【摘要】：TiO2的表面形貌對于其光催化性能有著至關(guān)重要的影響。本研究中,我們通過水熱合成法制備了一種新型的銳鈦礦納米二氧化鈦,在NH4F和HF的作用下,高活性{111}面占主導(dǎo)地位。本研究的主要進展通過調(diào)節(jié)NH4+和F-的摩爾比例,可以直接控制二氧化鈦暴露的晶面。當(dāng)NH4+和F-的摩爾比達到1:2,能夠得到{111}面為主要暴露面的銳鈦礦二氧化鈦。當(dāng)只加入氨水或HF時,得到的納米銳鈦礦二氧化鈦暴露面分別為{101}面或{001}面。這樣的{111}面暴露的納米二氧化鈦顯示出優(yōu)異的光催化活性,這種活性是{001}面的片狀二氧化鈦和商用的德固賽P25的2-3倍,也就證實了{111}面比{001}和{101}面具有更高的光催化活性。原子在的表面是不飽和Ti5c、Ti3c和O2c模式產(chǎn)生更高的吸附和降解能力。同時,我們還研究了用這種方法所制備的不同晶面暴露的納米銳鈦礦二氧化鈦的光催化選擇性能。通過上述水熱合成法得到{101}面、{111}面和{001}面為主要暴露面的銳鈦礦二氧化鈦后,煅燒去除表面吸附的原子。結(jié)果顯示,{101}面暴露的二氧化鈦結(jié)合有殘留的N,并且以不飽和N3c的模式存在,在對MO和MB的混合溶液進行光催化選擇性實驗中表現(xiàn)出對MO的選擇性降解。而{111}面和{001}面暴露的銳鈦礦二氧化鈦表現(xiàn)出對MB的光催化選擇性。這證明了光催化選擇性可以被不同的主導(dǎo)晶面影響。經(jīng)過進一步的分析,我們得出{001}面和{111}面表面上存在不飽和的O2c,這樣的結(jié)合模式提高了吸附選擇性,在光催化選擇實驗中表現(xiàn)出的對MB的選擇性。在{111}表面上,存在的都是不飽和O2c,這也導(dǎo)致{111}面更好的光催化選擇性。我們的研究提供了一種通過水熱法進一步探索納米材料制備的方法,同時希望發(fā)展一個新的光催化選擇的方式,提供一種更深層次的對不同晶面的二氧化鈦的理解。并且,這項研究的結(jié)果也可以應(yīng)用在光催化、太陽能蓄電池和傳感器等領(lǐng)域。
[Abstract]:The surface morphology of TiO2 plays an important role in the photocatalytic performance. In this study, we prepared a new anatase nano-TiO _ 2 by hydrothermal synthesis. Under the action of NH _ 4F and HF, the highly active {111} surface dominated. By adjusting the molar ratio of NH _ 4 and F _ -, the crystal faces of TIO _ 2 exposed can be directly controlled. When the molar ratio of NH4 to F- reaches 1: 2, anatase TIO _ 2 with {111} plane as the main exposed surface can be obtained. When only ammonia or HF was added, the exposed surfaces of anatase were {101} and {001}, respectively. The nanometer TIO _ 2 exposed to the {111} surface shows excellent photocatalytic activity, which is 2-3 times higher than that of the {001} flake titanium dioxide and the commercial Degussi P25. It is also confirmed that the {111} face has higher photocatalytic activity than the {001} and {101} masks. On the surface of the atoms, the unsaturated Ti5cTi3c and O2c modes produce higher adsorption and degradation ability. At the same time, we also studied the photocatalytic selectivity of nanocrystalline anatase TIO _ 2 prepared by this method. Anatase TIO _ 2 with {101}, {111} and {001} faces as main exposed surfaces was obtained by hydrothermal synthesis, and the atoms adsorbed on the surface were removed by calcination. The results show that titanium dioxide exposed to {101} surface binds with residual N, and exists in the mode of unsaturated N3c. The selective degradation of MO in the mixed solution of MO and MB is demonstrated in the photocatalytic selectivity experiment. The anatase exposed to {111} and {001} surfaces showed photocatalytic selectivity to MB. It is proved that the photocatalytic selectivity can be affected by different dominant crystal planes. After further analysis, we found that there are unsaturated O _ 2C on the {001} and {111} surfaces, which enhances the adsorption selectivity and exhibits the selectivity to MB in the photocatalytic selection experiment. On the {111} surface, unsaturated O _ 2C exists, which also leads to better photocatalytic selectivity on {111} surface. Our research provides a method for further exploring the preparation of nanomaterials by hydrothermal method. At the same time, we hope to develop a new way of photocatalytic selection and provide a deeper understanding of titanium dioxide with different crystal faces. The results can also be used in photocatalysis, solar batteries and sensors.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ134.11;O643.36

【共引文獻】

相關(guān)期刊論文 前1條

1 何琴;黃保軍;李穎穎;法文君;;生物模板法制備微納米二氧化錫[J];化工新型材料;2012年05期

相關(guān)碩士學(xué)位論文 前2條

1 滿麗瑩;微波溶劑熱制備納米結(jié)構(gòu)SnO_2及其氣敏性研究[D];濟南大學(xué);2012年

2 韓麗仙;錫基微納米晶體的制備及其性能的研究[D];上海師范大學(xué);2013年

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本文編號：2131467