【作者】 曾炜；

【导师】 孙净雪；

【作者基本信息】 哈尔滨工业大学 ， 物理化学， 2017， 硕士

【摘要】 21世纪以来,化石能源的枯竭和环境污染日趋严重,严重阻碍了人类社会的高速发展。如何开发清洁的可再生能源是当今社会的重要的研究方向之一。氢能作为一种高效,绿色无污染的可再生能源,是一种具有极大发展前景的二次能源。相比于传统的制氢手段,光催化制氢作为一种新兴的制氢方法,因其通过转化来源广泛的太阳能而备受关注。而光催化技术最为关键的便是光催化剂的合成。在众多光催化剂中,石墨相氮化碳作为新型的无机非金属光催化剂,因其具有良好的稳定性,合适的带隙宽度,而受到人们的广泛关注,一直是领域内的研究热点。本论文通过熔盐热合成七嗪环结构的石墨相氮化碳,经过一系列的实验探索,制备出了性能优异的七嗪环结构石墨相氮化碳。结合表征测试和性能测试对合成的七嗪环结构的石墨相氮化碳材料的结构、性能及构效关系进行研究。通过调节原料和盐的比例、反应温度及时间等一系列实验参数,制备了纳米棒结构石墨相氮化碳,并深刻研究了各项实验参数对其生长过程和形貌的影响,结合制氢测试,确定了熔盐法合成七嗪环结构的石墨相氮化碳的最佳工艺参数。再利用草酸铵改性热聚法石墨相氮化碳光催化剂,研究发现草酸铵的加入能够参与三聚氰胺的缩聚过程,从而在石墨相氮化碳结构中插入酰胺基团,改变了石墨相氮化碳的微观形貌、光学性质和制氢性能,同时,在反应的过程中草酸铵分解为NH3和CO2,其原本占据的位置变为了孔洞,起到了造孔剂的作用。在原本光滑的片层结构表面引入了孔洞,增大了样品的比表面积,增加了反应的活性位点,而酰胺的引入有利于电荷的传输,提高了光生载流子的分离效率,显著提升该材料的光催化制氢性能。在前两者合成的基础上,利用热聚法合成的石墨相氮化碳光催化剂作为基底,熔盐法合成的石墨相氮化碳作为主体,利用熔盐的尺寸效应在基底上生长,使棒状结构的石墨相氮化碳包裹在热聚法合成的石墨相氮化碳上,从而构筑了具有纳米尺寸接触界面的同质结构。这样的同质结构能够有效地分离光生电子和空穴,从而提高该材料的光催化产氢性能。更多还原

【Abstract】 Since the 21 st century,fossil energy depletion and environmental pollution has became a serious challenge,which is a serious harm to the rapid development of human society.How to develop a clean renewable energy is one of the important research in today’s society.Hydrogen,as a highly efficient,green pollution-free renewable energy,is a great potential for the development of secondary energy.Compared with the traditional hydrogen production method,a new method,photocatalytic hydrogen production gains widespread concern,because it can use a wide range of solar energy.The most critical of photocatalytic technology is the synthesis of photocatalyst.Among the many photocatalysts,graphite carbon nitride as a new type of inorganic nonmetallic photocatalyst has been widely studied in the field because of its good stability and suitable band gap width.In this paper,the graphite carbon nitride was prepared by the molten salt method.After several times experiement,we synthesized the graphite carbon nitride successfully.The structure,properties and the relationship of the graphite carbon nitride were studied by characterization and measurement.Graphite carbon nitride with nanorod structure were synthesized by adjusting the ratio of raw materials and salt,reaction temperature and time.The effects of various experimental parameters on the growth process and morphology were studied.The optimum process parameters of the graphite carbon nitride were synthesized by the molten salt method.The addition of ammonium oxalate can be involved in the polycondensation process of melamine.On the on hand,inserting the amide group in the graphite carbon nitride structure and change the microstructure appearance,optical properties and hydrogen production performance.On the other hand,in the process of reaction of ammonium oxalate decomposition of NH3 and CO2,the original occupied position into a hole,played a role in pore-forming agent.In conclusion,the introduction of pores on the surface increases the specific surface area of the sample and increases the active sites of the reaction.And the introduction of the amide groups is beneficial to the transport of the charge and impr oves the separation efficiency of the photogenerated carriers.The photocatalytic hydrogen production of the material was improved.The graphite phase carbon nitride photocatalyst synthesized by thermal polymerization method was used as the substrate,and the graphite phase carbonitride synthesized by the molten salt method was used as the subjectee,and the size of the molten salt was used to grow on the substrate to encapsulate the graphite The homogeneous structure with nano-sized contact interface was constructed on the graphite phase carbonitride synthesized by thermal polymerization.This homojunction can effectively separate the photo-generated electrons and holes,thereby improving the photocatalytic hydrogen production of the material.更多还原