The development of clean and renewable energy is necessary due to environmental problems originating from fossil fuels. One potential solution is hydrogen-based technologies because of its high energy density and environmental friendliness. Using electrocatalytic water splitting, electricity can be transformed into hydrogen. Currently, noble metal catalysts such as platinum are the most efficient for the hydrogen evolution reaction (HER), but they are limited in large-scale applications due to scarcity and costs. Current research on sustainable energy is focused on replacing noble metals with inexpensive, metal-based catalysts. Metal sulfides are promising candidates for the HER reaction due to their excellent catalytic activity and stability. However, the main limitation is their inert basal planes and thus HER activity is restricted solely to edge-sites. Recently, we reported the HER activity of another potential candidate, Fe3GeTe2 (FGT), a van der Waals (vdW) material which exhibited both basal plane and edge site activity. Sonicated FGT that was compressed by spark plasma sintering (SPS) yielded the greatest activity relative to the bulk and sonicated forms by providing the most electrode coverage. Expanding on this, we now report on the HER activity of Fe5Ge2Te2 (FG2T), a material analogous to FGT, but with an extra “Fe2Ge” layer sandwiched between two layers of Te atoms. FG2T was synthesized via a solid-state reaction and characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) mapping. Using a sonicated SPS sample, we show that FG2T requires an overpotential of −90.5 mV to drive a current density of 10 mA/cm2, a 13% increase compared to FGT. Density functional theory (DFT) revealed more active sites versus FGT, strengthening the idea of the continued screening of iron-based vdW materials.

Iron rich layered chalcogenide Fe5Ge2Te2 for highly efficient hydrogen evolution

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.