Recent advances in energy-saving chemiresistive gas sensors: A review

After the introduction and justification of several more or less well known and complicated conversion topologies based on series resonance, this chapter will focus on the design of the non-reversible series resonant converter. Following this, a brief description will be given concerning a collection of DC/DC and DC/AC converters developed under various industrial contracts by the Laboratoire d’Electrotechnique et d’Electronique Industrielle (L.E.E.L), Toulouse, France.

Design and Applications

This paper presents an overview of semiconductor materials used in gas sensors, their technology, design, and application. Semiconductor materials include metal oxides, conducting polymers, carbon nanotubes, and 2D materials. Metal oxides are most often the first choice due to their ease of fabrication, low cost, high sensitivity, and stability. Some of their disadvantages are low selectivity and high operating temperature. Conducting polymers have the advantage of a low operating temperature and can detect many organic vapors. They are flexible but affected by humidity. Carbon nanotubes are chemically and mechanically stable and are sensitive towards NO and NH3, but need dopants or modifications to sense other gases. Graphene, transition metal chalcogenides, boron nitride, transition metal carbides/nitrides, metal organic frameworks, and metal oxide nanosheets as 2D materials represent gas-sensing materials of the future, especially in medical devices, such as breath sensing. This overview covers the most used semiconducting materials in gas sensing, their synthesis methods and morphology, especially oxide nanostructures, heterostructures, and 2D materials, as well as sensor technology and design, application in advance electronic circuits and systems, and research challenges from the perspective of emerging technologies.

https://www.mdpi.com/1424-8220/20/22/6694/pdf

Semiconductor Gas Sensors: Materials, Technology, Design, and Application

Stretchable strain sensors have received intensive attention recently due to their widespread potentials in the fields of healthcare monitoring, soft robotics, and electronic skin. Besides high stretchability and excellent sensing properties, the transparency of the sensor is another important parameter when designing multi-functional sensors in reality. In this review paper, we mainly focused on the different strategies to realize the transparency of stretchable strain sensor. Some typical advances in different types of stretchable and transparent strain sensors as well as their mechanisms, sensing properties, and applications are summarized. Finally, the open question and possible solution in this field have also been showcased.

Advances in transparent and stretchable strain sensors

This article discusses the main uses of 1D and 2D nanomaterials in the development of conductometric gas sensors based on metal oxides. It is shown that, along with the advantages of these materials, which can improve the parameters of gas sensors, there are a number of disadvantages that significantly limit their use in the development of devices designed for the sensor market.

Current Trends in Nanomaterials for Metal Oxide-Based Conductometric Gas Sensors: Advantages and Limitations. Part 1: 1D and 2D Nanostructures.

In this work, commercial anatase TiO2 powders were modified using ultrathin Fe2O3 layer by atomic layer deposition (ALD). The ultrathin Fe2O3 coating having small bandgap of 2.20 eV can increase the visible light absorption of TiO2 supports, at the meantime, Fe2O3/TiO2 heterojunction can effectively improve the lifetime of photogenerated electron–hole pairs. Results of ALD Fe2O3 modified TiO2 catalyst, therefore, showed great visible light driven catalytic degradation of methyl orange compared to pristine TiO2. A 400 cycles of ALD Fe2O3 (~ 2.6 nm) coated TiO2 powders exhibit the highest degradation efficiency of 97.4% in 90 min, much higher than pristine TiO2 powders of only 12.5%. Moreover, an ultrathin ALD Al2O3 (~ 2 nm) was able to improve the stability of Fe2O3-TiO2 catalyst. These results demonstrate that ALD surface modification with ultrathin coating is an extremely powerful route for the applications in constructing efficient and stable photocatalysts.

/pdf/enhanced-visible-light-photocatalytic-activity-of-fe-2-o-3-1zvnw4ytji.pdf

Enhanced visible light photocatalytic activity of Fe 2 O 3 modified TiO 2 prepared by atomic layer deposition

https://iopscience.iop.org/article/10.1149/1945-7111/ab7e23/pdf

Review—Resistive-Type Hydrogen Sensors Based on Zinc Oxide Nanostructures

Silicon is considered as a blooming candidate material for next-generation lithium-ion batteries due to its low electrochemical potential and high theoretical capacity. However, its commercialization has been impeded by the poor cycling issue associated with severe volume changes (∼380%) upon (de)lithiation. Herein, an organic-inorganic hybrid film of titanicone via molecular layer deposition (MLD) is proposed as an artificial solid electrolyte interphase (SEI) layer for Si anodes. This rigid-soft titanicone coating with Young's modulus of 21 GPa can effectively relieve stress concentration during the lithiation process, guaranteeing the stability of the mechanical structure of a Si nanoparticles (NPs)@titanicone electrode. Benefiting from the long-strand (Ti-O-benzene-O-Ti-) unit design, the optimized Si NPs@70 cycle titanicone anode delivers a high Li+ diffusion coefficient and a low Li+ diffusion barrier, as revealed by galvanostatic intermittent titration (GITT) investigations and density functional theory (DFT) simulations, respectively. Ultimately, the Si NPs@70 cycle titanicone electrode shows high initial Coulombic efficiency (84%), long cycling stability (957 mAh g-1 after 450 cycles at 1 A g-1), a stable SEI layer, and good rate performances. The molecular-scale design of the titanicone-protected Si anodes may bring in new opportunities to realize the next-generation lithium-ion batteries as well as other rechargeable batteries.

Tailoring Stress and Ion-Transport Kinetics via a Molecular Layer Deposition-Induced Artificial Solid Electrolyte Interphase for Durable Silicon Composite Anodes.

A stretchable petal patterned strain sensor comprising Ir nanoparticles-modified multi-walled carbon nanotubes for human-motion detection

Lithium-ion batteries with conversion-type anode electrodes have attracted increasing interest in providing higher energy storage density than those with commercial intercalation-type electrodes. However, conversion-type materials exhibit severe structural instability and capacity fade during cycling. In this work, a molecular layer deposition (MLD)-derived conductive Al2O3/carbon layer was employed to stabilize the structure of the cactus-like NiCo2O4 nanocrystal (NC) anode. The conductive Al2O3/carbon network and cactus-like NiCo2O4 NCs are beneficial for fast Li+/e− transport. Moreover, the Al2O3/carbon buffer-layer can prevent the NiCo2O4 NCs from agglomeration and form a steady solid electrolyte interphase (SEI), thus hampering the penetration of the electrolyte. Owing to these advantages, the assembled NiCo2O4@Al2O3/carbon half battery shows a high reversible capacity (931.2 mA h g−1 at 2 A g−1) and long-term stability of 290 mA h g−1 at 5 A g−1 over 500 cycles. Quantitative analyses further reveal the fast kinetics and the capacitance-battery dual model mechanism in the 3D core–shell structures. The design and introduction of MLD-derived hybrid coating may open a new way to conversion-type and alloy-type anode materials beyond NiCo2O4 to achieve high cyclability.

Qiang Ren

Papers

Enhanced visible light photocatalytic activity of Fe 2 O 3 modified TiO 2 prepared by atomic layer deposition

Review—Resistive-Type Hydrogen Sensors Based on Zinc Oxide Nanostructures

Tailoring Stress and Ion-Transport Kinetics via a Molecular Layer Deposition-Induced Artificial Solid Electrolyte Interphase for Durable Silicon Composite Anodes.

A stretchable petal patterned strain sensor comprising Ir nanoparticles-modified multi-walled carbon nanotubes for human-motion detection

Realizing the enhanced cyclability of a cactus-like NiCo2O4 nanocrystal anode fabricated by molecular layer deposition