Charge-transfer engineering strategies for tailored ionic conductivity at oxide interfaces

Gunkel, Felix; Christensen, Dennis Valbjørn; Pryds, Nini

doi:10.1039/d0tc01780a

Cited by 9 publications

(7 citation statements)

References 51 publications

(83 reference statements)

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“…Through atomic-level control of synthesis in form of epitaxial thin films and heterostructures it is now possible to create desired combinations of different chemical compositions for perovskite oxides ( Gunkel et al, 2017 ; Baniecki et al, 2019 ). This allows engineering surface cover layers ( Akbashev et al, 2018 ; Heymann et al, 2022 ), and controlling chemical gradients and electronic properties independently via charge-transfer processes ( Gunkel et al, 2020b ; Burton et al, 2022 ) or sub-surface engineering ( Akbashev et al, 2018 ; Zhang et al, 2020 ), and enables a systematic understanding and tuning of activity and degradation from atomically defined model systems ( Weber and Gunkel, 2019 ). This enhanced material control with atomically smooth catalyst surfaces comes at the cost of a minimized contact area between catalyst and electrolyte, limiting the technological relevance of epitaxial systems.…”

Section: Atomistic Understanding Of Activity and Degradation Relies O...mentioning

confidence: 99%

Activity-Stability Relationships in Oxide Electrocatalysts for Water Electrolysis

et al. 2022

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The oxygen evolution reaction (OER) is one of the key kinetically limiting half reactions in electrochemical energy conversion. Model epitaxial catalysts have emerged as a platform to identify structure-function-relationships at the atomic level, a prerequisite to establish advanced catalyst design rules. Previous work identified an inverse relationship between activity and the stability of noble metal and oxide OER catalysts in both acidic and alkaline environments: The most active catalysts for the anodic OER are chemically unstable under reaction conditions leading to fast catalyst dissolution or amorphization, while the most stable catalysts lack sufficient activity. In this perspective, we discuss the role that epitaxial catalysts play in identifying this activity-stability-dilemma and introduce examples of how they can help overcome it. After a brief review of previously observed activity-stability-relationships, we will investigate the dependence of both activity and stability as a function of crystal facet. Our experiments reveal that the inverse relationship is not universal and does not hold for all perovskite oxides in the same manner. In fact, we find that facet-controlled epitaxial La0.6Sr0.4CoO3-δ catalysts follow the inverse relationship, while for LaNiO3-δ, the (111) facet is both the most active and the most stable. In addition, we show that both activity and stability can be enhanced simultaneously by moving from La-rich to Ni-rich termination layers. These examples show that the previously observed inverse activity-stability-relationship can be overcome for select materials and through careful control of the atomic arrangement at the solid-liquid interface. This realization re-opens the search for active and stable catalysts for water electrolysis that are made from earth-abundant elements. At the same time, these results showcase that additional stabilization via material design strategies will be required to induce a general departure from inverse stability-activity relationships among the transition metal oxide catalysts to ultimately grant access to the full range of available oxides for OER catalysis.

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Section: Atomistic Understanding Of Activity and Degradation Relies O...mentioning

confidence: 99%

Activity-Stability Relationships in Oxide Electrocatalysts for Water Electrolysis

et al. 2022

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“…Research and development efforts toward nanoscale manipulation of ionic properties of materials principally allow realizing micro-scale membranes and exchange electrodes, building a fully operational fuel cell on the micrometer lengths scale. In addition to that, a vast variety of research is devoted to harvesting nanoscale materials science for improved fuel cell performance, including tailored nano-composite materials [351][352][353] and heterogeneously layered superlattices [354][355][356][357][358], or interface concepts with tailored ion conduction along and across interfaces [357,[359][360][361]. The interested reader is referred to Garbayo et al [362], Wen et al [363] and Shin et al [364] for more details on the strategies for improving the performances of electrode and electrolyte thin films for µSOFC.…”

Section: Methodsmentioning

confidence: 99%

Powering internet-of-things from ambient energy: a review

et al. 2023

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Internet-of-thing (IoT) is an assembly of devices that collect and share data with other devices and communicate via the internet. This massive network of devices, generates and communicates data and is the key to the value in IoT, allowing access to raw information, gaining insight, and making an intelligent decisions. Today, there are billions of IoT devices such as sensors and actuators deployed. Many of these applications are easy to connect, but those tucked away in hard-to-access spots will need to harvest ambient energy. Therefore, the aim is to create devices that are self-report in real-time. Efforts are underway to install a self-powered unit in IoT devices that can generate sufficient power from environmental conditions such as light, vibration, and heat. In this review paper, we discuss the recent progress made in materials and device development in power- and, storage units, and power management relevant for IoT applications. This review paper will give a comprehensive overview for new researchers entering the field of IoT and a collection of challenges as well as perspectives for people already working in this field.

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“…[20,44,47] Therefore, establishing tunable strains and strain gradients in complex oxides via reconfiguration-driven assembly is a viable approach to tailor ionic and electronic transports in oxide-based devices on conventional semiconductor substrates. [48,49]…”

Section: Assembly and Strain Fields In Srtio 3 /Laalo 3 Nanomembranesmentioning

confidence: 99%

Reconfiguration of Amorphous Complex Oxides: A Route to a Broad Range of Assembly Phenomena, Hybrid Materials, and Novel Functionalities

Prakash

Chen

Debasu

et al. 2021

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materials that are freestanding either at a stage in their fabrication, in their final state, or both. [1] NMs with thicknesses in the range of a few nanometers to a few hundred nanometers can be isolated from their substrates through synthesis and processing techniques that have become established in the last 20 years. [1][2][3][4][5] The lateral dimensions of NMs are at least two orders of magnitude larger than their thickness, making them a distinctive platform from 0D, 1D, and bulk materials. [6] NMs enable a vast range of possibilities, including i) the capability to subject materials to elastic strain fields with magnitudes or geometries that are not realizable in bulk materials or by direct growth; [7][8][9] ii) unique and rapid characterization of materials properties and kinetic processes; [10,11] iii) heterogeneous integration of materials via controlled transfer, including, into environments in which the NM materials would be otherwise inaccessible via synthesis; [12,13] iv) 3D structures that can be processed in parallel on large-area substrates and can find use in several applications. [14][15][16][17][18] The scope of applications and phenomena that benefit from NMs can be extended to a new spectrum of materials Reconfiguration of amorphous complex oxides provides a readily controllable source of stress that can be leveraged in nanoscale assembly to access a broad range of 3D geometries and hybrid materials. An amorphous SrTiO 3 layer on a Si:B/Si 1−x Ge x :B heterostructure is reconfigured at the atomic scale upon heating, exhibiting a change in volume of ≈2% and accompanying biaxial stress. The Si:B/Si 1−x Ge x :B bilayer is fabricated by molecular beam epitaxy, followed by sputter deposition of SrTiO 3 at room temperature. The processes yield a hybrid oxide/semiconductor nanomembrane. Upon release from the substrate, the nanomembrane rolls up and has a curvature determined by the stress in the epitaxially grown Si:B/Si 1−x Ge x :B heterostructure. Heating to 600 °C leads to a decrease of the radius of curvature consistent with the development of a large compressive biaxial stress during the reconfiguration of SrTiO 3 . The control of stresses via post-deposition processing provides a new route to the assembly of complex-oxide-based heterostructures in 3D geometry. The reconfiguration of metastable mechanical stressors enables i) synthesis of various types of strained superlattice structures that cannot be fabricated by direct growth and ii) technologies based on strain engineering of complex oxides via highly scalable lithographic processes and on large-area semiconductor substrates.The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.202105424.

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Charge-transfer engineering strategies for tailored ionic conductivity at oxide interfaces

Abstract: Based on the example of the p-type LaAlO3/SrTiO3 interface, we discuss charge-transfer phenomena that tailor the ionic conductivity along oxide heterointerfaces, by providing a confined space-charge layer as channel for oxygen ion conduction.

Cited by 9 publications

References 51 publications

Activity-Stability Relationships in Oxide Electrocatalysts for Water Electrolysis

Activity-Stability Relationships in Oxide Electrocatalysts for Water Electrolysis

Powering internet-of-things from ambient energy: a review

Reconfiguration of Amorphous Complex Oxides: A Route to a Broad Range of Assembly Phenomena, Hybrid Materials, and Novel Functionalities

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