【摘要】：能源危機(jī)和環(huán)境惡化是當(dāng)前人類社會所面臨的兩個重大問題,采用太陽光進(jìn)行光催化全分解水產(chǎn)氫產(chǎn)氧是解決上述問題的有效途徑之一。由于廉價易得以及穩(wěn)定無毒,目前大量使用二氧化鈦光催化劑,但存在吸收光譜較窄、太陽能利用率低、電子與空穴復(fù)合幾率高等缺點(diǎn),同時光催化產(chǎn)氫往往需要添加有機(jī)物(如甲醇)作為犧牲劑消耗多余的光生空穴,導(dǎo)致成本增加,而且缺少對光電催化全分解水的探究。WO_3作為一種常見的半導(dǎo)體光催化劑,帶隙為2.5-2.8eV,能夠捕獲近12%的太陽光譜,廣泛應(yīng)用于吸附,催化,儲能及敏感器件等領(lǐng)域。圍繞著半導(dǎo)體光催化劑WO_3如何有效的增強(qiáng)電子空穴分離,如何構(gòu)建高質(zhì)量的異質(zhì)結(jié)界面提高光催化活性等開展了以下幾方面的工作。1、WO_3材料作為一個很好的析氧氣材料,可與析氫反應(yīng)相結(jié)合,從而形成對水的全分解。本章我們采用氣相刻蝕的方法處理W片從而獲得WO_3納米電極材料,并在可見光的照射下探究其光電催化分解水的性能。同時探究了氣相刻蝕溫度,時間和HF濃度對電極材料表面結(jié)構(gòu)形貌與全分解水活性影響,發(fā)現(xiàn)采用4MHF作為刻蝕劑,150℃條件下刻蝕24h獲得的WO_3納米電極材料的光電催化全分解的活性最好,并結(jié)合XRD、SEM以及相關(guān)電化學(xué)表征對WO_3電極材料的表面物理化學(xué)性質(zhì)與光電催化性能的關(guān)系進(jìn)行了探究。2、以上述最佳WO_3電極材料作為基底,通過旋Q肂iVO_4納米晶體獲得BiVO_4/WO_3復(fù)合電極材料。從而構(gòu)建復(fù)合型光電催化電極材料,增加載流子的密度和提高了光生電子-空穴利用效率,最終提高光電催化分解水活性。本章采用硝酸鉍與偏釩酸銨混合先制備出釩酸鉍,然后再用旋轉(zhuǎn)鍍膜儀將釩酸鉍前驅(qū)體旋Q玫絎O_3納米材料上,經(jīng)過煅燒形成BiVO_4/WO_3復(fù)合材料,并探究了其光電催化分解水性能。3、將已經(jīng)合成好的WO_3電極材料分別在200℃條件下,不同氛圍(真空,氫氣,氮?dú)?下煅燒,得到含有氧空位的光電催化電極材料,研究發(fā)現(xiàn)在氫氣氛圍下處理的獲得的電極具有最佳的光電催化分解水活性。這是因?yàn)樵跉錃夥諊绿幚頃纬裳蹩瘴?產(chǎn)生局部共振效應(yīng),從而增加了電子和空穴的分離效率。
[Abstract]:Energy crisis and environmental deterioration are two major problems facing human society at present. One of the effective ways to solve these problems is the photocatalytic decomposition of hydrogen and oxygen in aquatic products by solar light. At present, titanium dioxide photocatalyst is widely used because of its low cost and stability, but it has some disadvantages, such as narrow absorption spectrum, low utilization of solar energy, high probability of recombination of electron and hole, etc. At the same time, the addition of organic compounds (such as methanol) as a sacrificial agent to produce hydrogen in photocatalysis often requires the consumption of excess photogenerated holes, which leads to the increase of cost, and the lack of research on the total decomposition of water in photocatalysis. WO_3 is a common semiconductor photocatalyst. The band gap is 2.5-2.8 EV, which can capture nearly 12% of the solar spectrum. It is widely used in the fields of adsorption, catalysis, energy storage and sensitive devices. The following work has been done on how to effectively enhance the electron hole separation of semiconductor photocatalyst WO_3 and how to construct a high quality heterogeneous boundary surface to improve photocatalytic activity. 1 WO / WO _ 3 material is a good oxygen evolution material. It can be combined with hydrogen evolution reaction to form the total decomposition of water. In this chapter, we use gas phase etching method to treat W wafer to obtain WO_3 nanocrystalline electrode material, and investigate its photocatalytic decomposition of water under visible light irradiation. At the same time, the effects of gas etching temperature, time and HF concentration on the surface morphology and total decomposition water activity of electrode materials were investigated. It was found that the photocatalytic decomposition activity of WO_3 nano-electrode materials obtained by etching at 150 鈩，

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