Specific Surface Area Activity Research Articles

Self-healing Micro-Supercapacitor Based on Robust Liquid Metal-CNT-PEDOT:PSS Film for Wireless Powering of Integrated Strain Sensor.

The limited energy density of micro-supercapacitors (MSCs) and challenges in their integration significantly impede the advancement of MSCs in wearable electronic devices. Here, this work designs a robust and wrinkled liquid metal-CNT-PEDOT:PSS film with high capacity and self-healing properties (defined as LM-CNT-PEDOT:PSS). The wrinkled structure further enhances tensile properties of LM-CNT-PEDOT:PSS and increases its active specific surface area per unit. Simultaneously, the incorporation of liquid metal (LM) enhances both the mechanical and healing properties of the LM-CNT-PEDOT:PSS electrode. The flexible and self-healing MSC based on wrinkled LM-CNT-PEDOT:PSS shows a remarkable specific capacitance of 114.29 mF cm-2 and a high areal energy density of 15.47 µW h cm-2. Furthermore, the electrochemical performance of the healed MSC retained 90.01% of its initial performance, and the MSC unit can be arbitrarily integrated according to various energy and voltage requirements through the healing properties of LM-CNT-PEDOT:PSS, widening the range of applications in next-generation microelectronic devices. The wrinkled LM-CNT-PEDOT:PSS film is utilized for the fabrication of a highly sensitive strain sensor. Simultaneously, the prepared sensor can be seamlessly integrated with wireless charging and MSC to facilitate convenient monitoring of physiological signals, thereby offering an effective solution for the advancement of wearable technology and self-powered systems.

“Nanoregion” effect of ionic liquid mixture system for preparing highly active porous electrocatalytic hydrogen production materials

The development of porous electrocatalytic materials with high activity and large specific surface area is the key to realizing efficient hydrogen production by water electrolysis. In this paper, a universial strategy for preparing porous non-precious metal electrocatalysts with high effective surface area is provided based on the “nanoregion” formed by ionic liquid mixture system, and the feasibility is verified by constructing a porous NiCo@NC based electrocatalyst. The microstructure, surface composition, specific surface area and electrochemical properties of the porous electrocatalyst are investigated systematically. Compared with the traditional hydrothermal synthesis, the “nanoregion” effect can give the NiCo@NC electrocatalyst rich pore structure and good hydrophilicity, thus effectively improve the effective surface area available for the electrochemical reaction. As a result, the overpotential for HER on NiCo@NC-500 prepared in the ionic liquid mixing system is 113 mV lower than that on NiCo@NC-500-w prepared by common hydrothermal process, and the Tafel slope decreases by 37 mV dec−1 (33.9 %), further verifying the effectiveness of this simple and green strategy to develop porous non-precious metal electrocatalysts for hydrogen production by the “nanoregion” effect of ionic liquid mixture system.

Collard-like Bi2S3@Au nanocomposites-based label free electrochemical immunosensor for quantitative detection of CA19-9

Here, a label-free immunosensor was conducted using rGO/Collard-like Bi2S3@Au nanocomposite system to detect carbohydrate antigen 19-9 (CA19-9) as a diagnostic biomarker for Pancreatic cancer. The unique morphology of Collard-like Bi2S3 increases its specific surface area, which allows it to immobilize more materials and biomolecules on its surface. To realize the covalent bonding of bismuth-based materials with biomolecules, bismuth-based materials were functionalized by Au NPs. Besides, the superior electrochemical activity and large specific surface area of Bi2S3@Au improved the stability of the sensor, which made it an ideal candidate for regulating the sensing interface in this study. Meanwhile, reduced graphene oxide (rGO) with remarkable electrical conductivity to improve the current response of the sensing interface, thus broadening the linear range of the immunosensor. Based on the above materials, a label free electrochemical immunosensor was constructed for detecting CA19-9. Under optimal conditions, it displays good linear relationship within the range of 0.01 U mL-1 to 100 U mL-1, the detection limit being 0.0012 U mL-1. Additionally, the immunosensor prepared in this work is characterized by superior interference immunity, reproducibility and storage stability, and has yielded satisfactory recovery rate in testing the serum samples of patients.

A multi-modal sensor based on LRH/MnO2 for the detection of glutathione and anthrax biomarkers

A novel multi-modal and multi-detector nanoprobe was constructed. 7HC-LEuH was prepared by co-intercalating 7-hydroxycoumarin (7HC) with 1-octanesulfonate (OS) into layered europium hydroxide (LEuH), which was subsequently assembled with MnO2 by electrostatic self-assembly to obtain 7HC-LEuH/MnO2 nanoprobe. Wherein MnO2 can dynamically quench the fluorescence of 7HC-LEuH by FRET. The synthesized material has the advantages of oxidase-like activity and large specific surface area of MnO2, as well as the fluorescence property of 7HC-LEuH, which provides more possibilities for the detection of biomolecules. The nanoprobe can realize the fluorescence/colorimetric detection of glutathione (GSH) (linear range of 5–35 μM / 1–5 μM and detection limit of 15.4 nM / 14.6 nM, respectively), and the fluorescence/visualization detection of 2,6-Pyridinedicarboxylic acid (DPA) (linear range of 5–90 μM / 20–200 μM and detection limit of 9.9 nM / 1.7 μM, respectively). The multi-modal detection improves the accuracy, and the multi-detector improves the comprehensiveness of the analytical detection, which provides a new idea for further research on multifunctional sensors.

Assembly and operation optimization of proton exchange membrane water electrolyzer for performance enhancement

Abstract Proton exchange membrane water electrolysis (PEMWE) for hydrogen production possesses wide-ranging and rapid dynamic response capabilities, offering promising applications in the consumption of new energy sources and the dynamic balancing of power grids with a high proportion of renewable energy. The assembly and operating conditions of PEMWE significantly affect its performance. Therefore, thoroughly studying and understanding the influence of PEMWE’s assembly and operating conditions on water electrolysis performance are crucial for enhancing PEMWE’s performance and promoting its applications. In this research, the influence of installation preload torque, feedwater flow rate, and operating temperature on the performance of the electrolyzer, including the electrochemical active specific surface area (ECSA), high-frequency resistance (HFR) and various types of polarizations (including activation polarization, ohmic polarization, and mass transfer polarization) during the operation of the electrolyzer, were detailedly investigated. The results showed that the optimal preload torque and operating temperature for the electrolyzer were 3 Nm and 80°C. Under these conditions, an optimized PEMWE performance would be achieved by ensuring that the feedwater flow rate exceeded the water consumption during electrolysis.

XCT images-based modeling for elucidating electrochemical inert phase-dependent multiscale electrode kinetic behaviors

The electrochemically inert phase (EIP) within the electrode is formed by the combination of carbon black and binder, characterized by a highly heterogeneous spatial distribution and structural morphology. This heterogeneity impairs electrode performance under varying discharge rates and temperatures. In this study, X-ray computed tomography is employed to image the original electrode. The resulting grayscale images are digitally processed to reveal the two-dimensional (2D) and three-dimensional (3D) features of the EIP morphology, thereby providing a design window to understand the influence of EIP morphology. The physical structure characterization indicates that, compared to bulk-like EIP (B-EIP), film-like EIP (F-EIP) tends to cover the active surface of the active material (AM), exacerbating the heterogeneity of the lithiation reactions within the electrode. The reduction in the AM active surface area correlates the state of lithiation (SOL) of particles with their active specific surface area (αa). At low temperatures, the temperature sensitivity of electrodes intensifies the risk of αa loss, promoting heterogeneous reaction transfer between particles. The Biot number (Bi) is used to evaluate the competing mechanisms between interfacial reactions and bulk diffusion within particles. In electrodes with a high EIP content, the reaction rate at the particle/electrolyte interface is accelerated, causing particle performance to be dominated by interfacial reactions. Finally, the electrochemistry and heat generation from the particle-level to the electrode-level in thicker electrodes are examined. It demonstrates that ion diffusion in the pore controls interfacial reactions and heat transport behavior. Aggregated high-flux reactions and localized hot spots exacerbate the heterogeneous degradation and side reactions within the electrode.

Performance evaluation of a dynamic electrooxidation systems with magnetically functionalised UiO-66-NH2 and Ti/Sb–SnO2 for methotrexate treatment

Novel conductive MOF magnetic particles Fe3O4@UiO-66-NH2@PANI (FUP) were prepared and combined with Ti/Sb–SnO2 electrodes to construct a dynamic system with improved electrochemical oxidation efficiency. Electrochemical tests revealed that the Ti/Sb–SnO2–FUP electrodes showed a high active specific surface area and low charge transfer resistance. Investigation of the effects of parameters such as dynamic particle loading, magnetic separation time, initial concentration, Na2SO4 dosage and solution pH on the methotrexate (MTX) degradation rate revealed that the degradation rate reached 97.5%. Electron paramagnetic resonance spectroscopy revealed that the Ti/Sb–SnO2–FUP electrodes could produce abundant hydroxyl radicals, possibly due to the unique pore structure of UiO-66-NH2 and the semiconductor structure of aniline. Finally, the decomposition pathway of MTX and ecotoxicity of the intermediates were analysed through LC-MS/MS and Toxicity Estimation Software Tool theoretical calculations combined with genotoxicity experiments. The results showed that Ti/Sb–SnO2–FUP could effectively reduce the toxicity of the intermediates. In this work, a dynamic electrooxidation system was developed using magnetic Ti/Sb–SnO2 electrodes coupled with MOFs, providing a new idea to improve the oxidative degradation efficiency of electrooxidation systems.

Oxygen-Controlled Electrocatalysis for Selective Dechlorination of 2-Chloro-5-Trichloromethyl Pyridine on Activated Ag Electrode

Electrochemical selective dechlorination can be regarded as one of the most promising strategies for generating high-valued chemicals. In the electrochemical dechlorination process of 2-chloro-5-trichloromethylpyridine (TCMP), except the anticipated dechlorination products involving 2-chloro-5-dichloromethylpyridine (DCMP), 2-chloro-5-chloromethylpyridine (CCMP), and 2-chloro-5-methylpyridine (CMP), some unexpected oxygen-incorporated products (6-chloronicotinic acid (CNA) and 6-chloronicotinoyl methyl ester (MCN)) can be obtained. Consequently, understanding the electrochemical dechlorination behavior of TCMP is crucial. Our research revealed that the activated Ag electrodes in halide ion solution exhibit enhanced electrochemical activities for electrochemical dechlorination of TCMP, compared with the pure Ag owing to the increased active specific surface areas and charge transfer. Second, oxygen participation in the reaction is a necessary condition for the formation of oxygen-incorporated products. A 100% selectivity of oxygen-incorporated products can be obtained at the potential of −0.6 V vs Ag/AgCl. Conversely, insufficient oxygen may lead to the potential becoming the determining condition that affects the reaction pathways. A more negative potential (−1.2 V vs Ag/AgCl) is conducive to the formation of dechlorination products with 94.2% conversion and 100% selectivity. This study, for the first time, elucidates the electrocatalyst, atmosphere, and potential-dependent activity and selectivity for the two dechlorination pathways of TCMP.

Ce-doped cobalt-based hydroxide assisted with low-temperature molten salt for industrial oxygen evolution reaction

Developing low cost and high-performance oxygen evolution electrocatalysts is significant to improve the efficiency of water electrolysis for large-scale hydrogen production. Cobalt hydroxide is a promising electrocatalyst for oxygen evolution reaction (OER), but its poor conductivity and activity seriously restrict the practical application. A simple one-step low temperature molten salt method was applied to successfully synthesize the Ce-doped cobalt hydroxide nitrate (Ce-CoNH/CF), which exhibits outstanding OER performance with a low overpotential of 448 mV at the current density of 1000 mA/cm2 in 1 mol/L KOH. The remarkable performance of Ce-CoNH/CF electrode in OER may be the comprehensive result of fast reaction kinetics, large electrochemical active specific surface area (ECSA) and small charge transfer resistance (Rct) as revealed by the Tafel, cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) analysis. Under the simulated industrial test conditions (6 mol/L KOH, 70 °C), the Ce-CoNH/CF electrode still displays excellent OER performance.

NiFeP nanosheet arrays supported on nickel nitrogen codoped carbon nanofiber as an efficient bifunctional catalyst for overall water splitting

Transition metal phosphides have emerged as effective electrocatalysts for water splitting. In this study, novel NiFeP nanosheet arrays supported on nickel nitrogen codoped carbon nanofiber (NiFeP@Ni-NCNF) was synthesized through a combination of electrospun, template-directed growth, and phosphorization strategy. The utilization of Ni-NCNF as a substrate for constructing the nanoarrays structure with superhydrophilic and superaerophobic properties significantly enhances the electrochemical active specific surface area of the electrocatalytic material. The synergistic effect of Ni2P and Fe2P and the excellent conductivity of the Ni-NCNF substrate promote NiFeP@Ni-NCNF to exhibit excellent HER/OER electrocatalytic properties. The NiFeP@Ni-NCNF exhibits low overpotentials of 131 mV and 204 mV for HER and OER at 10 mA cm−2, respectively. Additionally, using NiFeP@Ni-NCNF as the anode and cathode of the electrolytic water device displays a voltage of 1.61 V at 10 mA cm−2, and the Faraday efficiency of the two electrodes is near 100 %. This research presents an extensible and cost-effective strategy for synthesizing phosphide-based catalysts with unique nanostructures and desirable water splitting catalytic properties.

Eco-friendly and large-scale fabrication of NiMoN/Ni(OH)2/NF as highly efficient and stable alkaline hydrogen evolution reaction electrode

Bimetallic nickel-molybdenum nitride (NiMoN) catalysts have attracted great attention due to their remarkable similarity to group VIII noble metals in terms of electronic structure, good electron conductivity, and durability for the hydrogen evolution reaction (HER). However, the existing approaches for fabricating NiMoN catalysts usually entail a series of multiple steps and hazardous ammoniated ingredient. As a result, these methods are difficult to be scaled up for large-area fabrication towards industrial water splitting. Herein, a hierarchical composite NiMoN@Ni(OH)2@NF composite electrode with a sheet morphology was synthesized based on a rational combination of seawater etching and magnetron sputtering. This method is easily scalable for producing large-area electrodes with minimal pollution. The incorporation of Ni(OH)2@NF nanoarray carriers enhances the exposure of additional active sites on the NiMoN layer, thereby augmenting the electrochemically active specific surface area of the electrode.The as-synthesized NiMoN@Ni(OH)2@NF electrode demonstrates excellent HER activity, with an overpotential of 57 mV at 10 mA cm−2, and exhibits remarkable long-term catalytic stability for over 100 h at a current density of 100 mA cm−2.This study presents an eco-friendly and straightforward method for preparing large-scale transition metal nitride catalysts with high catalytic activity.

Engineering of interfacial electric field by g-C3N4/ZnSnO3 heterojunction for excellent photocatalytic applications

The heterojunction of 2D g-C3N4 thin nanosheets and double-shelled ZnSnO3 nanocubes was prepared via a reliable, convenient, and cost-effective technique to achieve efficient photocatalytic activity. The unique double-layered structure of ZnSnO3 helps to absorb more visible light and provides a shorter diffusion path for charge carriers. The integration of some wrapped g-C3N4 nanosheets to the outer layer of ZnSnO3 increases the multiple active sites and specific surface area (SBET) to boost the photocatalytic reaction. The synergistic effect of heterojunction and oxygen vacancies effectively stimulates the generation and spatial charge separation. Furthermore, as-synthesized 2D/3D heterostructure develops an interfacial electric field that plays an efficient role in charge migration and enhances the redox ability of the material. The degradation efficiency for MB (99.5 %, within 30 mins), TC (98.2 %, within 120 mins), H2 production rate (1799 μmol g−1 h−1) and CO evolution rate (23.6 μmol g−1 h−1) confirms the excellent performance of multifunctional photocatalyst. Additionally, DFT calculations of electronic band structure and density of states are in excellent agreement with experimental results. This work highlights the new perspective on designing suitable nanostructures for photocatalytic applications.

Co/CoP@NC heterostructures as bifunctional catalysts to enhance the alkaline water splitting

The development of efficient and stable non-precious bifunctional electrocatalysts is of great significance, but it remains a great challenge. Herein, we have constructed Co/CoP@NC heterojunction catalyst loaded with Co and CoP particles on a nitrogen-doped carbon (NC) substrate using the pyrolysis-oxidation-phosphating strategy. The synergistic effect of Co and CoP particles on the NC substrate increases the active specific surface area, accelerates the charge transfer rate, and improves the intrinsic activities of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). The Co/CoP@NC catalyst exhibits superior HER and OER performance. Specifically, the overpotentials required for Co/CoP@NC to reach the current density of 10 mA cm−2 are 142 and 186 mV for HER and OER, respectively. This study provides new insights into the design and synthesis of efficient and stable Co-based heterostructure catalysts.

Prevention of morphological change for (Ba,Sr)(Co,Fe)O3 cathodes by incorporating (Ce,Gd)O2 for intermediate-temperature solid oxide fuel cells

Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) generally exhibits superior cathode activity compared to La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) for intermediate-temperature solid oxide fuel cells (IT-SOFCs). However, the chemical stability of BSCF is inferior to that of LSCF. When BSCF cathodes are sintered at a high temperature of 1050 °C, performance was compromised due to the formation of (Ba,Sr)ZrO3 between the scandia-stabilized zirconia (ScSZ) electrolyte and gadolinia-doped ceria (GDC) interlayer. The oxide ionic conductivity of (Ba,Sr)ZrO3 was low, decreasing the cathode performance. Furthermore, the BSCF grains enlarged, and cobalt oxide formed due to BSCF decomposition, decreasing the active specific surface area. However, by incorporating GDC into the BSCF cathode, the morphology remained unchanged and cobalt oxide formation was prevented, despite (Ba,Sr)ZrO3 still forming. The performance of the cell with the BSCF-GDC composite cathode surpassed that with the BSCF cathode due to decreased polarization resistance attributed to the oxygen surface exchange and diffusion processes in the cathode.

MoO3/V2O5/Ni(OH)2 with multiple heterojunction interfaces for the hydrogen preparation from urea-containing wastewater

Compared to a single heterostructure, constructing multiple heterojunction interfaces to enhance bifunctional catalytic activity still faces challenges. Herein, a nanoflower-like electrocatalyst with multiple heterojunction interfaces, which consists of MoO3, V2O5, and Ni(OH)2 in-situ grown on nickel foam, is prepared through a one-step hydrothermal method (MoO3/V2O5/Ni(OH)2/NF, named MVN/NF). The MVN/NF exhibits superior catalytic performance, attributable to enhanced electron transfer facilitated by numerous heterojunction interfaces, a substantial active specific surface area, and a self-supported architecture. It requires low potentials for hydrogen evolution reaction, urea oxidation reaction, and overall urea electrolysis of 81 mV, 1.351 V, and 1.450 V (vs. RHE), respectively, to reach a current density of 10 mA cm-2. By cutting the material into a large-scale electrode for use in an alkaline electrolyzer, its Faraday efficiency was 90.0%, and the urea decomposition rate reached 45.1%. This work offers broad application prospects for the realization of large-scale hydrogen production and the decomposition of urea-containing wastewater.

Controlled growth of a graphdiyne/cobalt hydroxide heterointerface for efficient chlorine production

The chlor-alkali process plays a key and irreplaceable role in the chemical industry because of its use in various industrial processes. However, the low selectivity and efficiency of the reported chlorine evolution reaction (CER) electrocatalysts obviously hinder its practical use. We report a simple method for the controlled growth of high-performance CER electrocatalysts by first growing cobalt hydroxide on the surface of carbon cloth, followed by the in-situ growth of graphdiyne (GDY/Co(OH)2). As expected, the as-synthesized catalyst has a small overpotential of only 83 mV at 10 mA cm−2, a maximum Faradaic Efficiency (FE) of 91.54%, and a high chlorine yield of 157.11 mg h−1 cm−2 in acidic simulated seawater. Experimental results demonstrate that the in-situ growth of GDY on the Co(OH)2 surface leads to the formation of heterointerfaces with strong electron transfer between GDY and Co atoms, resulting in a higher conductivity, larger active specific surface area and more active sites, thereby improving the overall electrocatalytic selectivity and efficiency.

WITHDRAWN: Magnetic field-assisted electrodeposition of ZnCo2O4-rGo nanoelectrodes for enhanced supercapacitor performance

To investigate a convenient, rapid, and environmentally friendly method for the preparation of supercapacitor electrode materials to enhance supercapacitor performance, this study achieved the successful synthesis of ZnCo2O4-rGo (ZCG) nanomaterial electrodes on a nickel foam substrate. These electrodes were then assembled into supercapacitors using Magnetic field-assisted Electrodeposition (MFAED) technology. The surface morphology and structure characterization analysis revealed that the ZCG-4 material exhibited a mesoporous layered nanosheet structure. Moreover, they exhibited a significant specific active surface area of 155.7 m2/g and showed excellent adhesion to the nickel foam substrate. The electrochemical properties of the ZCG nanoelectrode material were studied in a 1 M KOH aqueous solution. The results revealed that the ZCG-4 nanoelectrode displayed low electrochemical impedance (Rs 0.23 Ω, Rct 1.36 Ω, and Zw 0.99 Ω) and a high specific capacitance of 2672 Fg−1. Furthermore, at a current density of 3 Ag−1, the electrode maintained good capacity retention (2672 Fg−1–2529 Fg−1, 94.6 %). Moreover, it retained a significantly high specific capacitance of 1339 Fg−1 even after 6000 cycles under a current density of 20 Ag−1. The supercapacitor assembled with ZCG-4 electrodes exhibits good electrochemical performance, possessing a high capacitance of 5.8F/cm2 at a current density of 1 mA/cm2. Moreover, the ZCG-4 supercapacitor demonstrates outstanding cyclic performance, maintaining 86 % capacity retention following 6000 charge–discharge cycles at a high current density of 30 mA/cm2. The mechanism of magnetic field electrodeposition for preparing ZCG has also been explained using magnetohydrodynamics theory. At a magnetic field strength of 6 T, the ion migration speed is 1.7 × 10−5 m/s, and the addition of the magnetic field effectively increases this speed. An effective magnetic field electrodeposition approach was thus proposed in this investigation to enable the synthesis of high-performance electrode materials and capacitors by combining metal oxide and rGo.

Oxygen-Deficient FeNbO4-x In-Situ Growth in Honey-Derived N-Doping Porous Carbon for Overall Water Splitting.

It is still a great challenge to reasonably design green, low cost, high activity and good stability catalysts for overall water splitting (OWS). Here, we introduce a novel catalyst with ferric niobate (FeNbO4) in-situ growing in honey-derived porous carbon of high specific surface area, and its catalytic activity is further enhanced by micro-regulation (oxygen vacancy and N-doping). From the experimental results and density functional theory (DFT) calculations, the oxygen vacancy in catalyst FeNbO4-x@NC regulates the local charge density of active site, thus increasing conductivity and optimizing hydrogen/oxygen species adsorption energy. FeNbO4 in-situ grows within N-doping honey-derived porous carbon, which can enhance active specific surface area exposure, strengthen gaseous substances escape rate, and accelerate electrons/ions transfer and electrolytes diffusion. Moreover, in-situ Raman also confirms O-species generation in oxygen evolution reaction (OER). As a result, the catalyst FeNbO4-x@NC shows good electrochemical performance in OER, HER and OWS.

Ultrathin Sulfur‐Doped g‐C3N4 Nanosheets Controlled by Steam Activation for Enhanced Visible‐Light Photocatalytic Performance

AbstractGraphite carbon nitride (g‐C3N4) has garnered considerable attention due to its excellent photocatalytic properties for the degradation of organic matter in wastewater treatment. Herein, sulfur‐doped g‐C3N4 nanosheets (CN−S‐X) were successfully synthesized via physical steam activation using thiourea and urea as precursors. Comprehensive characterizations demonstrate that the enhanced photocatalysis is attributed to the ultrathin structure, highly active site, vacancy defects, and high specific surface area due to the synergy of S doping and steam activation. The as‐prepared CN−S‐25 photocatalyst exhibits a desirable degradation efficiency of 95.4 % for methylene blue dye with a high degradation rate of 2.65×10−2 min−1 under visible‐light irradiation, which are 2.1 and 5.52 times those for bulk g‐C3N4, respectively as well as good reusability and stability. This study provides a simple and promising strategy to regulate the nanostructure of g‐C3N4 for highly efficient photocatalytic degradation of organic pollutants.

Electrochromic Devices Based on 2D MoO3-x/PEDOT:PSS Composite Film with Boosted Ion Transport.

Electrochromic materials allow for optical modulation and have attracted much attention due to their bright future in applications such as smart windows and energy-saving displays. Two-dimensional (2D) molybdenum oxide nanoflakes with combined advantages of high active specific surface area and natural layered structure should be highly potential candidates for electrochromic devices. However, the efficient top-down preparation of 2D MoO3 nanoflakes is still a huge challenge and the sluggish ionic kinetics hinder its electrochromic performance. Herein, we demonstrated a feasible thiourea-assisted exfoliation procedure, which can not only increase the yield but also reduce the thickness of 2D MoO3-x nanoflakes down to a few nanometers. Furthermore, electrophoretic-deposited MoO3-x nanoflakes were combined with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-conjugated polymer to simultaneously enhance the ionic kinetics and electronic conductivity, with a diffusion coefficient of 3.09 × 10-10 cm2 s-1 and a charge transport resistance of 33.7 Ω. The prepared 2D MoO3-x/PEDOT:PSS composite films exhibit improved electrochromic performance, including fast switching speed (7 s for bleaching, 5 s for coloring), enhanced coloration efficiency (87.1 cm2 C-1), and large transmittance modulation (ΔT = 65%). This study shows outstanding potential for 2D MoO3-x nanoflakes in electrochromic applications and opens new avenues for optimizing the ion transport in inorganic-organic composites, which will be possibly inspired for other electrochemical devices.