title: p-Si/W2C and p-Si/W2C/Pt photocathodes for the hydrogen evolution reaction.
abstract: p-Si/W2C photocathodes are synthesized by evaporating tungsten metal in an ambient of ethylene gas to form tungsten semicarbide (W2C) thin films on top of p-type silicon (p-Si) substrates. As deposited the thin films contain crystalline W2C with a bulk W:C atomic ratio of approximately 2:1. The W2C films demonstrate catalytic activity for the hydrogen evolution reaction (HER), and p-Si/W2C photocathodes produce cathodic photocurrent at potentials more positive than 0.0 V vs RHE while bare p-Si photocathodes do not. The W2C films are an effective support for Pt nanoparticles allowing for a considerable reduction in Pt loading. p-Si/W2C/Pt photocathodes with Pt nanoparticles achieve photocurrent onset potentials and limiting photocurrent densities that are comparable to p-Si/Pt photocathodes with Pt loading nine times higher. This makes W2C an earth abundant alternative to pure Pt for use as an electrocatalyst on photocathodes for the HER.
authors.affiliation: Department of Chemical Engineering, ‡Department of Chemistry and Biochemistry, Center for Electrochemistry, §Texas Materials Institute, and Center for Nano- and Molecular Science, University of Texas at Austin , 1 University Station C0400, Austin, Texas 78712-0231, United States.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Berglund
authors.forename: Huichao
authors.initials: H
authors.lastname: He
authors.forename: William D
authors.initials: WD
authors.lastname: Chemelewski
authors.forename: Hugo
authors.initials: H
authors.lastname: Celio
authors.forename: Andrei
authors.initials: A
authors.lastname: Dolocan
authors.forename: C Buddie
authors.initials: CB
authors.lastname: Mullins