本文選題：(NH4)2Ta2O3F6納米管 + Ta2O5納米片��； 參考：《哈爾濱師范大學(xué)》2015年碩士論文

【摘要】：鉭基納米光催化材料具有較高的導(dǎo)帶位置,其光生電子有較強的還原能力,因此,使其在光催化分解水制取氫氣領(lǐng)域有著非常廣闊的前景。本文采用水熱法和煅燒法成功制得了(NH4)2Ta2O3F6納米管、Ta2O5納米片、Na2Ta2O6和NaTaO3納米粒子光催化劑。并研究了負載貴金屬Pt對(NH4)2Ta2O3F6納米管和Ta2O5納米片光催化制氫活性的影響。本文運用SEM、TEM、EDS、XRD、BET、XPS和UV-Vis DRS等測試方法,討論了所制備光催化劑的形貌、大小、元素組成、晶體結(jié)構(gòu)以及對光譜的響應(yīng)區(qū)域,并對其光催化分解水制取氫氣的活性進行了研究和探討。首先,采用水熱合成法,在不同的水熱條件下制得了形貌不同的鉭基納米材料。實驗結(jié)果表明,在HF為0.2 mL,水熱溫度180℃,水熱時間為24 h這一條件下,合成的(NH4)2Ta2O3F6納米管較長,管徑均一,且為暴露{202}晶面的斜方晶系(NH4)2Ta2O3F6單晶半導(dǎo)體材料。DRS測試顯示,(NH4)2Ta2O3F6納米管在紫外光區(qū)域有很強的吸收,且光催化劑的禁帶寬度是3.67 eV。同時,對樣品進行了9個小時的制氫循環(huán)穩(wěn)定性測試,可知納米管有很好的制氫穩(wěn)定性。為了提高(NH4)2Ta2O3F6納米管的光催化制氫活性,運用了光化學(xué)還原法,在(NH4)2Ta2O3F6納米管的表面上負載了Pt貴金屬。實驗結(jié)果表明,當(dāng)Pt的負載量為0.6%時,其光催化分解水制氫活性最高,是未負載(NH4)2Ta2O3F6納米管的1.46倍。其次,以(NH4)2Ta2O3F6納米管為前驅(qū)體,在不同的煅燒條件下對樣品進行了煅燒,從SEM的分析結(jié)果可知,在300℃煅燒2 h的條件下,制備出了厚度均一,棱角清晰的納米片狀結(jié)構(gòu)的樣品。由XRD分析結(jié)果表明,所制得的納米片為斜方晶系的Ta2O5,并且該樣品有很好的結(jié)晶度。在紫外光照射下,對制備的Ta2O5納米片和商業(yè)Ta2O5的光催化制氫活性和循環(huán)穩(wěn)定性進行了測試,實驗結(jié)果表明,Ta2O5納米片的制氫活性是商業(yè)Ta2O5的3倍,且兩種Ta2O5均具有很好的制氫穩(wěn)定性。此外,對Ta2O5納米片進行了貴金屬Pt的負載,并對其在不同體系中的可見光催化制氫活性進行了測試。最后,運用水熱合成法,在不同的NaOH濃度下,制備出了Na2Ta2O6和NaTa O3納米粒子光催化劑。SEM分析顯示,所制備的樣品均為尺寸很小的納米粒子。XRD分析結(jié)果表明,當(dāng)NaOH濃度由0.5 mol/L增大到1.0 mol/L時,所制備的樣品由Na2Ta2O6轉(zhuǎn)變?yōu)镹aTaO3。同時,對所制備的納米粒子進行了光催化分解水制氫的測試。測試結(jié)果顯示,立方晶型Na2Ta2O6的制氫活性比斜方晶系NaTaO3的制氫活性小很多。且當(dāng)NaOH濃度為2.0 mol/L時,所制備的NaTaO3納米粒子的制氫活性最高,為1124.72 umol/g。
[Abstract]:Tantalum based nanocrystalline photocatalytic materials have high conduction band position and strong reduction ability of photogenerated electrons. Therefore, tantalum nanocrystalline photocatalytic materials have a very broad prospect in the field of photocatalytic decomposition of water to produce hydrogen.In this paper, NH _ 4N _ 2TA _ 2O _ 3F _ 6 nanotubes, Na _ 2TA _ 2O _ 6 and NaTaO3 nanoparticles photocatalysts were successfully prepared by hydrothermal method and calcination method.The effect of supported noble metal Pt on the photocatalytic activity of NH _ 4N _ 2TA _ 2O _ 3F _ 6 nanotubes and Ta2O5 nanoparticles for hydrogen production was investigated.In this paper, the morphology, size, elemental composition, crystal structure and spectral response region of the prepared photocatalyst were discussed by means of UV-Vis DRS and UV-Vis DRS. The photocatalytic activity of the photocatalyst for the preparation of hydrogen from water was studied and discussed.Firstly, tantalum based nanomaterials with different morphologies were prepared by hydrothermal synthesis under different hydrothermal conditions.The experimental results show that under the conditions of 0.2 mL HF, 180 鈩，

本文編號：1748208