Decoration of one-dimensional MnO 2 with Co 3 O 4 nanoparticles: A heterogeneous interface for remarkably promoting catalytic oxidation activity

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 Co 3 O 4 -decorated one dimensional (1D) MnO 2 hybrids and their application in catalytic degradation of carcinogenic benzene. Three kinds of 1D MnO 2 including α-MnO 2 nanowires, α-MnO 2 nanorods and β-MnO 2 microrods were firstly synthesized by different hydrothermal method, followed by a controlled Co 3 O 4 functionalized process. The homogeneous coating of the Co 3 O 4 nanoparticles on the surface of the MnO 2 created large amounts of remarkable MnO 2 -Co 3 O 4 heterogeneous interface which was characterized by SEM and TEM techniques. XPS and H 2 -TPR studies revealed the decorated hybrids had better low-temperature reducibility and more active surface adsorbed oxygen species. Compared with the bare MnO 2 , these hybrid MnO 2 @Co 3 O 4 nanaostructures showed improved catalytic reactivity toward gaseous benzene oxidation, and the enhancement had different dependence upon the various MnO 2 . Under high space velocity of 120,000 mL g −1 h −1 , the best-performed α-MnO 2 nanowires@Co 3 O 4 can decrease the T 90 (temperature of 90% benzene conversion) to 247 °C which was almost 100 °C lower than the pure α-MnO 2 nanowires. Their significantly promoted catalytic activity should be attributed to the strong synergistic effect due to the existence of remarkable MnO 2 -Co 3 O 4 hetero-interface.