硼掺杂Co3O4海胆状微球的制备及其乙醇气敏强化机制

四氧化三钴（Co₃O₄）是一种p型半导体，可作为气体传感材料。非金属硼（B）具有吸电子特性，将其与p型半导体气敏材料进行掺杂，可增加材料的空穴载流子浓度，从而提高材料的气敏性能。本文以六水合硝酸钴Co(NO₃)₂·6H₂O]、硼酸（H₃BO₃）和尿素CO(NH₂)₂]为原料，采用低温一步水热法成功制备了B掺杂Co₃O₄海胆状微球。通过X射线衍射仪（XRD）、扫描电镜（SEM）、透射电镜（TEM）、X射线光电子能谱仪（XPS）和拉曼光谱仪（Raman）对掺杂B前后的Co₃O₄进行结构表征，探究B掺杂对其气敏性能的影响。结果表明：B掺杂对Co₃O₄材料的气敏性能有明显的强化作用。当掺杂摩尔比为Co∶B=8∶1时，B-Co₃O₄对1×10⁵μg/L乙醇的最佳工作温度为180℃，灵敏度响应达到26.8，是相同条件下纯Co₃O₄的4.4倍。B-Co₃O₄在较低的工作温度下，具有良好的灵敏度、选择性和稳定性，是一种性能优良的气敏材料。

Preparation of boron doped Co3O4 sea urchin-like microspheres and its gas sensing enhancement mechanism for ethanol

Cobalt oxide (Co₃O₄) is a typical p-type semiconductor and can be used as a gas sensing material. The gas-sensing properties of Co₃O₄ can be improved by doping non-metallic boron (B) due to the absorbing electron characteristics of boron(B) that makes hole concentration of Co₃O₄ increase. In this paper, B-doped Co₃O₄ microspheres with sea urchin morphology were successfully prepared by low-temperature one-step hydrothermal method using cobalt nitrate hexahydrate Co(NO₃)₂·6H₂O], boric acid (H₃BO₃) and urea Co(NH₂)₂] as raw materials. The structures and morphologies of Co₃O₄ before and after boron doping were characterized by various spectra, and the gas sensing properties to ethanol were examined. The results show that boron doping significantly enhances the gas sensing properties of Co₃O₄. When the doped molar ratio is Co∶B=8∶1, the doped Co₃O₄ not only exhibits high response of 26.8 in 1×10⁵μg/L ethanol, which is 4.4 times higher than that of pure Co₃O₄, but also good selectivity and stability at the optimal working temperature of 180℃. So, the B doped Co₃O₄ is a promising gas sensing material for detection of VOCs.