Carbon nanotubes decorated with CoP nanocrystals: A highly active non-noble-metal nanohybrid electrocatalyst for hydrogen evolution

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 40mV, a Tafel slope of 54mVdec -1, an exchange current density of 0.13mAcm-2, and a Faradaic efficiency of nearly 100%. This catalyst maintains its catalytic activity for at least 18hours and only requires overpotentials of 70 and 122mV to attain current densities of 2 and 10mAcm-2, respectively. A nanohybrid that consists of carbon nanotubes decorated with CoP nanocrystals (CoP/CNT) was prepared by the low-temperature phosphidation of a Co 3O4/CNT precursor. As a novel non-noble-metal hydrogen-evolution electrocatalyst that operates in acidic media, this nanohybrid exhibits an onset overpotential of only 40mV and maintained its catalytic activity for at least 18hours. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.