Davidraj Jefrin M, Sathish C I, Selvarajan Premkumar, Fawaz Mohammed, Perumalsamy Vibin, Yu Xiaojiang, Breese Mark B H, Yi Jiabao, Vinu Ajayan
Global Innovative Centre for Advanced Nanomaterials (GICAN), School of Engineering, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Vellore, India.
Nanoscale. 2024 Sep 12;16(35):16439-16450. doi: 10.1039/d4nr02425g.
The electrocatalytic activity of carbon materials is highly dependent on the controlled modulation of their composition and porosity. Herein, mesoporous N-doped carbon with different amounts of nitrogen was synthesized through a unique strategy of using a high nitrogen containing CN precursor, 3-amino 1,2,4 triazine (3-ATZ) which is generally used for the preparation of carbon nitrides, integrated with the combination of a templating method and high temperature treatment. The nitrogen content and the graphitisation of the prepared materials were finely tuned with the simple adjustment of the carbonisation temperature (800-1100 °C). The optimised sample as an electrocatalyst for oxygen reduction reaction (ORR) exhibited an onset potential of 0.87 V RHE with a current density of 5.1 mA cm and a high kinetic current density () of 33.1 mA cm at 0.55 V RHE. The characterisation results of the prepared materials indicated that pyridinic and graphitic nitrogen in the carbon framework promoted ORR activity with improved four-electron selectivity and excellent methanol tolerance and stability. DFT calculations demonstrated that the structural and planar defects in the N-doped carbon regulated the surface electronic properties of the electrocatalyst, leading to a reduction in the energy barrier for the ORR activity. This strategy has the potential to unlock a platform for designing a series of catalysts for electrochemical applications.
碳材料的电催化活性高度依赖于其组成和孔隙率的可控调节。在此,通过一种独特的策略合成了具有不同氮含量的介孔氮掺杂碳,该策略是使用高含氮的CN前驱体3-氨基-1,2,4-三嗪(3-ATZ,通常用于制备碳氮化物),并结合模板法和高温处理。通过简单调整碳化温度(800 - 1100°C),可以精细调节所制备材料的氮含量和石墨化程度。作为氧还原反应(ORR)电催化剂的优化样品在0.55V(相对于可逆氢电极,RHE)时的起始电位为0.87V(相对于RHE),电流密度为5.1mA/cm²,在0.55V(相对于RHE)时具有33.1mA/cm²的高动力学电流密度()。所制备材料的表征结果表明,碳骨架中的吡啶型氮和石墨型氮促进了ORR活性,具有提高的四电子选择性以及优异的甲醇耐受性和稳定性。密度泛函理论(DFT)计算表明,氮掺杂碳中的结构和平面缺陷调节了电催化剂的表面电子性质,导致ORR活性的能垒降低。该策略有潜力为设计一系列用于电化学应用的催化剂开辟一个平台。