Photoelectrochemical Solar Energy Conversion and Electrocatalysis Using Earth-Abundant Nanomaterials

Tuesday, October 13, 2015: 15:50
104-B (Phoenix Convention Center)
S. Jin (Department of Chemistry, UW-Madison)
The scale of renewable energy challenge not only calls for highly efficient technologies but also abundant, inexpensive, and robust materials. Nanomaterials can help to mitigate the poor properties of earth-abundant semiconductors and catalysts to enhance solar energy conversion. We have controlled the nanostructures and polymorphs of layered MS2 (M = Mo, W) materials and other earth-abundant metal chalcogenides, such as metallic cobalt pyrite (CoS2), to significantly enhance their catalytic activity in hydrogen evolution reaction (HER). We further establish ternary pyrite-type cobalt phosphosulfide (CoPS) as a high-performance earth-abundant HER catalyst that achieves geometrical catalytic current density of 10 mA/cm2 at overpotentials as low as 48 mV with outstanding long-term operation stability. These earth-abundant catalysts and semiconductors have been integrated to enable efficient solar energy conversion. Integrated photocathodes of the novel earth-abundant catalysts on n+-p-p+ silicon micropyramids achieved high photocurrents up to 35 mA/cm2 and onset photovoltages as high as 450 mV vs RHE, and 5-6% solar-to-hydrogen conversion efficiency.