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Surface - Gated Charge Carrier - Selective Nanocontacts in Photoelectrochemical Catalysis

表面-门控电荷载体-光电化学催化中的选择性纳米接触

基本信息

批准号：
408246589
负责人：
Dr. Sebastian Zeki Oener, Ph.D.
金额：
--
依托单位：
Department of Chemistry and Biochemistry
依托单位国家：
德国
项目类别：
Research Fellowships
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/408246589?language=en
关键词：
Surface Gated Charge Carrier Selective

项目摘要

The transition from fossil fuels to a sustainable energy infrastructure is impeded by the lack of chemical fuels with high energy-to-weight ratios made from renewable energies. Energy-dense fuels are needed for long-term energy storage (from seasons to years) and for long-distance or heavy-duty transportation.Photoelectrochemical water splitting is a direct route to store the sunlight’s energy in the chemical fuels hydrogen and oxygen gas. Recently, an interdisciplinary team from the USA (Caltech) and Germany (TU Ilmenau, Fraunhofer ISE, Helmholtz Zentrum Berlin) realized a system with an impressive solar-to-hydrogen efficiency of 19%, i.e. with 85% of the maximum theoretical efficiency achievable for the semiconductors used.The presented results clearly prove the feasibility of converting sunlight directly and efficiently into hydrogen and oxygen, however they lack one important ingredient required for an application: long-term stability. For stable operation the semiconductor must be protected from corrosion in harsh aqueous electrolyte solutions while the catalyst integrity is maintained. Stability issues represent the most significant challenge facing practical devices.To prevent corrosion, semiconductor surfaces are often coated conformably with a thermodynamically stable oxide film. This film must not only provide chemical protection but also electrical transport between semiconductor and electrocatalyst. This creates a fundamental trade-off: thick or non-conductive films can prevent corrosion but those do not sufficiently conduct current.During my PhD, I developed new charge carrier-selective contacts for nanowire solar cells based on the surface-gating/pinch-off effect. Those contacts use a surface layer to control the carrier-selectivity of an adjacent metal nanoscale point contact (by donating or accepting charge carriers), while the metal point contact itself facilitates the carrier extraction. Here I propose to use those nanoscale point contacts in water-splitting devices. Such contacts are predicted to generate large photovoltages, and hence high performances due to the “pinch-off” effect. Importantly, they can be surrounded by a thick (100 nm – 1 µm) and even non-conductive oxide layer for robust chemical protection while simultaneously guaranteeing sufficient electrical transport, a combination of properties that seems out of reach for conventional geometries. The work consists of two specific aims. In the first, I will study fundamental aspects of the “pinch-off” effect in model systems. In the second, I will apply the new fundamental knowledge to develop a high-performance, but chemically robust, carrier-collecting nanostructured interface using area-selective oxide deposition methods.To accomplish the work I will combine my expertise in nanofabrication and nanoscale interface properties from my PhD with the world-leading expertise on semiconductor-catalyst interfaces of the American host, Prof. Shannon Boettcher.

从化石燃料向可持续能源基础设施的过渡因缺乏由可再生能源制成的具有高能量重量比的化学燃料而受到阻碍。高能量密度的燃料需要长期的能量储存（从季节到年）和长距离或重载运输。光电化学水分解是将太阳能储存在化学燃料氢气和氧气中的直接途径。最近，一个来自美国（加州理工学院）和德国的跨学科团队（TU Ilmenau，Fraunhofer伊势，Helmholtz Zentrum柏林）实现了一个系统，其太阳能转化为氢气的效率达到了令人印象深刻的19%，即所用半导体可达到的最大理论效率的85%。所呈现的结果清楚地证明了将太阳光直接有效地转化为氢气和氧气的可行性，然而，它们缺乏应用所需的一个重要成分：长期稳定性。为了稳定运行，必须保护半导体免受苛刻的电解质水溶液的腐蚀，同时保持催化剂的完整性。稳定性问题是实际器件面临的最大挑战。为了防止腐蚀，半导体表面通常涂敷一层稳定的氧化膜。该膜不仅必须提供化学保护，还必须提供半导体和电催化剂之间的电传输。这就产生了一个基本的权衡：厚的或不导电的薄膜可以防止腐蚀，但这些薄膜不能充分传导电流。在我的博士学位期间，我开发了基于表面选通/夹断效应的纳米线太阳能电池的新的电荷载流子选择性接触。这些接触使用表面层来控制相邻金属纳米级点接触的载流子选择性（通过贡献或接受电荷载流子），而金属点接触本身促进载流子提取。在这里，我建议在水分解装置中使用这些纳米级的点接触。这样的接触被预测为产生大的光电压，并且因此由于“夹断”效应而产生高性能。重要的是，它们可以被厚（100 nm - 1 µm）甚至不导电的氧化层包围，以提供强大的化学保护，同时保证足够的电传输，这是传统几何形状似乎无法实现的特性组合。这项工作包括两个具体目标。在第一部分中，我将研究模型系统中“夹断”效应的基本方面。在第二部分中，我将应用新的基础知识，使用区域选择性氧化物沉积方法开发一种高性能，但化学稳定的载体收集纳米结构界面。为了完成这项工作，我将联合收割机结合我在纳米纤维和纳米界面特性方面的博士学位和美国主持人Shannon Boettcher教授在催化剂-催化剂界面方面的世界领先的专业知识。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Accelerating water dissociation in bipolar membranes and for electrocatalysis

DOI：
10.1126/science.aaz1487
发表时间：
2020-08-28
期刊：
SCIENCE
影响因子：
56.9
作者：
Oener, Sebastian Z.;Foster, Marc J.;Boettcher, Shannon W.
通讯作者：
Boettcher, Shannon W.

Integrated Reference Electrodes in Anion-Exchange-Membrane Electrolyzers: Impact of Stainless-Steel Gas-Diffusion Layers and Internal Mechanical Pressure

DOI：
10.1021/acsenergylett.0c02338
发表时间：
2020-12
期刊：
ACS Energy Letters
影响因子：
22
作者：
Qiucheng Xu;Sebastian Z. Oener;Grace A Lindquist;Hao Jiang;Chunzhong Li;S. Boettcher
通讯作者：
Qiucheng Xu;Sebastian Z. Oener;Grace A Lindquist;Hao Jiang;Chunzhong Li;S. Boettcher

Nanoscale semiconductor/catalyst interfaces in photoelectrochemistry