Abstract
Development of cost-effective, highly active and durable electrocatalysts is highly demanded for oxygen evolution reaction (OER), which is an indispensable process involved in water splitting cells and metal-air batteries. Here, we accelerate the sluggish OER kinetics by controlling the morphology and engineering electronic structure of Fe x Ni 1-x Se 2 catalysts. Fe x Ni 1-x Se 2 nanotubes with tunable stoichiometry were fabricated through the removal of sacrificial templates (Cu 2 O nanowires) and subsequent low-temperature selenization process. By precise tuning of Fe doping amount in Fe x Ni 1-x Se 2 nanotubes, the optimized Fe 0.125 Ni 0.875 Se 2 nanotubes show a low overpotential of 253 mV at a current density of 10 mA cm −2 , a small Tafel slope of 49 mV dec −1 , and superior durability. By combining analysis of the experimental results with density-functional-theory (DFT) simulations, we reveal that the in-situ formed amorphous hydroxyl group layers on the surface of Fe 0.125 Ni0 .875 Se 2 (Fe 0.125 Ni 0.875 Se 2 –OH) enable highly efficient oxygen evolution catalysis. The Fe dopant can achieve a near-optimal adsorption energy for OER intermediates (OH* O* and OOH*) on the oxidized surface of Fe 0.125 Ni 0.875 Se 2 –OH, which is responsible to the enhanced OER performance of Fe 0.125 Ni 0.875 Se 2 . This work paves a new way for exploring low cost and highly active OER electrocatalysts based on ternary metal selenides with hollow structure.
Original language | English |
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Pages (from-to) | 89-96 |
Number of pages | 8 |
Journal | Materials Today Energy |
Volume | 11 |
DOIs | |
Publication status | Published - 1 Mar 2019 |
Keywords
- Bimetal selenide
- Charge density
- Nanotubes
- Oxygen evolution reaction
- Surface oxidized layers
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science (miscellaneous)
- Nuclear Energy and Engineering
- Fuel Technology
- Energy Engineering and Power Technology