Enhanced electrochemical properties of Al-doped bulk manganese oxides synthesized by a facile liquid-phase method

Aluminum doped MnO2 nanoparticles were synthesized by a simple liquid-phase process using potassium permanganate as oxidation agent, glycol as reducing agent. Specific capacitance of the optimal sample electrode can reach 290 F g−1 after 10 cycles. The electrode also exhibits excellent cycle stability, retaining 86.6 % after 1,000 cycles. The infrared absorption bands of aluminum doped manganese oxide shift to high wave number for the reason that aluminum ion has smaller nuclear charge. The doping of aluminum strengthens the Mn–O bond and decreases the aggregation degree, thus the electrochemical properties are enhanced.