Interconnected Hollow Cobalt Phosphide Grown on Carbon Nanotubes for Hydrogen Evolution Reaction Alaaldin Adam Munzir H. Suliman Mohammad N. Siddiqui Zain H. Yamani Belabbes Merzougui Mohammad Qamar 10.1021/acsami.8b03427.s001 https://acs.figshare.com/articles/journal_contribution/Interconnected_Hollow_Cobalt_Phosphide_Grown_on_Carbon_Nanotubes_for_Hydrogen_Evolution_Reaction/7010279 Transition-metal phosphides are deemed as potential alternative to platinum for large-scale and sustainable electrocatalytic hydrogen production from water. In this study, facile preparation of interconnected hollow cobalt monophosphide (CoP) supported on carbon nanotubes is demonstrated and evaluated as a low-cost electrocatalyst for hydrogen evolution reaction. Hexamethylenetetramine is used as a structure-directing agent to guide the formation of interconnected cobalt oxide, which further grows into interconnected hollow CoP. Interconnected and hollow microstructural artifacts impart benign attributes, such as enhanced specific and electrochemically active surface area, low intrinsic charge transfer resistance, high interfacial charge transfer kinetics, and improved mass transport, to the electrocatalyst. As a result, the as-prepared electrode exhibits remarkable electrocatalytic performance, low onset (18 mV) and overpotential (η<sub>10</sub> = 73 mV); small Tafel slope (54.6 mV dec<sup>–1</sup>); and high turnover frequency (0.58 s<sup>–1</sup> at η = 73 mV). In addition, the electrode shows excellent electrochemical stability. 2018-08-13 00:00:00 surface area electrochemical stability Hydrogen Evolution Reaction Transition-metal phosphides mass transport cobalt monophosphide hydrogen evolution reaction carbon nanotubes electrocatalyst structure-directing agent charge transfer kinetics Carbon Nanotubes 73 mV electrocatalytic performance electrocatalytic hydrogen production Interconnected Hollow Cobalt Phosphide Grown microstructural artifacts CoP cobalt oxide as-prepared electrode exhibits charge transfer resistance