基于氮掺杂三维多级孔石墨烯的电化学传感平台

The design and exploration of novel graphene based electrode material play an important role in high performance electrochemical devices. This project proposes to prepare a nitrogen-doped, three dimensional hierarchical graphene (N-3DHPG) as electrochemical sensing platform material, which is designed to overcome several shortages of two dimensional planar graphene in electrochemical sensing (such as the stacking of graphene sheet, the relative low electrocatalysis, the low efficiency of mass transport) by combing the synergistic interaction of three-dimensional macroporous-, two dimensional mesoporous-, and nitrogen-doped-structures, and consequently improves the performance of corresponding electrochemical sensors. In this project, N-3DHPG will be prepared by self-assembly technique combined with chemical etching process and nitrogen doping method. The effects of preparation parameters on the structure and component of the N-3DHPG will be investigated in order to achieve the controlled preparation of the N-3DHPG. The properties, especially the electrochemical activity of N-3DHPG will be characterized by modern techniques, and its dependence on the structure and component of N-3DHPG will be studied in detail. Furthermore, composites of N-3DHPG with some functional material such as gold nanoparticles, redox-active enzyme and protein will be prepared, and the effects of N-3DHPG on the electrochemical activity of these functional materials will be investigated to reveal the interaction between them. Finally, several high performance electrochemical sensors for different target molecules will be constructed, and the mechanism of N-3DHPG in these sensors will be discussed. The results of this project will provide a new approach for tailing the performance of graphene material, and provide new materials or methods for the highly-sensitive detection of some important bio-chemical molecules.

新颖石墨烯电极材料的设计、开发对于发展高性能的电化学装置具有重要的科学意义。本课题拟制备氮掺杂的三维多级孔石墨烯（N-3DHPG）用作电化学传感平台材料，通过三维大孔、二维介孔、氮掺杂三种结构的协同作用克服二维石墨烯片严重堆积、催化活性较低、传质阻力大的不足，提升电化学传感器性能。结合自组装、化学刻蚀及氮掺杂方法制备N-3DHPG，考察制备条件对其结构、成分的影响规律，实现N-3DHPG可控制备，揭示其结构成分特性与其比表面积、电催化性能、传质性能等理化性质之间的内在联系及调控规律；制备N-3DHPG与金或铂纳米粒子、几种氧化还原酶或蛋白质等传感功能材料的复合物，揭示N-3DHPG对功能材料活性的影响机制；基于N-3DHPG或其复合物构建针对不同分析物的传感器，阐明N-3DHPG在传感界面的作用机制。项目实施将为石墨烯材料的性能调控提供新途径，为重要生化分子的高灵敏分析提供新材料及新方法。

项目资助期间我们围绕研究目标和研究内容开展了下列工作：（1）利用水热组装或者原位生长法制备三维大孔石墨烯及其复合材料，构建电化学传感器，揭示了大孔结构对提升传感性能的作用机制。（2）探索了三种制备三维多级孔石墨烯的方案，结果表明水热组装-H2O2腐蚀法最为简便，介孔尺寸小；碳热刻蚀法纳米孔尺寸可控性高；微波法造孔重现性差。（3）基于三维多级孔石墨烯构建了电化学传感器，实现了对多巴胺及苯二酚异构体的高灵敏电化学检测。揭示了三维多级孔中的介孔结构的关键作用：提升传质效率，提高催化性能，但引入介孔量过多则缺陷过多，性能降低。（4）对三维大孔石墨烯及三维多级孔石墨烯掺氮，考察了掺氮方法及多级孔结构对掺氮效果的影响。结果表明多级孔结构可以提供更多掺氮位点，提高掺氮量；不同方法对掺氮提升效果存在差异：水合肼水热处理掺氮量在2%左右，两种材料掺氮量相差15%以上；等离子掺杂法可将多级孔石墨烯掺氮量由不足1%增至5%左右，对两种材料掺氮量相差3倍以上。（5）基于氮掺杂三维多级孔石墨烯，构建了多巴胺传感器；进一步负载葡萄糖氧化酶考察了该修饰电极上的电化学行为。通过一系列对比实验表明：多级孔结构和氮掺杂在适当条件下可以实现协同作用，增加多级孔结构可提高氮掺杂量，提升催化活性及传感器性能，而超过一定阈值后性能下降。本项目以通讯作者或第一作者在SCI收录的刊物上发表相关科研论文6篇，获得2020年江西省科学技术奖自然科学奖二等奖（排名第三），吉林省自科奖三等奖（排名第二），培养硕士毕业研究生2人，参加学术会议4次，基本完成计划目标。