Decoration of one-dimensional MnO2 with Co3O4 nanoparticles: A heterogeneous interface for remarkably promoting catalytic oxidation activity

Abstract

Heterogeneous interface in materials has recently attracted much attention because of its crucial role in catalytic reaction. Herein, we report the preparation of high-quality Co3O4-decorated one dimensional (1D) MnO2 hybrids and their application in catalytic degradation of carcinogenic benzene. Three kinds of 1D MnO2 including α-MnO2 nanowires, α-MnO2 nanorods and β-MnO2 microrods were firstly synthesized by different hydrothermal method, followed by a controlled Co3O4 functionalized process. The homogeneous coating of the Co3O4 nanoparticles on the surface of the MnO2 created large amounts of remarkable MnO2-Co3O4 heterogeneous interface which was characterized by SEM and TEM techniques. XPS and H2-TPR studies revealed the decorated hybrids had better low-temperature reducibility and more active surface adsorbed oxygen species. Compared with the bare MnO2, these hybrid MnO2@Co3O4 nanaostructures showed improved catalytic reactivity toward gaseous benzene oxidation, and the enhancement had different dependence upon the various MnO2. Under high space velocity of 120,000mLg−1h−1, the best-performed α-MnO2 nanowires@Co3O4 can decrease the T90 (temperature of 90% benzene conversion) to 247°C which was almost 100°C lower than the pure α-MnO2 nanowires. Their significantly promoted catalytic activity should be attributed to the strong synergistic effect due to the existence of remarkable MnO2-Co3O4 hetero-interface.