关键词: 硼掺杂, 四氧化三钴, 气敏特性, 气敏机制

Abstract: Cobalt oxide (Co3O4) is a p-type semiconductor that can be used as a gas-sensing material. Non-metallic boron (B) has the characteristic of absorbing electrons. Doped it with p-type semiconductor gas-sensing material can increase the concentration of hole carrier of the material, thus improving the gas-sensing property of the material. In this paper, B-doped Co3O4 sea urchins microspheres were successfully prepared by low-temperature one-step hydrothermal method with cobalt nitrate hexahydrate (Co(NO3)2·6H2O), boric acid (H3BO3) and urea (Co(NH2)2) as raw materials. The structure of Co3O4 before and after boron doped was characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectrometer (XPS) and Raman spectrometer (Raman), to explore the influence of boron doped on its gas-sensing performance. The results showed that boron doped significantly enhanced the gas sensing properties of Co3O4. When the doped molar ratio was Co: B= 8:1, the optimal working temperature of B-Co3O4 for 1×105μg/L ethanol was 180℃, and the sensitivity response reached 26.8, which was 4.4 times that of pure Co3O4 under the same conditions. B-Co3O4 is an excellent gas sensing material with good sensitivity, selectivity and stability under low operating temperature.

Key words: boron doped, cobalt oxide, gas-sensing properties, gas sensing mechnism