Highly branched cobalt phosphide nanostructures for hydrogen-evolution electrocatalysis
CoP nanostructures that exposed predominantly (111) crystal facets were synthesized and evaluated for performance as electrocatalysts for the hydrogen-evolution reaction (HER). The branched CoP nanostructures were synthesized by reacting cobalt(II) acetylacetonate with trioctylphosphine in the presence of trioctylphosphine oxide. Electrodes comprised of the branched CoP nanostructures deposited at a loading density of ~1 mg cm^(−2) on Ti electrodes required an overpotential of −117 mV to produce a current density of −20 mA cm^(−2) in 0.50 M H_2SO_4. Hence the branched CoP nanostructures belong to the growing family of highly active non-noble-metal HER electrocatalysts. Comparisons with related CoP systems have provided insights into the impact that shape-controlled nanoparticles and nanoparticle–electrode interactions have on the activity and stability of nanostructured HER electrocatalysts.
© 2015 The Royal Society of Chemistry. Received 3rd December 2014; Accepted 15th January 2015; First published online 16 Jan 2015. The work at PSU was supported by the National Science Foundation (NSF) Center for Chemical Innovation on Solar Fuels (CHE-1305124) and at Caltech by the Joint Center for Artificial Photosynthesis, a DOE Energy Innovation Hub, supported through the Office of Science of the U.S. Department of Energy under Award Number DE-SC0004993, as well as the Gordon and Betty Moore Foundation. TEM was performed in the Penn State Microscopy and Cytometry Facility (University Park, PA) and HRTEM, EDS, SEM, and BET data were acquired at the Materials Characterization Laboratory of the Penn State Materials Research Institute. C.W.R. thanks the NSF for a graduate research fellowship.
Published - c4ta06642a.pdf
Supplemental Material - c4ta06642a1_si.pdf