纳米赤铁矿电极光电催化特性及苯酚降解活性研究
发布时间：2018-11-15 15:36
【摘要】：伴随环境污染问题日益加剧,借助半导体材料实现光能的光电转化在催化及环境领域引起广泛关注。本文借助电化学方法快速高效地合成不同沉积时间纳米赤铁矿薄膜电极。X射线衍射(XRD)、Raman光谱测试表明其成分为赤铁矿物相;原子力显微镜(AFM)观测颗粒尺寸约52.1(±1.48)nm×50.5(±1.49)nm,表面高度起伏分布于70~100 nm,且分布特征符合正态分布规律。紫外可见漫反射吸收谱显示电极可显著吸收350~600 nm波长范围可见光,计算得禁带宽度约2.0~2.1 e V。光电化学实验光电流密度-时间曲线及电流-电压曲线表明电极有良好的可见光光电催化活性,且反应符合Langmuir-Hinshelwood多相反应动力学模型。进一步选取效果较显著的沉积时间10 min电极研究其光电催化降解苯酚活性,0.65 V vs.SCE(饱和甘汞电极)恒电势光照条件下6 h苯酚降解率达62%,拟合一级动力学反应模型可知,反应速率常数k为0.16 h-1(R2=0.996)。综上,本文研究结果显示电化学法简单高效合成的纳米赤铁矿具有良好半导体性能且能够可见光光电催化降解苯酚等有机污染物。
[Abstract]:With the increasing problem of environmental pollution, photovoltaic conversion of light energy by semiconductor materials has attracted wide attention in the field of catalysis and environment. Nanocrystalline hematite thin film electrodes were synthesized rapidly and efficiently by electrochemical method. X-ray diffraction (XRD), Raman) spectra showed that the nanocrystalline hematite film electrode was composed of hematite phase. The particle size observed by atomic force microscope (AFM) is about 52.1 (卤1.48) nm 脳 50.5 (卤1.49) nm,. The surface height fluctuation of atomic force microscope (AFM) is about 70 ~ 100 nm, and the distribution characteristics are in accordance with the normal distribution rule. The UV-Vis diffuse reflectance spectroscopy shows that the electrode can absorb visible light significantly in the wavelength range of 350 ~ 600 nm, and the bandgap is calculated to be about 2.0 ~ (2.1) EV. The photocurrent density-time curves and current-voltage curves of photochemical experiments show that the electrode has good photocatalytic activity of visible light, and the reaction accords with the kinetic model of Langmuir-Hinshelwood multiphase reaction. The photocatalytic degradation of phenol on 10 min electrode with remarkable deposition time was further studied. The degradation rate of phenol reached 62g / h under the constant potential illumination of 0.65 V vs.SCE (saturated calomel electrode). According to the first-order kinetic model, the reaction rate constant k is 0.16 h ~ (-1) (R _ 2 ~ (2 +) -0.996). In summary, the results show that nanocrystalline hematite synthesized by electrochemical method has good semiconductor properties and can be used for photocatalytic degradation of phenol and other organic pollutants in visible light.
【作者单位】： 造山带与地壳演化教育部重点实验室矿物环境功能北京市重点实验室北京大学地球与空间科学学院;
【基金】：国家重点基础研究发展计划“973计划”(2014CB846001) 国家自然科学基金(41230103,41522201,41402032)~~
【分类号】：P579;X505
，
本文编号：2333701
[Abstract]:With the increasing problem of environmental pollution, photovoltaic conversion of light energy by semiconductor materials has attracted wide attention in the field of catalysis and environment. Nanocrystalline hematite thin film electrodes were synthesized rapidly and efficiently by electrochemical method. X-ray diffraction (XRD), Raman) spectra showed that the nanocrystalline hematite film electrode was composed of hematite phase. The particle size observed by atomic force microscope (AFM) is about 52.1 (卤1.48) nm 脳 50.5 (卤1.49) nm,. The surface height fluctuation of atomic force microscope (AFM) is about 70 ~ 100 nm, and the distribution characteristics are in accordance with the normal distribution rule. The UV-Vis diffuse reflectance spectroscopy shows that the electrode can absorb visible light significantly in the wavelength range of 350 ~ 600 nm, and the bandgap is calculated to be about 2.0 ~ (2.1) EV. The photocurrent density-time curves and current-voltage curves of photochemical experiments show that the electrode has good photocatalytic activity of visible light, and the reaction accords with the kinetic model of Langmuir-Hinshelwood multiphase reaction. The photocatalytic degradation of phenol on 10 min electrode with remarkable deposition time was further studied. The degradation rate of phenol reached 62g / h under the constant potential illumination of 0.65 V vs.SCE (saturated calomel electrode). According to the first-order kinetic model, the reaction rate constant k is 0.16 h ~ (-1) (R _ 2 ~ (2 +) -0.996). In summary, the results show that nanocrystalline hematite synthesized by electrochemical method has good semiconductor properties and can be used for photocatalytic degradation of phenol and other organic pollutants in visible light.
【作者单位】： 造山带与地壳演化教育部重点实验室矿物环境功能北京市重点实验室北京大学地球与空间科学学院;
【基金】：国家重点基础研究发展计划“973计划”(2014CB846001) 国家自然科学基金(41230103,41522201,41402032)~~
【分类号】：P579;X505
，
本文编号：2333701
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