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DOI	10.1039/d0ee00356e
	Effects of bubbles on the electrochemical behavior of hydrogen-evolving Si microwire arrays oriented against gravity
	Kempler P.A.; Coridan R.H.; Lewis N.S.; Lewis N.S.
发表日期	2020
ISSN	17545692
起始页码	1808
结束页码	1817
卷号	13 期号:6
英文摘要	The size-distribution, coverage, electrochemical impedance, and mass-transport properties of H2 gas-bubble films were measured for both planar and microwire-array platinized n+-Si cathodes performing the hydrogen-evolution reaction in 0.50 M H2SO4(aq). Inverted, planar n+-Si/Ti/Pt cathodes produced large, stationary bubbles which contributed to substantial increases in ohmic potential drops. In contrast, regardless of orientation, microwire array n+-Si/Ti/Pt cathodes exhibited a smaller layer of bubbles on the surface, and the formation of bubbles did not substantially increase the steady-state overpotential for H2(g) production. Experiments using an electroactive tracer species indicated that even when oriented against gravity, bubbles enhanced mass transport at the electrode surface. Microconvection due to growing and coalescing bubbles dominated effects due to macroconvection of gliding bubbles on Si microwire array cathodes. Electrodes that maintained a large number of small bubbles on the surface simultaneously exhibited low concentrations of dissolved hydrogen and small ohmic potential drops, thus exhibiting the lowest steady-state overpotentials. The results indicate that microstructured electrodes can operate acceptably for unassisted solar-driven water splitting in the absence of external convection and can function regardless of the orientation of the electrode with respect to the gravitational force vector. © The Royal Society of Chemistry.
英文关键词	Drops; Flocculation; Gravitation; Hydrogen; Hydrogen evolution reaction; Silicon; Dissolved hydrogen; Electrochemical behaviors; Electrochemical impedance; Electrode surfaces; External convection; Gravitational forces; Low concentrations; Microstructured electrodes; Cathodes
语种	英语
来源期刊	Energy & Environmental Science
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/189640
作者单位	Division of Chemistry and Chemical Engineering, California Institute of Technology, 127-72, 210 Noyes Laboratory, Pasadena, CA 91125, United States; Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, United States; Beckman Institute, California Institute of Technology, Pasadena, CA 91125, United States
推荐引用方式 GB/T 7714	Kempler P.A.,Coridan R.H.,Lewis N.S.,et al. Effects of bubbles on the electrochemical behavior of hydrogen-evolving Si microwire arrays oriented against gravity[J],2020,13(6).
APA	Kempler P.A.,Coridan R.H.,Lewis N.S.,&Lewis N.S..(2020).Effects of bubbles on the electrochemical behavior of hydrogen-evolving Si microwire arrays oriented against gravity.Energy & Environmental Science,13(6).
MLA	Kempler P.A.,et al."Effects of bubbles on the electrochemical behavior of hydrogen-evolving Si microwire arrays oriented against gravity".Energy & Environmental Science 13.6(2020).