Understanding the Photoelectrochemical Properties of Theoretically Predicted Water-Splitting Catalysts for Effective Materials Discovery

摘要

Data-intensive discovery of water-splitting catalysts can accelerate thedevelopment of sustainable energy technologies, such as the photocatalyticand/or electrocatalytic production of renewable hydrogen fuel. Throughcomputational screening, 13 materials were recently predicted as potentialwater-splitting photocatalysts: Cu_3NbS_4, CuYS_2, SrCu_2O_2, CuGaO_2,Na_3BiO_4, Sr_2PbO_4, LaCuOS, LaCuOSe, Na_2TeO_4, La4O_4Se_3, Cu_2WS_4,BaCu_2O_2, and CuAlO_2. Herein, these materials are synthesized, their bandgapsand band alignments are experimentally determined, and their photoelectrocatalytichydrogen evolution properties are assessed. Using cyclicvoltammetry and chopped illumination experiments, 9 of the 13 materialsare experimentally found to have bandgaps and band alignments thatstraddle the potentials required for the oxygen evolution reaction (OER) andhydrogen evolution reaction (HER), as computationally predicted. Duringphotocatalytic testing, 12 of the materials yield a measurable photocurrent.However, only three are found to be active for the HER, with Cu_3NbS_4,CuYS_2, and Cu_2WS_4 producing H_2 in amounts comparable to bare TiO_2; abenchmark photocatalyst. This study provides experimental validation ofcomputational bandgap and band alignment predictions while also successfullyidentifying active photocatalysts.