An effective approach to prepare three-dimensional porous manganese dioxide electrodes by surfactant assisted electrosynthesis for improved supercapacitive properties

    We report here a simple and effective strategy to promote supercapacitive properties of the MnO₂ electrode, in which sodium dodecyl benzene sulfonate (DBS) as an anionic surfactant is added into the solution used for electrosynthesis. Morphology characterizations indicate that the DBS acts like a pore-forming agent, allowing the deposited MnO₂ nanofibers to form a three-dimensional porous nano-network. The formation mechanism of porous nano-network under DBS assisted electrosynthesis is analyzed accordingly. Electrochemical measurements show that the supercapacitive performance of MnO2 electrode is effectively enhanced. The MnO₂ electrode prepared with DBS presents a high specific capacitance of 259.7  F  g⁻¹at 1  A  g⁻¹, which is increased by 30.9% with respect to 198.3 F g⁻¹ for the electrode prepared without DBS. Notably, the cycle stability of MnO2 electrode is significantly improved due to the addition of DBS, which retains 91.0% of its initial capacitance for 2500 cycles. In contrast, the MnO₂ electrode prepared without DBS only maintains 48.7%. The improved properties should promote the applications of MnO₂ in electrochemical capaci