新型光催化電極材料的合成及其光電催化性能的探究
發(fā)布時(shí)間:2018-04-04 03:36
本文選題:異相結(jié) 切入點(diǎn):光解水制氫 出處:《上海師范大學(xué)》2017年碩士論文
【摘要】:能源危機(jī)以及環(huán)境污染問題一直是制約當(dāng)前人類社會(huì)發(fā)展的兩個(gè)重大問題,使用清潔能源代替化石能源,構(gòu)筑可再生資源,代替化石能源,是解決上述問題的有效途徑之一。太陽能作為一種取之不盡、用之不竭的清潔能源,能很好的為人類社會(huì)提供能源動(dòng)力,但是太陽能利用率低、使用成本高,間歇性的能源供應(yīng)等問題限制了太陽能的廣泛應(yīng)用。而光電催化技術(shù),能夠有效地將太陽能儲(chǔ)存于化學(xué)物質(zhì)之中,應(yīng)用于工業(yè)生產(chǎn),其中,氫能被學(xué)者廣泛地認(rèn)為是一種無污染、儲(chǔ)能高的新能源,是21世紀(jì)最有潛力的替代能源。所以光電催化制備氫氣獲得了廣泛地研究。半導(dǎo)體光催化技術(shù)可直接利用太陽能分解水制備氫氣,而其中TiO_2作為典型半導(dǎo)體,獲得了廣泛的研究。但是光吸收范圍窄,光生電子和空穴復(fù)合速率高等問題限制了其實(shí)際的應(yīng)用。為了解決這些問題,我們目前采用的手段有金屬修飾,半導(dǎo)體復(fù)合,異相結(jié)等光催化摻雜技術(shù),結(jié)合電化學(xué)技術(shù),實(shí)現(xiàn)光電催化性能提升的效果。在本文中,我們主要的研究內(nèi)容如下:(1)結(jié)合銳鈦礦相的TiO_2和金紅石相的TiO_2,其禁帶寬度,導(dǎo)帶和價(jià)帶的不同,運(yùn)用水熱、醇熱的制備方法,在金紅石相的TiO_2納米棒陣列FTO電極上,負(fù)載小顆粒的銳鈦礦相TiO_2納米點(diǎn),構(gòu)筑異相結(jié)電極材料,系統(tǒng)地研究了材料在紫外光下,分解水產(chǎn)生氫氣的光電催化性能。通過該電極作為光陽極,一定程度地提高了光電轉(zhuǎn)化產(chǎn)氫的效率。(2)運(yùn)用簡單的一步水熱的辦法,在銅泡沫的基底上,構(gòu)筑金紅石相的TiO_2納米棒,通過TiCl3作為前驅(qū)液,以金屬銅作為良好的導(dǎo)電子材料,提供了一種有效促使電子空穴分離的路徑。另一方面,銅泡沫所形成的的多孔多基底面積,為陽極的反應(yīng)提供了有效的接觸面,可以很大程度提高光催化產(chǎn)氫的速率,銅泡沫宏觀的多空結(jié)構(gòu),利于單位面積光的反復(fù)照射和利用,避免了單位平面的堆垛催化劑,增大了納米尺寸。(3)運(yùn)用簡單的浸漬、水熱的方法,將銅泡沫形成Cu_2O陣列,并在之后,進(jìn)行TiO_2納米薄片的包裹,形成Branched形貌,這一方面保護(hù)了Cu_2O陣列,另一方面,也是P型Cu_2O電子傳導(dǎo)的重要途徑。我們將該電極作光陰極,該電極具有良好的CO_2還原選擇性,能夠高效地將CO_2還原為甲酸。(4)通過浸漬的方法,將C_(60)分散到甲苯溶液中,并與g-C_3N_4的前驅(qū)物三聚氰胺進(jìn)行均勻混合,并在之后形成C_(60)分散的g-C_3N_4,C_(60)作為一種良好的電子傳導(dǎo)劑,能夠很好地將電子從C_3N_4上傳輸?shù)紺_(60)上,從而有效地拉動(dòng)了電子,增強(qiáng)g-C_3N_4光催化性能。
[Abstract]:Energy crisis and environmental pollution are two major problems restricting the development of human society. The use of clean energy instead of fossil energy, the construction of renewable resources and the replacement of fossil energy is one of the effective ways to solve these problems.Solar energy, as an inexhaustible clean energy, can provide energy power for human society, but the low utilization rate of solar energy, high cost of use, intermittent energy supply and other problems limit the wide application of solar energy.Photocatalytic technology can effectively store solar energy in chemical materials and be used in industrial production. Among them, hydrogen energy is widely regarded by scholars as a new energy source with no pollution and high energy storage, which is the most potential alternative energy in the 21st century.Therefore, photocatalytic preparation of hydrogen has been widely studied.Semiconductor photocatalytic technology can directly use solar energy to decompose water to produce hydrogen, and TiO_2, as a typical semiconductor, has been widely studied.However, its practical application is limited by the narrow optical absorption range and high recombination rate of photogenerated electrons and holes.In order to solve these problems, we have adopted the methods of metal modification, semiconductor recombination, heterogeneous junction and other photocatalytic doping technology, combined with electrochemical technology, to achieve the effect of improving the photocatalytic performance.In this paper, the main contents of our research are as follows: (1) in combination with anatase phase TiO_2 and rutile phase TiO2, the band gap, conduction band and valence band are different, using hydrothermal and alcohol heat preparation methods, on the TiO_2 nanorod array FTO electrode of rutile phase.The photocatalytic properties of anatase phase TiO_2 nanowires loaded with small particles to produce hydrogen by decomposing water under ultraviolet light have been systematically studied by constructing heterogeneous junction electrode materials.By using the electrode as a photoanode, the efficiency of photoconversion for hydrogen production has been improved to a certain extent. A simple one-step hydrothermal method has been used to construct rutile TiO_2 nanorods on the copper foam substrate and TiCl3 as the precursor solution.Metal copper as a good electron conducting material provides an effective path to the separation of electron holes.On the other hand, the porous multi-substrate area formed by the copper foam provides an effective contact surface for the anodic reaction, which can greatly increase the rate of photocatalytic hydrogen production, and the macroporous structure of the copper foam.It is advantageous to the repeated irradiation and utilization of light per unit area, avoids the stacking catalyst in unit plane, and increases the nanometer size. (3) the copper foam is formed into Cu_2O array by simple impregnation, hydrothermal method, and then,The Branched morphology is formed by encapsulating the TiO_2 nanocrystals, which protects the Cu_2O array on the one hand, and on the other hand, it is also an important way of conducting P-type Cu_2O electrons.We used the electrode as a photocathode. The electrode has good CO_2 reduction selectivity, and can efficiently reduce CO_2 to formic acid. 4) by impregnation, Che 60) is dispersed into toluene solution and mixed evenly with melamine, the precursor of g-C_3N_4.As a good electron conduction agent, it can transport electrons from C_3N_4 to CSC60), thus effectively pulling electrons and enhancing the photocatalytic performance of g-C_3N_4.
【學(xué)位授予單位】:上海師范大學(xué)
【學(xué)位級(jí)別】:碩士
【學(xué)位授予年份】:2017
【分類號(hào)】:O643.36
,
本文編號(hào):1708193
本文鏈接:http://sikaile.net/kejilunwen/huaxue/1708193.html
最近更新
教材專著