Highly efficient hydrogen production using p-Si wire arrays and NiMoZn heterojunction photocathodes
SCIE
SCOPUS
- Title
- Highly efficient hydrogen production using p-Si wire arrays and NiMoZn heterojunction photocathodes
- Authors
- Choi, S.K.; Piao, G.; Choi, W.; Park, H.
- Date Issued
- 2017-11
- Publisher
- Elsevier B.V.
- Abstract
- Highly efficient photoelectrochemical (PEC) hydrogen production is achieved using p-Si wire arrays loaded with NiMoZn particles in aqueous sulfuric acid under simulated sunlight (AM 1.5 G; 100 mW cm−2). Vertically-aligned wire arrays are grown on planar Si wafers via a quick electroless etching process within 5 min, leading to short Si wires of ∼4 μm and diameters of ∼0.2 μm. Despite the short length of the wires, the reflectance of the arrays is < 5% over the wavelength range of 400–800 nm (the reflectance of planar Si is ∼40%) and the photocurrent density (Iph) is enhanced by ∼ 30% relative to planar Si. To further improve the PEC performance, ∼ 100 nm NiMoZn particles are photoelectrochemically deposited onto the wires. The wire arrays with evenly distributed NiMoZn particles show a photocurrent onset potential (Eon) of ∼ + 0.27 V vs. RHE and produce an Iph of ∼1.45 mA cm−2 at 0 V vs. RHE with a Faradaic efficiency of ∼ 100% for H2 evolution. This Iph value is ∼10-fold greater than that with the planar Si/NiMoZn samples. The excellent performance of the wire arrays and NiMoZn heterojunction is attributed to enhanced light absorption (decreased reflectance), facilitated charge transfer (radial-directional electron transfer), and NiMoZn-catalyzed hydrogen production.
- Keywords
- Electrocatalysts; Field emission cathodes; Heterojunctions; Hydrogen production; Molybdenum alloys; Morphology; Nickel alloys; Photoelectrochemical cells; Reflection; Silicon; Silicon alloys; Silicon wafers; Ternary alloys; Wire; Artificial photosynthesis; Directional electrons; Enhanced light absorptions; Faradaic efficiencies; Photocurrent density; Photoelectrochemicals; Solar fuels; Water splitting; Zinc alloys
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/50769
- DOI
- 10.1016/j.apcatb.2017.06.020
- ISSN
- 0926-3373
- Article Type
- Article
- Citation
- Applied Catalysis B: Environmental, vol. 217, page. 615 - 621, 2017-11
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- There are no files associated with this item.
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