聚多巴胺介导的异原子掺杂的石墨烯/碳纳米管自支撑膜电极的制备及电催化析氢研究

The commercial application of electrocatalytic hydrogen evolution reaction (HER) is greatly hampered by the use of precious Pt catalysts. The development of novel HER electrocatalysts is essential for the replacement of Pt. The heteroatom-doped carbon materials have aroused tremendous interests because of their low cost, competitive activity and significantly enhanced stability. On the basis of our previous work, this study intends to use polydopamine as a mediator to fabricate N-doped and N, S dual-doped graphene/carbon nanotube free-standing film. On one hand, by using polydopamine and its thiol addition, we can extend the polydopamine-mediated doping method to the macro-size film materials and realize the simple and effective doping and as well as the quantitative doping of sulfur. On the other hand, polydopamine can deposit onto the materials’ surface and form the uniform and continuous thin film, this feature makes polydopamine as the glue to integrate the different components of film, and thus improve the mechanical properties of film. We will investigate the promotion of N-doping and N, S-dual doping on HER electrocatalytic activity of film electrode and discuss the relationship between the amount of sulfur doping and HER catalytic activity, and then evaluate the role of polydopamine in the improvement of long-term stability of film electrode. This study will further confirm the universality and superiority of polydopamine in constructing the N, S dual-doping and provide a new route for the development of composite electrocatalysts.

贵金属Pt催化剂的使用限制了电催化析氢反应的大规模商业化应用，开发新型的电催化剂取代贵金属势在必行。杂原子掺杂的碳纳米材料因成本低廉、催化性能高效且稳定收到广泛的研究。在前期工作的基础上，本课题拟用聚多巴胺为媒介，合成氮掺杂和氮硫双掺杂的石墨烯/碳纳米管自支撑膜。一方面，通过聚多巴胺及其硫加成反应，将聚多巴胺介导的掺杂方法扩展到宏观尺寸的膜材料，达到简单高效掺杂的同时，实现定量的硫掺杂；另一方面，聚多巴胺可在材料表面沉积形成均匀连续的薄层，这一特性使聚多巴胺像胶水一样将膜内部组分石墨烯和碳纳米管粘合，改善膜的力学性能。我们将分别研究氮掺杂和氮硫双掺杂对析氢反应电催化活性的促进作用，考察硫掺杂量与催化活性之间的关系，评价聚多巴胺组分在改善膜电极稳定性中的作用。本课题将进一步证实聚多巴胺介导的氮硫双掺杂的普适性和优越性，为开发复合材料电催化剂提供新路线。

碳纳米材料具有成本低廉、组分结构可调和性能稳定等优点，在取代贵金属基电催化剂上显示出巨大潜力。杂原子掺杂可有效提高碳材料的电催化性能。本项目利用聚多巴胺丰富的物理化学性质，围绕基于聚多巴胺的掺杂碳材料进行了系统的研究，通过宏观优化掺杂碳材料的组分和结构，实现了掺杂碳材料的电子结构、自旋密度差异和孔结构的微观调控，深入探讨了电催化剂的构效关系规律，本项目证实了基于聚多巴胺的掺杂碳材料在合成方法和电催化性能上的优越性，为开发聚多巴胺复合材料在能源相关领域的应用提供新路线。（1）利用聚多巴胺成功合成具有HER和OER高效双功能的氮硫双掺杂碳纳米管，系统研究了氮硫双掺杂的协同作用，提出氮硫双掺杂引起的自旋密度差异是高效双功能活性的起源。（2）构建了聚多巴胺介导的氮硫、氮磷和氮硼双掺杂平台，评价助掺杂剂（硼、磷和硫）对氮掺杂碳材料在HER活性上的促进作用，提出电子结构是电催化性能的决定性因素，只有保障良性电子结构的前提下，改善材料的比表面积才可进一步提高催化剂的表观活性。（3）利用聚多巴胺独特的粘附性，调控基底或模板材料合成一系列具有不同形貌结构的掺杂碳材料，包括碳纳米片、碳纳米管和介孔碳。（4）发现PDA衍生的掺杂碳材料具有电催化活性的多功能性，如在HER、OER和ORR上都表现出优异的性能，为开发多功能电催化剂提供指导意义。基于以上研究，项目负责人在Advanced Energy Materials、ACS Nano、Journal of Materials Chemistry A和ChemNanoMat等期刊发表论文14篇，两篇入选ESI高被引论文。