Institute for Clean Energy & Advanced Materials, Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Faculty of Materials & Energy, Southwest University, Chongqing, China.
Institute for Clean Energy & Advanced Materials, Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energies, Faculty of Materials & Energy, Southwest University, Chongqing, China.
J Colloid Interface Sci. 2017 Nov 1;505:32-37. doi: 10.1016/j.jcis.2017.05.069. Epub 2017 May 23.
Heteroatom-doped graphene have encouraged intensive research as promising metal-free oxygen reduction reaction (ORR) electrocatalysts but the correlation between the precursor material and final ORR activity remains unclear. In this work a serial of nitrogen/sulfur (N/S)-doped graphene catalysts were synthesized by modifying graphene oxide (GO) with cysteine as a N/S source and sequential thermal annealing. It is disclosed that the cysteine-GO reaction time shows a significant influence on the ORR activity of N/S-doped graphene. A unique process of oxidation-induced in situ disulfide formation is further found to be involved in the synthesis of optimal N/S-doped graphene, which displays ORR activity superior to commercial Pt/C in alkaline media. This work suggests that the heteroatom source itself and careful optimization of reaction conditions are critical to obtain high performance doped-graphene electrocatalyst.
杂原子掺杂石墨烯作为有前途的无金属氧还原反应（ORR）电催化剂受到了广泛的研究，但前体材料与最终 ORR 活性之间的关系仍不清楚。在这项工作中，通过使用半胱氨酸作为 N/S 源和顺序热退火来修饰氧化石墨烯（GO），合成了一系列氮/硫（N/S）掺杂石墨烯催化剂。研究表明，半胱氨酸-GO 的反应时间对 N/S 掺杂石墨烯的 ORR 活性有显著影响。进一步发现，在最优 N/S 掺杂石墨烯的合成过程中涉及到氧化诱导的原位二硫键形成的独特过程，其在碱性介质中的 ORR 活性优于商业 Pt/C。这项工作表明，杂原子源本身和反应条件的仔细优化对于获得高性能掺杂石墨烯电催化剂至关重要。
