Synthesis of γ-MnOOH nanorods by successive ionic layer deposition method and their capacitive performance

Abstract

It was first shown in the present study that layers of manganite γ-MnOOH can be deposited on the surface of a substrate by its multiple successive treatment by the solutions of MnSO4 and K2S2O8 using the successive ionic layer deposition (SILD) technique. Their analysis was carried out by the XRD, XPS, FT-IR, SEM and EDX methods. It has shown that the synthesized layers are formed by aggregates of nanorods up to 80–100nm in length and approximately 8–10nm in diameter. A probable sequence of chemical reactions leading to the formation of a layer of the given morphology is suggested. Testing of performance of supercapacitors with nickel foam electrodes incorporating the γ-MnOOH layers in the 0.1M KOH electrolyte at 1 A/g indicated the specific capacitance equal to 1120 F/g. After 1000 work cycles the observed degradation of this value was less than 3%.