Nie Yao, Xu Xiaoqin, Wang Xinyu, Liu Mingyang, Gao Ting, Liu Bin, Li Lixin, Meng Xin, Gu Peng, Zou Jinlong
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, China.
School of Environment and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150080, China.
Nanomaterials (Basel). 2023 Jun 1;13(11):1788. doi: 10.3390/nano13111788.
Alloy-based catalysts with high corrosion resistance and less self-aggregation are essential for oxygen reduction/evolution reactions (ORR/OER). Here, via an in situ growth strategy, NiCo alloy-inserted nitrogen-doped carbon nanotubes were assembled on a three-dimensional hollow nanosphere (NiCo@NCNTs/HN) using dicyandiamide. NiCo@NCNTs/HN exhibited better ORR activity (half-wave potential (E) of 0.87 V) and stability (E shift of only -13 mV after 5000 cycles) than commercial Pt/C. NiCo@NCNTs/HN displayed a lower OER overpotential (330 mV) than RuO (390 mV). The NiCo@NCNTs/HN-assembled zinc-air battery exhibited high specific-capacity (847.01 mA h g) and cycling-stability (291 h). Synergies between NiCo alloys and NCNTs facilitated the charge transfer to promote 4e ORR/OER kinetics. The carbon skeleton inhibited the corrosion of NiCo alloys from surface to subsurface, while inner cavities of CNTs confined particle growth and the aggregation of NiCo alloys to stabilize bifunctional activity. This provides a viable strategy for the design of alloy-based catalysts with confined grain-size and good structural/catalytic stabilities in oxygen electrocatalysis.
具有高耐腐蚀性和低自聚集性的合金基催化剂对于氧还原/析氧反应（ORR/OER）至关重要。在此，通过原位生长策略，使用双氰胺在三维空心纳米球上组装了插入NiCo合金的氮掺杂碳纳米管（NiCo@NCNTs/HN）。与商业Pt/C相比，NiCo@NCNTs/HN表现出更好的ORR活性（半波电位（E）为0.87 V）和稳定性（5000次循环后E仅偏移-13 mV）。NiCo@NCNTs/HN的OER过电位（330 mV）低于RuO（390 mV）。组装有NiCo@NCNTs/HN的锌空气电池表现出高比容量（847.01 mA h g）和循环稳定性（291 h）。NiCo合金与NCNTs之间的协同作用促进了电荷转移，以推动4e ORR/OER动力学。碳骨架抑制了NiCo合金从表面到次表面的腐蚀，而CNTs的内腔限制了颗粒生长和NiCo合金的聚集，从而稳定了双功能活性。这为设计在氧电催化中具有受限晶粒尺寸和良好结构/催化稳定性的合金基催化剂提供了一种可行的策略。
