MnO2/ZnO porous film: Electrochemical synthesis and enhanced supercapacitor performances

• MnO2/ZnO porous film was synthesized by an electrochemical route.
• The as-prepared MnO2/ZnO film showed a uniform porous structure.
• The MnO2/ZnO porous film showed good capacitive behavior.
• The specific capacitance of compound film was three times larger than that of the single MnO2 film.

MnO2/ZnO porous compound film was synthesized by a two-step electrochemical route at room temperature. The structure and surface morphology of the as-prepared MnO2/ZnO film were characterized by X-ray diffraction and scanning electron microscopy. The supercapacitive behavior of the as-prepared MnO2/ZnO film in aqueous 0.1 M Na2SO4 electrolyte was studied by cyclic voltammetry, charge/discharge cycling and electrochemical impedance spectroscopy. In addition, single MnO2 film was also synthesized and characterized by the same method for comparison. The SEM results show that the as-prepared MnO2/ZnO film exhibits a uniform porous net structure while the single MnO2 film shows a bulk structure with uneven surface morphology. The electrochemical results indicate that the MnO2/ZnO porous film shows good capacitive behavior with a specific capacitance of 570.9 μF cm− 2 which is three times larger than that of the single MnO2 film (179.4 μF cm− 2), which reveals a potential application prospect in electrochemical supercapacitors.