分子催化剂修饰的钒酸铋光阳极的制备与光电性能研究
发布时间：2018-10-05 16:19
【摘要】：利用太阳能驱动水分解生产清洁化学燃料-氢气,被认为是减轻化石燃料燃烧引起的环境问题,满足全球日益增长的能源需求的有效途径。在人工光合作用体系中,水分解反应是提供质子和电子的关键步骤,是制约太阳能转化的瓶颈。在水分解反应中影响太阳能燃料合成效率的主要限制因素包括:ⅰ)光吸收,ⅱ)电荷分离和运输, ⅲ)表面化学反应。在光敏半导体上负载可以改善电子电荷分离或可以充当空穴受体的助催化剂是解决这些难题的有效手段。本文以价格低廉的钴金属为原料,合成了带乙烯基的钴立方烷水氧化分子催化剂Col,将Col在FTO和BiVO_4上以电化学聚合的方式负载,制备了poly-1/FTO复合阳极和poly-1/BiVO_4光阳极。对于poly-1/FTO电极来说,在外加电压为1.2VvsAg/AgCl时,电流密度可达到4mA/cm~2。经过长时间电解后,依然有将近2 mA/cm~2的电流密度存在。电极的法拉第效率可以达到84.8%。对于 poly-1/BiVO_4 光阳极,在 0.6 V vs Ag/AgCl 偏压和 100 mW/cm~2 光照下,poly-1/BiVO_4光阳极比BiVO_4光电流密度提高了 8倍。法拉第效率由BiVO_4的31.4 %提高至59.8 %。入射单色光子-电子转化效率(IPCE)由BiVO_4的5 %提高至了 23 %,光阳极的空穴注入效率由BiVO_4的20 %以下提高至了 80 %以上,而poly-1/BiVO_4相对于BiVO_4的电荷分离效率在1.23 V vs RHE处接近90 %。本文还改进方法制备了 BiVO_4半导体材料,并制备了 AuNPs修饰的纳米多孔BiVO_4光电阳极,利用AuNPs的等离子体效应来增强复合电极的光响应。将制备的AuNPs/BiVO_4电极进行光电化学测试,测试结果表明,与单独的BiVO_4相比,AuNPs/BiVO_4复合电极光催化分解水的光电流有明显提高,说明金的等离子体效应有助于BiVO_4和金的电荷传输。合成了巯基修饰的联吡啶钌基分子催化剂Ru1,通过AuNPs和巯基之间的化学吸附作用,将催化剂负载于AuNPs/BiVO_4电极表面。对Ru1/AuNPs/BiVO_4阳极的光催化水氧化的性能进行了深入的研究,在100 mW/cm~2光照条件下,外加0.62 V vs Ag/AgCl偏压,Ru1/AuNPs/BiVO_4光阳极电流密度可达2 mA/cm~2,比BiVO_4高4倍,比AuNPs/BiVO_4的光电流高1.5倍,并且测试时间内无明显的电流下降,得到了相对稳定的恒定电流。
[Abstract]:The use of solar energy to drive water decomposition to produce clean chemical fuel-hydrogen is considered to be an effective way to alleviate the environmental problems caused by fossil fuel combustion and to meet the increasing global energy demand. In artificial photosynthesis, water decomposition is the key step to provide protons and electrons, and is the bottleneck of solar energy conversion. The main factors limiting the efficiency of solar fuel synthesis in water decomposition include: I) light absorption, II) charge separation and transport, and III) surface chemical reaction. Loading on Guang Min semiconductor can improve the separation of electron charge or act as a catalyst for hole receptor is an effective way to solve these problems. In this paper, the low cost cobalt metal was used as the raw material to prepare poly-1/FTO composite anode and poly-1/BiVO_4 photoanode by electrochemical polymerization of Col on FTO and BiVO_4 supported by Col, a molecular catalyst of cobalt cubic alkane water oxidation with vinyl group. For the poly-1/FTO electrode, the current density can reach 4 Ma / cm ~ (2) when the applied voltage is 1.2VvsAg/AgCl. After a long period of electrolysis, there is still a current density of nearly 2 mA/cm~2. The Faraday efficiency of the electrode can reach 84.8. For the poly-1/BiVO_4 photoanode, the photocurrent density of the poly-1 / Bivos _ 4 photoanode is 8 times higher than that of the BiVO_4 photoanode under 0. 6 V vs Ag/AgCl bias and 100 mW/cm~2 illumination. Faraday efficiency increased from 31.4% of BiVO_4 to 59.8%. The incident monochromatic photon electron conversion efficiency (IPCE) is increased from 5% of BiVO_4 to 23%, the hole injection efficiency of photoanode is increased from less than 20% of BiVO_4 to more than 80%, and the charge separation efficiency of poly-1/BiVO_4 relative to BiVO_4 is close to 90% at 1.23 V vs RHE. In this paper, BiVO_4 semiconductor materials and AuNPs modified nano-porous BiVO_4 photoanode were prepared. The photoresponse of the composite electrode was enhanced by using the plasma effect of AuNPs. The photochemical test of the prepared AuNPs/BiVO_4 electrode shows that the photocatalytic photocurrent of the au / ANPs / BiVO _ 4 composite electrode is significantly higher than that of the single BiVO_4 electrode, indicating that the plasma effect of gold is helpful to the charge transport of BiVO_4 and gold. Mercapto modified bipyridine ruthenium based catalyst Ru1, was synthesized by chemisorption between AuNPs and sulfhydryl. The catalyst was supported on the surface of AuNPs/BiVO_4 electrode. The photocatalytic water oxidation of Ru1/AuNPs/BiVO_4 anode was studied. Under 100 mW/cm~2 illumination, the current density of the photoanode was 4 times higher than that of BiVO_4 and 1.5 times higher than that of AuNPs/BiVO_4 under 0.62 V vs Ag/AgCl bias voltage Ru1 / AuNPs / BiVO4. And there is no obvious current drop in the test time, and a relatively stable constant current is obtained.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O646.5
[Abstract]:The use of solar energy to drive water decomposition to produce clean chemical fuel-hydrogen is considered to be an effective way to alleviate the environmental problems caused by fossil fuel combustion and to meet the increasing global energy demand. In artificial photosynthesis, water decomposition is the key step to provide protons and electrons, and is the bottleneck of solar energy conversion. The main factors limiting the efficiency of solar fuel synthesis in water decomposition include: I) light absorption, II) charge separation and transport, and III) surface chemical reaction. Loading on Guang Min semiconductor can improve the separation of electron charge or act as a catalyst for hole receptor is an effective way to solve these problems. In this paper, the low cost cobalt metal was used as the raw material to prepare poly-1/FTO composite anode and poly-1/BiVO_4 photoanode by electrochemical polymerization of Col on FTO and BiVO_4 supported by Col, a molecular catalyst of cobalt cubic alkane water oxidation with vinyl group. For the poly-1/FTO electrode, the current density can reach 4 Ma / cm ~ (2) when the applied voltage is 1.2VvsAg/AgCl. After a long period of electrolysis, there is still a current density of nearly 2 mA/cm~2. The Faraday efficiency of the electrode can reach 84.8. For the poly-1/BiVO_4 photoanode, the photocurrent density of the poly-1 / Bivos _ 4 photoanode is 8 times higher than that of the BiVO_4 photoanode under 0. 6 V vs Ag/AgCl bias and 100 mW/cm~2 illumination. Faraday efficiency increased from 31.4% of BiVO_4 to 59.8%. The incident monochromatic photon electron conversion efficiency (IPCE) is increased from 5% of BiVO_4 to 23%, the hole injection efficiency of photoanode is increased from less than 20% of BiVO_4 to more than 80%, and the charge separation efficiency of poly-1/BiVO_4 relative to BiVO_4 is close to 90% at 1.23 V vs RHE. In this paper, BiVO_4 semiconductor materials and AuNPs modified nano-porous BiVO_4 photoanode were prepared. The photoresponse of the composite electrode was enhanced by using the plasma effect of AuNPs. The photochemical test of the prepared AuNPs/BiVO_4 electrode shows that the photocatalytic photocurrent of the au / ANPs / BiVO _ 4 composite electrode is significantly higher than that of the single BiVO_4 electrode, indicating that the plasma effect of gold is helpful to the charge transport of BiVO_4 and gold. Mercapto modified bipyridine ruthenium based catalyst Ru1, was synthesized by chemisorption between AuNPs and sulfhydryl. The catalyst was supported on the surface of AuNPs/BiVO_4 electrode. The photocatalytic water oxidation of Ru1/AuNPs/BiVO_4 anode was studied. Under 100 mW/cm~2 illumination, the current density of the photoanode was 4 times higher than that of BiVO_4 and 1.5 times higher than that of AuNPs/BiVO_4 under 0.62 V vs Ag/AgCl bias voltage Ru1 / AuNPs / BiVO4. And there is no obvious current drop in the test time, and a relatively stable constant current is obtained.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;O646.5
【相似文献】
相关期刊论文 前10条
1 潘孟美;;染料敏化太阳能电池掺杂光阳极的研究进展[J];海南师范大学学报(自然科学版);2018年01期
2 袁耀;王爱军;覃方丽;张鸿羽;;TiO_2反蛋白石结构光阳极结构改性及光电性能研究[J];广州化工;2017年02期
3 薛玫;张改清;高淑娟;崔晓瑞;;染料敏化太阳能电池光阳极的研究进展[J];广州化工;2014年02期
4 文世杰;高清华;孙璧Z，
本文编号：2254045
本文链接：https://www.wllwen.com/kejilunwen/huaxue/2254045.html
教材专著
