【摘要】：伴隨環(huán)境污染問題日益加劇,借助半導(dǎo)體材料實(shí)現(xiàn)光能的光電轉(zhuǎn)化在催化及環(huán)境領(lǐng)域引起廣泛關(guān)注。本文借助電化學(xué)方法快速高效地合成不同沉積時(shí)間納米赤鐵礦薄膜電極。X射線衍射(XRD)、Raman光譜測試表明其成分為赤鐵礦物相;原子力顯微鏡(AFM)觀測顆粒尺寸約52.1(±1.48)nm×50.5(±1.49)nm,表面高度起伏分布于70~100 nm,且分布特征符合正態(tài)分布規(guī)律。紫外可見漫反射吸收譜顯示電極可顯著吸收350~600 nm波長范圍可見光,計(jì)算得禁帶寬度約2.0~2.1 e V。光電化學(xué)實(shí)驗(yàn)光電流密度-時(shí)間曲線及電流-電壓曲線表明電極有良好的可見光光電催化活性,且反應(yīng)符合Langmuir-Hinshelwood多相反應(yīng)動(dòng)力學(xué)模型。進(jìn)一步選取效果較顯著的沉積時(shí)間10 min電極研究其光電催化降解苯酚活性,0.65 V vs.SCE(飽和甘汞電極)恒電勢光照條件下6 h苯酚降解率達(dá)62%,擬合一級(jí)動(dòng)力學(xué)反應(yīng)模型可知,反應(yīng)速率常數(shù)k為0.16 h-1(R2=0.996)。綜上,本文研究結(jié)果顯示電化學(xué)法簡單高效合成的納米赤鐵礦具有良好半導(dǎo)體性能且能夠可見光光電催化降解苯酚等有機(jī)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 (鹵1.48) nm 脳 50.5 (鹵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.
【作者單位】： 造山帶與地殼演化教育部重點(diǎn)實(shí)驗(yàn)室礦物環(huán)境功能北京市重點(diǎn)實(shí)驗(yàn)室北京大學(xué)地球與空間科學(xué)學(xué)院;
【基金】：國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃“973計(jì)劃”(2014CB846001) 國家自然科學(xué)基金(41230103,41522201,41402032)~~
【分類號(hào)】：P579;X505
，

本文編號(hào)：2333701