Synthesis and charge storage properties of templated LaMnO3–SiO2 composite materials

Abstract

Mesoporous LaMnO₃ with bulk surface areas in the range 225–300 m² g⁻¹ were prepared by direct overgrowth around the short-channel version of SBA-15 silica. The extent of LaMnO₃ growth was found to be affected by the polarity of solvent system used to impregnate the SBA-15 with La³⁺ and Mn²⁺ precursors. The resulting LaMnO₃–SiO₂ composites were stable in refluxing NaOH, suggesting that the SiO₂ was fully encapsulated. The composites were structurally characterized using a range of techniques including 2-D elemental mapping and Raman spectroscopy. The electrochemical behavior of the composites was tested for pseudocapacitance, which revealed normalized specific capacitances over 200 F g⁻¹.