Facile synthesis of novel MnO2 hierarchical nanostructures and their application to nitrite sensing

Hierarchical MnO2 micro spheres composed of nanodisks were synthesized and characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM) and Brunauer–Emmett–Teller (BET) surface area analyses. MnO2/QPOE composite electrodes (denoted as MQPOE) were fabricated and characterized electrochemically to further explore their potential applications in modern industry. The MQPOE electrodes showed very high catalytic activity and much low detection limit in nitrite sensing. This unexpected result can be attributed to their large surface areas and good conductivity which resulted from the hierarchical nature of the manganese dioxide nanostructures.