简单添加氧化石墨烯促进纳米金催化邻硝基苯胺还原

发布时间：2018-04-29 22:37

本文选题：氧化石墨烯 + 金纳米棒　；参考：《湖南工业大学》2015年硕士论文

【摘要】：贵金属纳米材料因其具有优异的催化性能,有着广泛的应用前景。贵金属纳米材料所具备的的催化性能与颗粒的尺寸、形貌密不可分,因此贵金属纳米材料的可控制备至关重要。本论文以苯三酚(1,2,4-苯三酚、1,2,3-苯三酚)为新型还原剂,发展了新型的金纳米棒制备方法。通过简单添加氧化石墨烯(GO)促进金纳米材料催化邻硝基苯胺的还原。主要内容如下:(1)分别以1,2,4-苯三酚、1,2,3-苯三酚为还原剂,采用种子生长法制备金纳米棒,同时研究了不同的因素如硝酸银的浓度、还原剂的浓度以及种子用量等对金纳米棒合成的影响。结果表明,以1,2,4-苯三酚为还原剂,合成的GNRs的LSPR吸收峰在698~913 nm范围可调,最大长径比为4.9;以1,2,3-苯三酚为还原剂,合成的GNRs的LSPR吸收峰在630~880 nm范围可调,最大长径比为4.7。这样的结果表明了本方法可制备不同长径比、形貌均一的GNRs,与AA为还原剂制备GNRs相比,以新型还原剂制备的GNRs具有LSPR吸收峰可调范围更宽的优点。(2)采用改进的Hummers法制备了GO,利用扫描电镜(SEM)、紫外可见光谱(UV-Vis)、红外光谱(FTIR)、Zeta电势等表征手段对制备的GO进行了表征。结果表明,所制备的GO表面含有丰富的含氧官能团,在中性水溶液中带负电,Zeta电势为-36.4 m V,在水溶液中能够稳定分散。(3)邻硝基苯胺催化还原。采用GNRs、Au-citrate、Au-CTAC为催化剂催化硼氢化钠还原邻硝基苯胺。通过简单添加GO可以提高纳米金的催化性能,并且催化反应的反应速率随着GO浓度的升高而增大。相同条件下,催化邻硝基苯胺还原的实验中,Au-citrate的催化活性比Au-CTAC高。
[Abstract]:Noble metal nanomaterials have a wide range of applications due to their excellent catalytic properties. The catalytic properties of noble metal nanomaterials are closely related to the size and morphology of particles, so the controllable preparation of noble metal nanomaterials is very important. In this paper, a new preparation method of gold nanorods has been developed, in which a new type of reductant was used to prepare gold nanorods. The reduction of o-nitroaniline catalyzed by gold nanomaterials was promoted by simply adding graphene oxide (GOO). The main contents are as follows: (1) the gold nanorods were prepared by seed growth method, using 1 (2) (4) -pyrogallol (1) 2 (2) -pyrogallol as reducing agent, and the concentration of different factors, such as silver nitrate, was studied. The effects of the concentration of reductant and the amount of seed on the synthesis of gold nanorods. The results show that the LSPR absorption peak of the synthesized GNRs is adjustable in the range of 698nm and the maximum aspect ratio is 4.9, and the LSPR absorption peak of the synthesized GNRs can be adjusted in the range of 630880nm and the maximum aspect ratio is 4.7by using 1kW 2N 4- pyrogallol as the reductant, and the maximum aspect ratio of the synthesized GNRs is 4. 7 nm, and the LSPR absorption peak of the synthesized GNRs can be adjusted in the range of 630880 nm with the maximum aspect to diameter ratio of 4. 7 nm. The results show that GNRs with different aspect ratio and uniform morphology can be prepared by this method, compared with AA as reducing agent. The GNRs prepared by a new reductant has the advantage of wider range of LSPR absorption peak. GOA was prepared by modified Hummers method. Go was characterized by scanning electron microscope (SEM), UV visible spectrum (UV) and infrared spectrum (FTIR) Zeta potential. The results showed that the surface of go was rich in oxygen-containing functional groups. The Zeta potential with negative charge in neutral aqueous solution was -36.4 MV, and the catalytic reduction of o-nitrophenylamine was stable and dispersed in aqueous solution. The reduction of o-nitroaniline by sodium borohydride was studied using GNRsN Au-citraten Au-CTAC as catalyst. The catalytic performance of gold nanoparticles can be improved by adding go simply, and the reaction rate of catalytic reaction increases with the increase of go concentration. Under the same conditions, the catalytic activity of Au-citrate was higher than that of Au-CTAC.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O621.251;TB383.1

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