溶剂热法制备磷掺杂碳纳米管作为氧气还原和氧气析出反应双功能电催化剂的研究

对氧气还原(ORR)和氧气析出(OER)反应都具有催化活性的双功能催化剂在金属-空气电池中起着关键作用.本文通过溶剂热反应,一步原位合成了磷掺杂碳纳米管(P-CNT).旋转环盘电极测试表明磷掺杂能够明显提高碳纳米管的催化活性,P-CNT在碱性电解质中对ORR和OER都具有优异的催化活性.P-CNT对ORR的催化还原为近4电子反应,可与商业催化剂Pt/C(20 wt%)相比;而其对OER的催化活性则高于Pt/C(20 wt%).此外,P-CNT的长期稳定性优于Pt/C(20 wt%).P-CNT对ORR和OER的高催化活性和稳定性主要归因于磷对碳的掺杂以及磷与碳间强的化学键合.

A solvothermal synthesis of phosphorus doped carbon nanotube as a bi-functional electrocatalyst for oxygen reduction and oxygen evolution reaction

Electrocatalysts for the oxygen reduction and oxygen evolution reactions play a critical role in the performance of metal-air batteries. In this study, a phosphorus doped carbon nanotube （P-CNT） is facilely synthesized via a one-step process and in-situ solvothermal method. The electrocatalytic activity for the oxygen reduction reaction （ORR） and oxygen evolution reaction（OER） of the catalyst was studied with the rotating ring-disk electrode （RRDE） technique. The doping of phosphorus can obviously improve the electrocatalytic activity of CNT towards both the ORR and OER. Four electron reduction pathway is dominant on P-CNT during the ORR process, which is comparable to the commercial Pt/C （20 wt%）. The electrocatalytic activity of P-CNT towards the OER is superior to that of Pt/C （20 wt%）. Moreover, the long-term stability of P-CNT outperforms that of Pt/C （20 wt%）. The high electrocatalytic activity and long-term stability of P-CNT are attributed to P-doping in CNT and the strong coupling between phosphorus and carbon.