Journal article
Tunable Synthesis of Metal-Rich and Phosphorus-Rich Nickel Phosphides and Their Comparative Evaluation as Hydrogen Evolution Electrocatalysts
Inorganic chemistry, Vol.62(12), pp.4947-4959
03/27/2023
DOI: 10.1021/acs.inorgchem.2c04448
PMID: 36898368
Abstract
Flexible synthetic routes to crystalline metal-rich to phosphorus-rich nickel phosphides are highly desired for comparable electrocatalytic HER studies. This report details solvent-free, direct, and tin-flux-assisted synthesis of five different nickel phosphides from NiCl2 and phosphorus at moderate temperatures (500 °C). Direct reactions are thermodynamically driven via PCl3 formation and tuned through reaction stoichiometry to produce crystalline Ni–P materials from metal-rich (Ni2P, Ni5P4) to phosphorus-rich (cubic NiP2) compositions. A tin flux in NiCl2/P reactions allows access to monoclinic NiP2 and NiP3. Intermediates in tin flux reactions were isolated to help identify phosphorus-rich Ni–P formation mechanisms. These crystalline micrometer-sized nickel phosphide powders were affixed to carbon-wax electrodes and investigated as HER electrocatalysts in acidic electrolyte. All nickel phosphides show moderate HER activity in a potential range of −160 to −260 mV to achieve current densities of 10 mA/cm2 ordered as c-NiP2 ≥ Ni5P4 > NiP3 > m-NiP2 > Ni2P, with NiP3 activity showing some particle size influence. Phosphorus-rich c/m-NiP2 appears most stable under acidic conditions during extended reactions. The HER activity of these different nickel phosphides appears influenced by a combination of factors such as particle size, phosphorus content, polyphosphide anions, and surface charge.
Details
- Title: Subtitle
- Tunable Synthesis of Metal-Rich and Phosphorus-Rich Nickel Phosphides and Their Comparative Evaluation as Hydrogen Evolution Electrocatalysts
- Creators
- Ishanka A Liyanage - University of IowaAshley V Flores - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242 United StatesEdward G Gillan - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242 United States
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.62(12), pp.4947-4959
- Publisher
- American Chemical Society
- DOI
- 10.1021/acs.inorgchem.2c04448
- PMID
- 36898368
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Grant note
- DOI: 10.13039/100000165, name: National Science Foundation, award: 1954676; DOI: 10.13039/100008893, name: University of Iowa
- Language
- English
- Electronic publication date
- 03/10/2023
- Date published
- 03/27/2023
- Academic Unit
- Chemistry
- Record Identifier
- 9984375352402771
Metrics
8 Record Views