%0 Journal Article %A Callejas, Juan F. %A McEnaney, Joshua M. %A Read, Carlos G. %A Crompton, J. Chance %A Biacchi, Adam J. %A Popczun, Eric J. %A Gordon, Thomas R. %A Lewis, Nathan S. %A Schaak, Raymond E. %D 2014 %T Electrocatalytic and Photocatalytic Hydrogen Production from Acidic and Neutral-pH Aqueous Solutions Using Iron Phosphide Nanoparticles %U https://acs.figshare.com/articles/journal_contribution/Electrocatalytic_and_Photocatalytic_Hydrogen_Production_from_Acidic_and_Neutral_pH_Aqueous_Solutions_Using_Iron_Phosphide_Nanoparticles/2232217 %R 10.1021/nn5048553.s001 %2 https://acs.figshare.com/ndownloader/files/3868147 %K phosphide %K cm %K solution %K 1.0 M phosphate %K FeP nanoparticles %K acidic %K 0.50 M H 2SO %K HER %K mV %K Photocatalytic Hydrogen Production %K UV %X Nanostructured transition-metal phosphides have recently emerged as Earth-abundant alternatives to platinum for catalyzing the hydrogen-evolution reaction (HER), which is central to several clean energy technologies because it produces molecular hydrogen through the electrochemical reduction of water. Iron-based catalysts are very attractive targets because iron is the most abundant and least expensive transition metal. We report herein that iron phosphide (FeP), synthesized as nanoparticles having a uniform, hollow morphology, exhibits among the highest HER activities reported to date in both acidic and neutral-pH aqueous solutions. As an electrocatalyst operating at a current density of −10 mA cm–2, FeP nanoparticles deposited at a mass loading of ∼1 mg cm–2 on Ti substrates exhibited overpotentials of −50 mV in 0.50 M H2SO4 and −102 mV in 1.0 M phosphate buffered saline. The FeP nanoparticles supported sustained hydrogen production with essentially quantitative faradaic yields for extended time periods under galvanostatic control. Under UV illumination in both acidic and neutral-pH solutions, FeP nanoparticles deposited on TiO2 produced H2 at rates and amounts that begin to approach those of Pt/TiO2. FeP therefore is a highly Earth-abundant material for efficiently facilitating the HER both electrocatalytically and photocatalytically. %I ACS Publications