture by Heterogeneous Oxidation on Hydroxylated Manganese Dioxide

“…Although metal oxide surfaces commonly get hydroxylated by dissociating water molecules, the formation of interfacial hydroxyl groups and their reactivity largely depend on the electronic properties and cell geometries of metal oxide surfaces. , The electronegativity of the metal atom is originally an important factor that determines the Lewis acidity and basicity of surface atoms, and therefore their bond energies with hydroxyls and potential to dissociate water. Cell geometries, on the other hand, majorly influence the kinetics of hydroxyls. , Previous studies have shown that the surface of manganese dioxide (MnO 2 ) exhibits an amphoteric nature that is characterized by the presence of both Lewis acidic and basic hydroxyl groups. , The formation of such an amphoteric hydroxylated surface could be attributed to the proper surface properties of MnO 2 which prefers adsorption of H 2 O with degenerate energies of associative and dissociative states . Moreover, transformations between acidic and basic hydroxyls were also suggested to proceed on MnO 2 along with the changing of surface redox states. , Both of these experimental and theoretical results indicate that hydroxyl groups on MnO 2 exhibit active intermediate states between acidic and basic, corresponding to electrophilic and nucleophilic, which could contribute to its exceptional activities for various catalytic redox processes. ,− The role of hydroxyls on manganese oxides in catalytic oxidation has also been highlighted by a recent study .…”

“…Cell geometries, on the other hand, majorly influence the kinetics of hydroxyls. , Previous studies have shown that the surface of manganese dioxide (MnO 2 ) exhibits an amphoteric nature that is characterized by the presence of both Lewis acidic and basic hydroxyl groups. , The formation of such an amphoteric hydroxylated surface could be attributed to the proper surface properties of MnO 2 which prefers adsorption of H 2 O with degenerate energies of associative and dissociative states . Moreover, transformations between acidic and basic hydroxyls were also suggested to proceed on MnO 2 along with the changing of surface redox states. , Both of these experimental and theoretical results indicate that hydroxyl groups on MnO 2 exhibit active intermediate states between acidic and basic, corresponding to electrophilic and nucleophilic, which could contribute to its exceptional activities for various catalytic redox processes. ,− The role of hydroxyls on manganese oxides in catalytic oxidation has also been highlighted by a recent study . Therefore, the hydroxylated surface of MnO 2 represents a strong candidate for heterogeneous capture of SO 2 .…”

“…13,14 Previous studies have shown that the surface of manganese dioxide (MnO 2 ) exhibits an amphoteric nature that is characterized by the presence of both Lewis acidic and basic hydroxyl groups. 15,16 The formation of such an amphoteric hydroxylated surface could be attributed to the proper surface properties of MnO 2 which prefers adsorption of H 2 O with degenerate energies of associative and dissociative states. 17 Moreover, transformations between acidic and basic hydroxyls were also suggested to proceed on MnO 2 along with the changing of surface redox states.…”