Effect of film morphology on water oxidation enhancement in NiFeCo modified hematite photoanodes
| Autor: | Nader Sobhkhiz Vayghan, Behrooz Eftekharinia, Ali Dabirian, Ali Esfandiar |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Annealing (metallurgy) Band gap 02 engineering and technology Surfaces and Interfaces General Chemistry Electrolyte Hematite 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electron beam physical vapor deposition 0104 chemical sciences Surfaces Coatings and Films Chemical engineering visual_art Materials Chemistry visual_art.visual_art_medium Water splitting Thin film 0210 nano-technology Porosity |
| Zdroj: | Surface and Coatings Technology. 421:127362 |
| ISSN: | 0257-8972 |
| DOI: | 10.1016/j.surfcoat.2021.127362 |
| Popis: | Hematite (α-Fe2O3) is a promising candidate for water oxidation applications due to its abundance in the earth crust and its suitable bandgap. However, hematite performance is severely limited by electron-hole recombination at its interface with the electrolyte; something that can be addressed using electrocatalysts. In this report, we evaluate the influence of a ternary NiFeCo co-catalyst to enhance the water oxidation performance of hematite photoanodes. Thus, NiFeCo co-catalyst is optimized for hematite thin films with i) dense and ii) porous (nano-rod) morphologies. Both hematite films are prepared using electron beam evaporation method followed by an annealing step and NiFeCo co-catalyst is processed using electrodeposition. The results demonstrate optimal thickness of NiFeCo co-catalyst is thinner for porous hematite layers relative to the dense ones indicating that the optimal condition of the co-catalyst is affected by hematite morphology. The optimized dense NiCoFe/hematite photoanode shows nearly than 2.8-fold enhancement relative to the pristine hematite photoanode, whereas the optimized porous NiCoFe/hematite photoanode shows 2.2-fold enhancements. Transient photocurrent measurements confirm that NiFeCo facilitates hole injection from hematite into the electrolyte. These findings have important implications for optimizing electrocatalysts for photoelectrochemical water splitting photoanodes and taking into account the effect of surface morphology. |
| Databáze: | OpenAIRE |
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