【作者】 李晓；

【导师】 李旦振；

【作者基本信息】 福州大学 ， 材料物理与化学， 2016， 硕士

【摘要】 自从Fujishima和Honda发现并报道了紫外光照射Ti02半导体电极可以将水分解产生氢气的四十多年间,光催化领域的研究进展引人注目。人们渐渐意识到光能与其他形态的能量相互协同有助于提高能量的利用率。开展具有良好的光热协同催化性能的研究,它对于解决能源枯竭和利用率低下的难题具有很高的研究价值和重要的科学意义。InVO4作为一种对可见光响应的半导体,与传统的光催化半导体材料TiO2进行复合,不但将其吸收光谱范围拓宽了 130 nm左右,大幅提高了太阳光能利用率,并在空间上实现了光生载流子的有效分离,降低了光生电子和空穴的复合几率。更为重要的是,我们发现InVO4/TiO2光催化剂具有良好的光热协同催化性能,其在180 ℃的较低温度下即可将气体有机污染物苯完全氧化分解,其催化效果比单独光催化和热催化效果之和要高约12.5%。为了进一步优化其催化性能,将复合光催化剂与极少量的贵金属Pt进行复合,在80 ℃的低温下就可将苯完全氧化,大幅降低了其完全氧化降解苯所需的温度。Pt的负载有效增强了光热催化耦合效应,其催化效果比单独光催化与热催化之和高约90%。另外,我们还就Pt-InVO4/TiO2的光解水制氢性能进行了较深入的探究,经过一系列优化之后,将其产氢量提高至1263 μmol/g,紫外光下量子效率达到6.90%,有效地拓展了其在光催化应用领域的潜力。本论文的创新点如下:(1)首次发现了 InVO4/TiO2在不负载贵金属的情况下具有光热耦合催化效应,在180 ℃下即可完全降解有机污染物苯,远远低于工业热催化所需的温度;(2)利用少量Pt在InVO4/TiO2上的负载,将复合光催化剂完全氧化降解苯的温度降低至80 ℃,且其光热耦合效果提高了 7.2倍;(3)创新性的拓展了 Pt-InVO4/TiO2在光解水制氢方面的性能,并对实验条件进行了相关的优化,使其4小时内的产氢量高达1263 μmol/g。更多还原

【Abstract】 Since Fujishima and Honda reported their discovery on Nature that water can be decomposed to produce H2 with the using of TiO2 semiconductor electrode and metal electrode irradiated by light,photocatalytic technology has attracted lots of attention during forty years.It was realized that light energy can be combined with other energy to improve the utilization efficiency of the catalysts.The study on the photothermal synergetic effect will be able to solve the problems of the modern global energy depletion and the low energy efficiency.As a kind of semiconductor which can be responded to visible light,InVO4 helps the traditional photocatalytic material TiO2 broadening the absorption spectrum about 130 nm,raising the utilization rate of solar energy,realizing the efficient separation of photo-generated carriers in space,and reducing their recombination.Most importantly,it was found that the composite photocatalyst InVO4/TiO2 has a photothermocatalytic effect,which can degrade benzene at the low temperature of 180 ℃,and the synergetic efficiency is 12.5%higher than the sum of single photocatalysis and thermocatalysis.In order to further optimize the photocatalytic performance,InVO4/TiO2 was loaded with the noble metal Pt.The new composite Pt-InVO4/TiO2 greatly lowered the temperature to 80 ℃ at which benzene could be completely degraded,and at the same time,it strengthened the photothermocatalytic synergetic effect of the catalytic system,with the efficiency of 90%higher than the sum of single photocatalysis and thermocatalysis.In addition,the ability of photocatalytic water-splitting over Pt-InVO4/TiO2 was studied to dig out its potential in photocatalytic application area.After a series of experiments,the reaction conductions were optimized and the yield of hydrogen could be as high as 1263 μmol/g.The innovative points of this paper are as below:(1)The photothermocatalytic effect of InVO4/TiO2 without noble metal doping was discovered for the first time.Benzene could be totally degraded at the temperature of 180 ℃,and it is much lower than the one in industrial thermal catalytic reactions.(2)The temperature at which benzene can be totally degraded was greatly lowered to 80 ℃ after the microscale doping of Pt onto InVO4/TiO2.The synergetic efficiency of Pt-InVO4/TiO2 is about 7.2 times of InVO4/TiO2.(3)The performance of the composite catalyst Pt-InVO4/TiO2 in photocatalytic water-splitting was studied for the first time.The reaction conditions were optimized,and the yield of hydrogen could as high as 1263 μmol/g in four hours.更多还原