Carbon Nanotubes Decorated with CoP Nanocrystals: A Highly Active Non-Noble-Metal Nanohybrid Electrocatalyst for Hydrogen Evolution

• Published in: Angewandte Chemie International Edition 2014-06, Vol.53 (26), p.6710-6714
• Main Authors: Liu, Qian, Tian, Jingqi, Cui, Wei, Jiang, Ping, Cheng, Ningyan, Asiri, Abdullah M., Sun, Xuping
• Format: Article
• Language: English
• Subjects: Carbon nanotubes; Catalysis; Catalysts; cobalt nanocrystals; Decoration; Electrocatalysts; electrolysis; Exchange; heterogeneous catalysis; hydrogen evolution reaction; Nanocrystals; Nanostructure; Nanotubes; Precursors
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201404161

The development of effective and inexpensive hydrogen evolution reaction (HER) electrocatalysts for future renewable energy systems is highly desired. The strongly acidic conditions in proton exchange membranes create a need for acid‐stable HER catalysts. A nanohybrid that consists of carbon nanotubes decorated with CoP nanocrystals (CoP/CNT) was prepared by the low‐temperature phosphidation of a Co3O4/CNT precursor. As a novel non‐noble‐metal HER catalyst operating in acidic electrolytes, the nanohybrid exhibits an onset overpotential of as low as 40 mV, a Tafel slope of 54 mV dec−1, an exchange current density of 0.13 mA cm−2, and a Faradaic efficiency of nearly 100 %. This catalyst maintains its catalytic activity for at least 18 hours and only requires overpotentials of 70 and 122 mV to attain current densities of 2 and 10 mA cm−2, respectively. A nanohybrid that consists of carbon nanotubes decorated with CoP nanocrystals (CoP/CNT) was prepared by the low‐temperature phosphidation of a Co3O4/CNT precursor. As a novel non‐noble‐metal hydrogen‐evolution electrocatalyst that operates in acidic media, this nanohybrid exhibits an onset overpotential of only 40 mV and maintained its catalytic activity for at least 18 hours.