Ginkgo Leaf ‐Derived Carbon Supports for the Immobilization of Iron/Iron Phosphide Nanospheres for Electrocatalytic Hydrogen Evolution

Iron-catalyzed graphitization with subsequent phosphidation is used to prepare Gingko-leaf derived carbon-supports immobilized with iron and iron phosphide nanospheres. The most active catalyst shows excellent performance in the hydrogen evolution reaction (HER) in 0.5  m H2SO4, achieving a current density of 10 and 500  mA cm−2 at overpotentials of 92 and 346  mV, respectively. AbstractIron/iron phosphide nanospheres supported on ginkgo leaf-derived carbon (Fe&FeP@gl-C) are prepared using a post-phosphidation approach, with varying amounts of iron (Fe). The activity of the catalysts in the hydrogen evolution reaction (HER) outperforms iron/iron carbide nanospheres supported on ginkgo leaf-derived carbon (Fe&FexC@gl-C), due to enhanced work function, electron transfer, and Volmer processes. The d-band centers of Fe&FeP@gl-C-15 move away from the Fermi level, lowering the H2 desorption energy and accelerating the Heyrovsky reaction. Density functional theory (DFT) calculations reveal that the hydrogen-binding free energy | ΔGH*| value is close to zero for the Fe&FeP@gl-C-15 catalyst, showing a good balance between Volmer and Heyrovsky processes. The Fe&FeP@gl-C-15 catalyst shows excellent hydrogen evolution performance in 0.5  m H2SO4, driving a current density of 10  mA cm−2 at an overpotential of 92  mV. Notably, the Fe&FeP@gl-C-15 catalyst outperforms a 20  wt% Pt/C catalyst, with a smaller overpotential required to drive a higher current density above 375 mA...

Source: Small - January 4, 2024 Category: Nanotechnology Authors: Qichang Wang, Zhaofu Fei, Dekui Shen, Chongbo Cheng, Paul J. Dyson Tags: Research Article Source Type: research