Supercapacitor Electrodes Based on Hierarchical Mesoporous MnO_x/Nitrided TiO₂ Nanorod Arrays on Carbon Fiber Paper

Metal nitride nanoarrays are attractive to electrochemical energy storage and in this work, hierarchical mesoporous manganese oxide (MnO_x) nanoflakes and nitrided TiO₂ nanorod arrays (NTNA) are prepared on carbon fiber paper (CFP) by hydrothermal synthesis and electrodeposition. The MnO_x/NTNA/CFP electrode delivers outstanding electrochemical performance such as high areal capacitance of 327 mF cm^-2 at a current density of 0.25 mA cm^-2 and good cycling stability with 96% retention after 5000 cycles. Compared to the MnO_x/TiO₂/CFP and MnO_x/CFP electrodes, the MnO_x/NTNA/CFP electrode possesses better electrochemical properties such as higher areal capacitance, better electrochemical activity, and cycling life. The enhanced performance can be attributed to the nitrided TiO₂ nanorod arrays with higher conductivity offering low electrochemical impedance and fast ion/electron transfer. The MnO_x/NTNA/CFP electrode is a promising candidate in high-performance supercapacitor applications.