Oxide Research Articles

Multigas Identification by Temperature-Modulated Operation of a Single Anodic Aluminum Oxide Gas Sensor Platform and Deep Learning Algorithm.

Semiconductor metal oxide (SMO) gas sensors are gaining prominence owing to their high sensitivity, rapid response, and cost-effectiveness. These sensors detect changes in resistance resulting from oxidation-reduction reactions with target gases, responding to a variety of gases simultaneously. However, their inherent limitations lie in selectivity. Despite attempts to address this through new sensing materials and filters, achieving perfect selectivity remains challenging. This study addresses the selectivity issue by implementing temperature-modulated operation of a single SMO gas sensor utilizing an anodic aluminum oxide (AAO) microheater platform. The AAO-based sensor ensures a high thermal and mechanical stability during prolonged temperature modulation. A staircase waveform featuring six temperature conditions was applied to the microheater platform, and gas response data were collected for acetone, ammonia, ethanol, and nitrogen dioxide. Leveraging a convolutional neural network (CNN), gas patterns were trained and used to predict gas types and concentrations. The results demonstrated a high classification accuracy of 97.0%, with mean absolute percentage errors (MAPE) for concentration estimation of acetone, ammonia, ethanol, and nitrogen dioxide at 13.7, 19.2, 19.8, and 19.4%, respectively. The proposed method effectively classified four spices and accurately distinguished similar odors, which are difficult for human olfaction to differentiate. The results highlight that the combination of temperature modulation and deep learning algorithms proves to be highly effective in precisely determining gas types and concentrations.

Nanoparticle-Doped Antibacterial and Antifungal Coatings.

Antimicrobial polymeric coatings rely not only on their surface functionalities but also on nanoparticles (NPs). Antimicrobial coatings gain their properties from the addition of NPs into a polymeric matrix. NPs that have been used include metal-based NPs, metal oxide NPs, carbon-based nanomaterials, and organic NPs. Copper NPs and silver NPs exhibit antibacterial and antifungal properties. So, when present in coatings, they will release metal ions with the combined effect of having bacteriostatic/bactericidal properties, preventing the growth of pathogens on surfaces covered by these nano-enhanced films. In addition, metal oxide NPs such as titanium dioxide NPs (TiO2 NPs) and zinc oxide NPs (ZnONPs) are used as NPs in antimicrobial polymeric coatings. Under UV irradiation, these NPs show photocatalytic properties that lead to the production of reactive oxygen species (ROS) when exposed to UV radiation. After various forms of nano-carbon materials were successfully developed over the past decade, they and their derivatives from graphite/nanotubes, and composite sheets have been receiving more attention because they share an extremely large surface area, excellent mechanical strength, etc. These NPs not only show the ability to cause oxidative stress but also have the ability to release antimicrobial chemicals under control, resulting in long-lasting antibacterial action. The effectiveness and life spans of the antifouling performance of a variety of polymeric materials have been improved by adding nano-sized particles to those coatings.

Clew-like Cu2O/CuO Microsphere Adsorbents for Highly Efficient Anionic Dye Removal.

Adsorbents with high selectivity and adsorption capacity are of significant interest for the removal of dye pollutants. Herein, we report a facile low-temperature solvothermal synthesis of clew-like Cu2O/CuO microspheres by using cupric acetate monohydrate as the copper resource and ethylene glycol as the solvent and morphology modulator. The synthesized Cu2O/CuO microspheres showed high selective adsorption to anionic dyes (e.g., methyl orange (MO) and Reactive Red 2 (RR2)) rather than to cationic dyes (e.g., methylene blue (MB), Rhodamine B (RhB)). MO was then selected to evaluate the parameters of adsorption due to the adsorbent exhibiting the highest adsorption capacity for MO. We demonstrate that the adsorption of MO by Cu2O/CuO microspheres has a good correlation with the pseudo-second-order model and Langmuir isotherm with a maximum adsorption capacity of 826.45 mg/g, which is higher than that of previously reported metal oxide material adsorbents. The excellent adsorption ability of clew-like Cu2O/CuO microspheres to MO may be attributed to the synergistic effects of electrostatic attraction, unique hierarchical structure, and crystal defects of the prepared Cu2O/CuO microspheres. We believe our work provides new insight into the synthesis of high-performance adsorbents.

Sensorless Junction Temperature Estimation of Onboard SiC MOSFETs Using Dual-Gate-Bias-Triggered Third-Quadrant Characteristics.

Silicon carbide (SiC) metal oxide semiconductor field-effect transistors (MOSFETs) are a future trend in traction inverters in electric vehicles (EVs), and their thermal safety is crucial. Temperature-sensitive electrical parameters' (TSEPs) indirect detection normally requires additional circuits, which can interfere with the system and increase costs, thereby limiting applications. Therefore, there is still a lack of cost-effective and sensorless thermal monitoring techniques. This paper proposes a high-efficiency datasheet-driven method for sensorless estimation utilizing the third-quadrant characteristics of MOSFETs. Without changing the existing hardware, the closure degree of MOS channels is controlled through a dual-gate bias (DGB) strategy to achieve reverse conduction in different patterns with body diodes. This method introduces a MOSFET operating current that TSEPs are equally sensitive to into the two-argument function, improving the complexity and accuracy. A two-stage current pulse is used to decouple the motor effect in various conduction modes, and the TSEP-combined temperature function is built dynamically by substituting the currents. Then, the junction temperature is estimated by the measured bus voltage and current. Its effectiveness was verified through spice model simulation and a test bench with a three-phase inverter. The average relative estimation error of the proposed method is below 7.2% in centigrade.

Recent Advances in Asymmetric Organometallic Electrochemical Synthesis (AOES).

ConspectusIn recent years, our research group has dedicated significant effort to the field of asymmetric organometallic electrochemical synthesis (AOES), which integrates electrochemistry with asymmetric transition metal catalysis. On one hand, we have rationalized that organometallic compounds can serve as molecular electrocatalysts (mediators) to reduce overpotentials and enhance both the reactivity and selectivity of reactions. On the other hand, the conditions for asymmetric transition metal catalysis can be substantially improved through electrochemistry, enabling precise modulation of the transition metal's oxidation state by controlling electrochemical potentials and regulating the electron transfer rate via current adjustments. This synergistic approach addresses key challenges inherent in traditional asymmetric transition metal catalysis, particularly those related to the use of redox-active chemical reagents. Furthermore, the redox potentials of molecular electrocatalysts can be conveniently tuned by modifying their ligands, thereby governing the reaction regioselectivity and stereoselectivity. As a result, the AOES has emerged as a powerful and promising tool for the synthesis of chiral compounds.In this Account, we summarize and contextualize our recent efforts in the field of AOES. Our primary strategy involves leveraging the controllability of electrochemical potential and current to regulate the oxidation state of organometallics, thereby facilitating the desired reactions. An efficient asymmetric synthesis platform was established under mild conditions, significantly reducing the reliance on chemical redox reagents. Our research has been systematically categorized into three sections based on distinct electrolysis modes: asymmetric transition metal catalysis combined with anodic oxidation, cathodic reduction, and paired electrolysis. In each section, we highlight our innovative discoveries tailored to the unique characteristics of the respective electrolysis modes.In many transformations, transition metal-catalyzed reactions involving traditional chemical redox reagents and those utilizing electrochemistry exhibit similar reactivities. However, we also observed notable differences in certain cases. These findings include the following: (1) Enhanced efficiency in asymmetric electrochemical synthesis: for instance, the Rh-catalyzed enantioselective electrochemical functionalization of C-H bonds demonstrates superior efficiency. (2) Expanded scope of transformations: certain transformations, previously challenging in traditional transition metal catalysis, can be achieved through electrochemistry due to the tunability of redox potentials. A notable example is the enantioselective reductive coupling of aryl chlorides, which significantly expands the range of accessible transformations. Additionally, our mechanistic studies explore unique techniques intrinsic to electrochemistry, such as controlled potential electrolysis experiments, the impact of electrode materials on catalyst performance, and cyclic voltammetry studies. These investigations provide a more intuitive understanding of the behavior of metal catalysts through the study of electrochemical mechanisms, which can also guide the design of new catalytic systems.The advancements in this field offer a robust platform for environmentally friendly and sustainable selective asymmetric transformations. By integrating electrochemistry with transition metal catalysis, we have developed a versatile approach for organic synthesis that not only enhances the efficiency and selectivity of reactions but also reduces the environmental impact. We anticipate that this Account will stimulate further research and innovation in the realm of AOES, leading to the discovery of new catalytic systems and the development of more sustainable synthetic methodologies.

A Robust Dual-Layered Solid Electrolyte Interphase Enabled by Cation Specific Adsorption-Induced Built-In Electrostatic Field for Long-Cycling Solid-State Lithium Metal Batteries.

Solid-state lithium (Li) metal batteries (SSLMBs) are considered as one of the most promising next-generation battery technologies due to their high energy density and intrinsic safety. However, interfacial issues such as side reactions and Li dendrite growth severely hinder the practical application of SSLMBs. In this contribution, we proposed a cationic built-in electrostatic field to drive the generation of an anion-derived dual-layered solid electrolyte interphase (SEI). The specific adsorption of tributylmethyl-phosphonium bis(trifluoromethanesulfonyl)imide (TMPB) cations onto negatively charged Li anode surface significantly prevents interfacial side reactions between vulnerable polyethylene oxide (PEO) and Li metal. More importantly, the formed cationic built-in electrostatic field induces the targeted trapping of Li-salt anions onto the Li metal surface, leading to the generation of an anion-derived dual-layered SEI, composed of a mechanically flexible organic-rich surface layer and a Li-ion conductive inorganic-rich bottom layer. As a result, the Li||Li cell demonstrated an extended lifespan of over 1900 hours with the reduced polarization voltage. The Li||LiFePO4 full cell also exhibited excellent cycling stability, maintaining an average Coulombic efficiency of 99.69% over 200 cycles at 0.5 C. This work provides valuable insights into mitigating interfacial degradation and promoting uniform Li deposition through surface electrostatic field regulation.

Chemoresistive Gas Sensors Based on Noble-Metal-Decorated Metal Oxide Semiconductors for H2 Detection.

Hydrogen has emerged as a prominent candidate for future energy sources, garnering considerable attention. Given its explosive nature, the efficient detection of hydrogen (H2) in the environment using H2 sensors is paramount. Chemoresistive H2 sensors, particularly those based on noble-metal-decorated metal oxide semiconductors (MOSs), have been extensively researched owing to their high responsiveness, low detection limits, and other favorable characteristics. Despite numerous recent studies and reviews reporting advancements in this field, a comprehensive review focusing on the rational design of sensing materials to enhance the overall performance of chemoresistive H2 sensors based on noble-metal-decorated MOFs is lacking. This review aims to address this gap by examining the principles, applications, and challenges of chemoresistive H2 sensors, with a specific focus on Pd-decorated and Pt-decorated MOSs-based sensing materials. The observations and explanations of strategies employed in the literature, particularly within the last three years, have been analyzed to provide insights into the latest research directions and developments in this domain. This understanding is essential for designing and fabricating highly efficient H2 sensors.

Ethanol-Based Transesterification of Rapeseed Oil with CaO Catalyst: Process Optimization and Validation Using Microalgal Lipids

Microalgal oil has been increasingly studied as a feedstock for biodiesel production through transesterification reactions using heterogeneous catalysts. This route offers several benefits, including catalyst reuse, ease of separation, and improved safety, while addressing environmental and technical issues associated with using homogeneous acids and bases. Most studies use methanol for the transesterification, and few studies have investigated the transesterification of microalgal oil using ethanol. Beyond the environmental benefits of microalgae compared to plant-based biomass, replacing methanol with bioethanol is advantageous due to its lower cost and reduced toxicity. If the emulsion issue between the produced biodiesel and ethanol is resolved, ethanol could be a more environmentally friendly alternative for green fuel production. This study evaluated various metal oxides as catalysts for the transesterification of rapeseed oil using ethanol as both reagent and solvent to improve miscibility. From catalyst screening, CaO showed the highest fatty acid ethyl esters yield and this catalyst was then tested at different reaction times in two systems (round-bottom flask and autoclave reactor) for the transesterification of both rapeseed and microalgal (Scenedesmus sp.) oil. The highest reaction yield was 86.0% for rapeseed oil and 81.3% for microalgal oil using 114:1 ethanol: oil molar ratio with CaO in an autoclave reactor. This work addresses the limited studies on ethanol in microalgal oil transesterification, demonstrating the effectiveness of CaO as a catalyst. It highlights the potential of ethanol as a greener, cost-effective alternative to methanol for biodiesel production.Graphical

Ultrafast humidity sensor and transient humidity detections in high dynamic environments

Limited by the adsorption and diffusion rate of water molecules, traditional humidity sensors, such as those based on polymer electrolytes, porous ceramics, and metal oxides, typically have long response times, which hinder their application in monitoring transient humidity changes. Here we present an ultrafast humidity sensor with a millisecond-level response. The sensor is prepared by assembling monolayer graphene oxide quantum dots on silica microspheres using a simple electrostatic self-assembly technique. Benefiting from the joint action of the micro spheres and the ultrathin humidity-sensitive film, it displays the fastest response time (2.76 ms) and recovery time (12.4 ms) among electronic humidity sensors. With the ultrafast response of the sensor, we revealed the correlation between humidity changes in speech airflow and speech activities, demonstrated the noise immunity of humidity speech activity detection, confirmed the humidity shock caused by explosions, realized ultrahigh frequency respiratory monitoring, and verified the effect of humidity-triggering in the non-invasive ventilator. This ultrafast humidity sensor has broad application prospects in monitoring transient humidity changes.

Effectiveness of an E-Nose Based on Metal Oxide Semiconductor Sensors for Coffee Quality Assessment

Effectiveness of an E-Nose Based on Metal Oxide Semiconductor Sensors for Coffee Quality Assessment

Operando Unveiling of Hydrogen Spillover Mechanisms on Tungsten Oxide Surfaces.

Hydrogen spillover is an important process in catalytic hydrogenation reactions, facilitating H2 activation and modulating surface chemistry of reducible oxide catalysts. This study focuses on the operando unveiling of platinum-induced hydrogen spillover on monoclinic tungsten trioxide (γ-WO3), employing ambient pressure X-ray photoelectron spectroscopy, density functional theory calculations and microkinetic modeling to investigate the dynamic evolution of surface states at varied temperatures. At room temperature, hydrogen spillover results in the formation of W5+ and hydrogen intermediates (hydroxyl species and adsorbed water), facilitated by Pt metal clusters. With increasing temperature, water desorption, reverse hydrogen spillover and surface-to-bulk diffusion of hydrogen atoms compete with each other, leading initially to reoxidation and then further reduction of W atoms in the near-surface. The combined experimental results and simulations provide a comprehensive understanding of the mechanisms underlying hydrogen interaction with reducible metal oxides, lending insights of relevance to the design of enhanced hydrogenation catalysts.

Hydrogen Sensing via Heterolytic H2 Activation at Room Temperature by Atomic Layer Deposited Ceria.

Ultrathin atomic layer deposited ceria films (< 20 nm) are capable of H2 heterolytic activation at room temperature, undergoing a significant reduction regardless of the absolute pressure, as measured under in-situ conditions by near ambient pressure X-ray photoelectron spectroscopy. ALD-ceria can gradually reduce as a function of H2 concentration under H2/O2 environments, especially for diluted mixtures below 10%. At room temperature, this reduction is limited to the surface region, where the hydroxylation of the ceria surface induces a charge transfer towards the ceria matrix, reducing Ce4+ cations to Ce3+. Thus, ALD-ceria replicates the expected sensing mechanism of metal oxides at low temperatures without using any noble metal decorating the oxide surface to enhance H2 dissociation. The intrinsic defects of the ALD deposit seem to play a crucial role since the post-annealing process capable of healing these defects leads to decreased film reactivity. The sensing behavior was successfully demonstrated in sensor test structures by resistance changes towards low concentrations of H2 at low operating temperatures without using noble metals. These promising results call for combining ALD-ceria with more conductive metal oxides, taking advantage of the charge transfer at the interface and thus modifying the depletion layer formed at the heterojunction.

Improving the Selectivity of Metal Oxide Semiconductor Sensors for Mustard Gas Simulant 2-Chloroethyl Ethyl Sulfide by Combining the Laminated Structure and Temperature Dynamic Modulation.

Insufficient selectivity is a major constraint to the further development of metal oxide semiconductor (MOS) sensors for chemical warfare agents, and this paper proposed an improved scheme combining catalytic layer/gas-sensitive layer laminated structure with temperature dynamic modulation for the Mustard gas (HD) MOS sensor. Mustard gas simulant 2-Chloroethyl ethyl sulfide (2-CEES) was used as the target gas, (Pt + Pd + Rh)@Al2O3 as the catalytic layer material, (Pt + Rh)@WO3 as the gas-sensitive layer material, the (Pt + Pd + Rh)@Al2O3/(Pt + Rh)@WO3 sensor was prepared, and the sensor was tested for 2-CEES and 12 battlefield environment simulation gases under temperature dynamic modulation. The results showed that the sensor only showed obvious characteristic peaks in the resistance response curves to HD under certain conditions (100-400 °C, the highest temperature was held for 1 s and the lowest temperature was held for 2 s), and its peak height reached 6.12, which was far higher than other gases, thus realizing the high selectivity of the MOS sensor to 2-CEES. Meanwhile, the sensor also showed good sensitivity, detection limits, response/recovery times, anti-interference, and stability, which further verified the feasibility of the improved scheme.

Non-Enzymatic Electrochemical Glucose Sensors Based on Metal Oxides and Sulfides: Recent Progress and Perspectives

With the sudden advancement of glucose biosensors for monitoring blood glucose levels for the prevention and diagnosis of diabetes, non-enzymatic glucose sensors have aroused great interest owing to their sensitivity, stability, and economy. Recently, researchers have dedicated themselves to developing non-enzymatic electrochemical glucose sensors for the rapid, convenient, and sensitive determination of glucose. However, it is desirable to explore economic and effective nanomaterials with a high non-enzymatic catalysis performance toward glucose to modify electrodes. Metal oxides (MOs) and metal sulfides (MSs) have attracted extensive interest among scholars owing to their excellent catalytic activity, good biocompatibility, low cost, simple synthesis process, and controllable morphology and structure. Nonetheless, the exploitation of MOs and MSs in non-enzymatic electrochemical glucose sensors still suffers from relatively low conductivity and biocompatibility. Therefore, it is of significance to integrate MOs and MSs with metal/carbon/conducive polymers to modify electrodes for compensating the aforementioned deficiency. This review introduces the recent developments in non-enzymatic electrochemical glucose sensors based on MOs and MSs, focusing on their preparation methods and how their structural composition influences sensing performance. Finally, this review discusses the prospects and challenges of non-enzymatic electrochemical glucose sensors.

Recent Advances in Surface Functionalized 3D Electrocatalyst for Water Splitting

Hydrogen is gaining attention as a fossil fuel alternative due to its potential to meet global energy demands. Producing hydrogen from water splitting is promising as a clean and sustainable fuel pathway. The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are crucial in electrocatalytic water splitting for energy conversion and storage. However, water electrolysis faces challenges in cost, efficiency, and scalability. Alternative transition metal electrocatalysts and emerging 2D materials advance electrolysis research, though transitioning from academia to industry remains challenging. The introduction of 3D‐printing technologies has revolutionized electrode fabrication for HER and OER. This review explores integrating 3D‐printing technologies and surface functionalization with non‐noble metal‐based electrocatalysts and emerging 2D materials. It focuses on surface‐functionalized 3D‐printed electrodes using technologies like selective laser melting, stereolithography, and fused deposition modeling with non‐noble metal electrocatalysts such as transition metal oxides, hydroxides, and emerging 2D materials like transition metal carbide/nitride (MXenes) and transition metal dichalcogenides (TMDCs). The review highlights the opportunities and challenges in scalable fabrication, long‐term durability, and cost‐efficiency for practical implementation. Future research directions include exploring new materials for 3D printing and alternative electrocatalysts alongside leveraging theoretical and machine‐learning approaches to accelerate the development of competitive materials for water electrolysis.

High-Performance Hydrogen Sensing at Room Temperature via Nb-Doped Titanium Oxide Thin Films Fabricated by Micro-Arc Oxidation.

Metal oxide semiconductor (MOS) hydrogen sensors offer advantages, such as high sensitivity and fast response, but their challenges remain in achieving low-cost fabrication and stable operation at room temperature. This study investigates Nb-doped TiO2 (NTO) thin films prepared via a one-step micro-arc oxidation (MAO) with the addition of Nb2O5 nanoparticles into the electrolyte for room-temperature hydrogen sensing. The characterization results revealed that the incorporation of Nb2O5 altered the film's morphology and phase composition, increasing the Nb content and forming a homogeneous composite thin film. Hydrogen sensing tests demonstrated that the NTO samples exhibited significantly improved sensitivity, selectivity, and stability compared to undoped TiO2. Among the fabricated samples, NTO thin film prepared at Nb2O5 concentration of 6 g/L (NTO-6) showed the best performance, with a broad detection range, excellent sensitivity, rapid response, and good specificity to hydrogen. A strong linear relationship between response values and hydrogen concentration (10-1000 ppm) highlights its potential for precise hydrogen detection. The enhanced hydrogen sensing mechanism of NTO thin films primarily stems from the influence of Nb2O5; nanoparticles doping in the anatase-phase TiO2 structure on the semiconductor surface depletion layer, as well as the improved charge transfer and additional adsorption sites provided by the Nb/Ti composite metal oxides, such as TiNb2O7 and Ti0.95Nb0.95O4. This study demonstrates the potential of MAO-fabricated Nb-doped TiO2 thin films as efficient and reliable hydrogen sensors operating at room temperature, offering a pathway for novel gas-sensing technologies to support clean energy applications.

QD/SnO2 Photoactivated Chemoresistive Sensor for Selective Detection of Primary Alcohols at Room Temperature

Sensors based on nanocomposites of quantum dots (QDs) and wide-gap metal oxides are of exceptional interest for photoactivated detection of toxic and pollutant gases without thermal heating. However, the class of detecting gases has been limited almost exclusively to oxidizing gases like NO2. Here, we designed a photoactivated sensor for the selective detection of primary alcohols at room temperature using CdSe quantum dots coupled to a wide-gap SnO2 semiconductor matrix. Our concept of the sensor operations is based on the photochemical reaction of primary alcohols via photoactivated QD-SnO2 charge transfer and does not involve chemisorbed oxygen, which is traditional for the operation of metal oxide sensors. We demonstrated an efficient sensor response to C1–C4 primary alcohols of ppm concentration under photoexcitation with a yellow LED in the absence of a signal from other volatile organic compounds (VOCs). We believe that proposed sensor concept opens up new ways to design photoactivated sensors without heating for the detection of VOCs.

Applications of Nanomaterial Coatings in Solid-Phase Microextraction (SPME)

This review explores the advances in developing adsorbent materials for solid-phase microextraction (SPME), focusing on nanoparticles, nanocomposites, and nanoporous structures. Nanoparticles, including those of metals (e.g., gold, silver), metal oxides (e.g., TiO2, ZnO), and carbon-based materials (e.g., carbon nanotubes, graphene), offer enhanced surface area, improved extraction efficiency, and increased selectivity compared to traditional coatings. Nanocomposites, such as those combining metal oxides with polymers or carbon-based materials, exhibit synergistic properties, further improving extraction performance. Nanoporous materials, including metal–organic frameworks (MOFs) and ordered mesoporous carbons, provide high surface area and tunable pore structures, enabling selective adsorption of analytes. These advanced materials have been successfully applied to various analytes, including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), pesticides, and heavy metals, demonstrating improved sensitivity, selectivity, and reproducibility compared to conventional SPME fibers. The incorporation of nanomaterials has significantly expanded the scope and applicability of SPME, enabling the analysis of trace-level analytes in complex matrices. This review highlights the significant potential of nanomaterials in revolutionizing SPME technology, offering new possibilities for sensitive and selective analysis in environmental monitoring, food safety, and other critical applications.

Electrochromism via reversible electrodeposition of solid iodine

Electrochromic materials were discovered in the 1960s when scientists observed reversible changes between the light and dark states in WO3 thin films under different voltages. Since then, researchers have identified various electrochromic material systems, including transition metal oxides, polymer materials, and small molecules. However, the electrochromic phenomenon has rarely been observed in non-metallic elemental substances. Herein, we propose the development of non-metallic iodine electrodeposition-based electrochromic dynamic windows using a water-in-salt electrolyte containing iodine ions. The unique electrolyte environment and solvation structure of the water-in-salt electrolyte suppress the dissolution and shuttle effect of iodine, thereby achieving a different reaction pathway compared to traditional electrolytes. This pathway involves a reversible solid-liquid transition between solid iodine and solvated iodide ions. The iodine electrodeposition-based electrochromic dynamic window demonstrates a high optical contrast of 76.0% with near colour neutrality and excellent cycling stability. A practical 400 cm2 complementary dynamic window is fabricated to demonstrate good electrochromic performance, including high optical contrast, a near colour-neutral opaque state, fast response time, uniform modulation, and polarity-switchable functionality.

Electroreduction-Driven Formation and Connectivity of Polyoxometalate Coordination Networks.

We present the synthesis of metal oxide coordination networks based on Preyssler-type polyoxoanions ([NaP5W30O110]14- and [NaP5MoW29O110]14-) bridged with metal-aquo complexes ([M(H2O)n]m+, Mm+ = Co2+, Ni2+, Zn2+, Y3+), induced by electrochemical reduction. Networks bridged with first-row transition metals are isostructural with a previously reported Co-bridged structure, while the Y3+-bridged structure is new. All networks feature an uncommon binding motif of the metal cation to the oxygen atoms at cap positions, which we hypothesize is due to increased electron density at the cap upon reduction. Oxidation of a Zn2+-bridged network resulted in a new structure in which Zn2+-Ocap bonds are lost, indicating the importance of reduction in the connectivity of these polyoxometalate-based coordination networks.