【作者】 张鹏；

【导师】 孙念祖（Nian-Tzu Suen）； 吴战宇；

【作者基本信息】 扬州大学 ， 工程硕士（专业学位）， 2020， 硕士

【摘要】 现如今,随着工业水平的不断提高造成了化石能源的大规模利用,进而造成了环境污染、能源枯竭等一系列问题,因此,很多科学家致力于研究电催化水分解电极材料以制取燃烧热值高、清洁无污染、便于储存和运输氢能来代替传统的化石能源。但由于电催化水分解阳极材料产氧过程中所需电位过大、稳定性较差等问题已逐渐成为该领域研究的瓶颈。因此我们通过简单的直接元素固相合成法及氩弧焊技术合成了一系列过渡金属磷化物并通过三个部分的研究分别对碱性条件下电催化水分解阳极材料的选择、新型高效析氧反应催化材料的设计及材料析氧反应催化效能的提升进行了系统性的探索。第一部分,通过对该领域前人研究的成果进行整理,同时结合理论计算的对材料电子结构的分析,发现镍基材料结构中存在大量的Ni-Ni键接且费米能级以下存在Ni-Ni反键,则该化合物具有优异的析氧反应催化效能及稳定性。因此,我们对富含Ni-Ni键接的不同结构磷化镍(Ni5P2、Ni3P和Ni5P4)的析氧反应(OER)进行了研究。电化学测试结果表明,费米能级以下存在Ni-Ni反键的Ni5P2和Ni3P在保证良好的析氧反应催化活性的同时还能保持极高的稳定的稳定性,且仅仅需要340 mV的过电位就可达到电流密度100 mA·cm-2,并稳定反应了 12 h。第二部分,我们设计并合成了新型的化合物,并对其析氧反应催化性能做了系统的研究,我们用部分的Si取代Ni5P2结构中部分的P,得到了 Ni8P3结构的新型化合物Ni8Si1.5P1.5、Ni8Si2P并与其结构相似的Ni31Si12材料一起进行探究,Ni8Si1.5P1.5在高电流密度下展现了卓越的析氧反应催化活性及稳定性,仅需330 mV就可达到电流密度100 mA·cm-2并稳定反应了 12 h甚至更久。第三部分,为了提高材料性能,我们用部分的Ge分别取代Ni8P3结构中部分的P,得到了 Ni8GexP(1-x)新化合物,拉长了 Ni8P3结构中的Ni-Ni键接,极大的提高了材料性能,同时新化合物中Fe的掺入大大降低析氧反应电位的同时也提高了该化合物高电流密度下的稳定性。研究过程中,我们均对材料进行了大电流密度的测试,Ni7FeGeP2展现了非常优异的效能和稳定性。相信该研究可以帮助设计低成本、高催化活性和高稳定性的析氧反应催化剂材料的大规模生产作出贡献。更多还原

【Abstract】 Nowadays,with the continuous improvement of the industrial level,the large-scale utilization of fossil energy has resulted in a series of problems,such as environmental pollution,energy depletion,etc.Therefore,many scientists are committed to the study of electrocatalytic water decomposition electrode materials to produce high combustion heat value,clean and pollution-free,easy to store and transport hydrogen energy to replace the traditional fossil energy.However,due to the large potential and poor stability in the process of electrocatalytic water decomposition anode material oxygen production,it has gradually become a bottleneck in this field.Therefore,we have synthesized a series of transition metal phosphides by simple solid-phase synthesis of direct elements and argon arc welding technology,and systematically explored the selection of anode materials for electrocatalytic water decomposition under alkaline conditions,the design of new efficient catalytic materials for oxygen evolution reaction and the improvement of catalytic efficiency of oxygen evolution reactionIn the first part,through sorting out the previous research results in this field,and combining with the theoretical calculation of the electronic structure of materials,it is found that there are a lot of Ni-Ni bonds in the structure of nickel based materials and there are Ni-Ni anti bonds below the Fermi level,so the compound has excellent catalytic efficiency and stability for oxygen evolution reaction.Therefore,we studied the oxygen evolution reaction(OER)of nickel phosphide(Ni5P2、Ni3P and Ni5P4)with different structures rich in Ni-Ni bonding.The results of electrochemical tests show that Ni5P2 and Ni3P with Ni-Ni anti bond below Fermi level can maintain high stability while maintaining good catalytic activity for oxygen evolution reaction,and the current density can reach 100 mA·cm-2 with only 340 mV overpotential,and the reaction has been stable for 12 h.In the second part,we designed and synthesized new compounds,and systematically studied their catalytic performance of oxygen evolution reaction.We replaced part of P in Ni5P2 structure with part of Si,and obtained Ni8Si1.5P1.5、Ni8Si2P and Ni31Si12 materials with similar structure.Ni8Si1.5P1.5 showed excellent oxygen evolution reaction at high current density,the current density of 100 mA·cm-2 can be reached at 330 mv and the reaction is stable for 12 hours or even longer.In the third part,in order to improve the properties of the materials,we use part of Ge to replace part of P in Ni8P3 structure,and obtain a new Ni8GexP(1-x)compound,which elongates the Ni-Ni bond in Ni8P3 structure,greatly improving the properties of the materials.At the same time,the incorporation of Fe in the new compound greatly reduces the oxygen evolution reaction potential and improves the stability of the compound at high current density.In the research process,we have tested the materials with high current density,and Ni7FeGeP2 has shown very excellent performance and stability.It is believed that the research can contribute to the large-scale production of catalyst materials for oxygen evolution reaction with low cost,high catalytic activity and high stability.更多还原