High-resolution Electron Microscopy Studies Research Articles

Achieving the 1D Atomic Chain Limit in Van der Waals Crystals.

Experiments with graphene have demonstrated that 2D van der Waals materials can be stable, robust, and efficiently manipulated at the level of individual atomic planes. However, the stability and manipulation of 1D van der Waals materials and individual atomic chains remains elusive. Here, the ability to exfoliate and process two representative van der Waals materials containing 1D motifs, namely MoI3 and Ta2Se8I, at the scale of individual atomic chains is demonstrated. High-resolution transmission electron microscopy and atomic force microscopy studies confirm the presence of stable individual atomic chains of MoI3 at room temperature. It is further shown that 1D van der Waals materials with low exfoliation energy, such as Ta2Se8I, can be processed with electron beams to achieve suspended individual atomic chains. Ab initio calculations corroborate the findings regarding the cleavage energies and the thermodynamic stability of individual atomic chains in these 1D van der Waals materials. These results demonstrate that the top-down approach in material processing can be extended to the scale of individual chains.

Revealing the displacive and diffusional phase transformations in a low-modulus Ti-12Nb alloy

Non-toxic and biocompatible Ti alloys with low modulus are promising biomaterials for implants. Except from the intensely studied metastable β Ti-Nb-based alloys, the α′-type Ti alloys could also present low modulus. But due to the low β stability, the microstructures of these α′ Ti alloys are sensitive to the heat-treatments especially to the cooling rates, which could lead to very different deformation mechanisms and mechanical properties. Thus, the phase transformations and the ‘microstructure–mechanical property’ correlation in the α′ Ti alloys need to be established. In this study, a novel Ti-12Nb wt% alloy was prepared and cooled from the β region temperature to obtain the water-quenched (WQ), air-cooled (AC), and furnace-cooled (FC) samples. Systematic investigations revealed the displacive β → α′ martensitic transformation in the WQ and diffusional β → β + α transformation in the AC and FC samples, in which the α′/α show evident variant selections. The inter-variant orientation relationships (ORs) among the α′/α variants and their ORs with the retained β phase, were found to be agree well with the classical Burgers OR. The high-resolution transmission electron microscope (HRTEM) studies show coherent α′/α′ interfaces in the WQ samples and α/β phase boundaries in the AC and FC samples, the abnormal β nanodomains inside the α′ martensites in WQ samples and the ω nanoparticles in the β phase of AC and FC samples were also presented. The tensile tests show increasing Young's modulus of 61.8 GPa, 77.1 GPa and 108.6GPa in the WQ, AC and FC samples, respectively. The difference in the modulus of these samples was explained by the Nb dependency of Young's modulus in the Ti-Nb alloy. The correlations between the microstructures, deformation mechanisms and mechanical properties were established. The {101¯1}α′ and {101¯2}α′ deformation twins inside the α′ martensites are believed to contribute to the good plasticity in the WQ samples, while the fine α + β structures and severely piled-up dislocations should account for the high yield strength and the poor plasticity in the AC samples. The abundant mobile dislocations in the α bands and deformation-induced ω needles in the surrounding β phase led to the best plasticity in the FC samples among all Ti-12Nb samples. This study systematically studied the displacive and diffusional transformations and the plastic deformation in a Ti-12Nb alloy, the results might pave the way for designing low-modulus biomedical α′ Ti alloy with low content of β stabilizing elements and provide insights into tailoring of the phase transformations and mechanical properties in these Ti alloys.

A 2D Metal-Free Inorganic Covalent Framework: Synthesis, Crystal Structure, and Room-Temperature Phosphorescence.

The synthesis, crystal structure and room-temperature phosphorescence (RTP) of a 2D metal-free inorganic covalent framework ((H2en) [B5O8(OH)], named as CityU-12, and en represents for ethylenediamine) are reported. The precise structure information of CityU-12 has been disclosed through both single-crystal X-ray diffraction (SCXRD) analysis and low-dose high-resolution transmission electron microscopy (LD-HRTEM) study. The SCXRD results show that CityU-12 composes of 2D anionic B─O-based covalent inorganic frameworks with protonated ethylenediamine locating in the pore sites of 2D B─O layers while LD-HRTEM suggests that CityU-12 has an interplanar distance of 0.60nm for (00 ) crystal plane and 0.60nm for (10 ) crystal plane. The optical studies show that CityU-12 is an excellent nonconventional RTP material with the emission peak at 530nm and a lifetime of 1.5s. The quantum yield is 84.6% and the afterglow time is as long as 2.5s. This work demonstrates that metal-free B─O frameworks can be promising nonconventional phosphors for RTP.

Two-stage hydrothermal process driven visible light sensitive photocatalytic m-ZnWO4/m-WO3 heterojunction composite materials

The current study reports on the facile two-step hydrothermal synthesis of heterojunction m-ZnWO4/m-WO3 composite powders for visible light sensitive photocatalytic applications. The ZnWO4 particles start crystallizing on the surface of the WO3 powder in the second stage of the reaction in a basic medium. The phases of the composite powders were confirmed using x-ray diffraction analysis. The monoclinic cubic shaped WO3 and rod shaped ZnWO4 morphologies were disclosed from the field emission scanning electron microscope images. Strong interfacial adhesion between ZnWO4 and WO3 was unveiled from the high-resolution transmission electron microscopy study. The optimized composite 5ZW exhibits a calculated bandgap of 2.58 eV, positioning it within the visible light wavelength range (λ = 400–700 nm). Furthermore, there is a notable enhancement in the average lifetime of the electron–hole pair recombination rate, which is extended to 30.3 ns. The composite 5ZW demonstrated 96% methylene blue dye degradation efficiency within 420 min under visible light irradiation at pH 12. Due to the optimal phase fraction and strong interfacial adhesion between ZnWO4 and WO3, the heterojunction scheme seemed to be highly efficient in the 5ZW composite. Hence, it is believed that a two-step hydrothermal method can be a proficient route to prepare heterojunction composites m-ZnWO4/m-WO3 in alkali conditions with visible light active photodegradation efficiency.

Oxygen vacancy enhanced photocatalytic activity of Cu2O/TiO2 heterojunction

In this study, a method was developed to create oxygen vacancies in Cu2O/TiO2 heterojunctions. By varying the amounts of ethylenediaminetetraacetic acid (EDTA), sodium citrate, and copper acetate, Cu2O/TiO2 with different Cu ratios were synthesized. Tests on CO2 photocatalytic reduction revealed that Cu2O/TiO2's performance is influenced by Cu content. The ideal Cu mass fraction in Cu2O/TiO2, determined by inductively coupled plasma (ICP), is between 0.075% and 0.55%, with the highest CO yield being 10.22μmol g-1 h-1, significantly surpassing pure TiO2. High-resolution transmission electron microscopy and electron paramagnetic resonance studies showed optimal oxygen vacancy in the most effective heterojunction. Density functional theory (DFT) calculations indicated a 0.088 eV lower energy barrier for ∗CO2 to ∗COOH conversion in Cu2O/TiO2 with oxygen vacancy compared to TiO2, suggesting that oxygen vacancies enhance photocatalytic activity.

Single Crystal Growth and Nano-Structure Study in a Topological Dirac Metal, CoTe2-δ

A single crystal of a topological material, CoTe2-δ, has been grown via the chemical vapor transport method for a structural and electronic transport study. Single-crystal X-ray diffraction, powder X-ray diffraction, and high-resolution scanning electron microscope measurements confirm the high quality of the as-grown single crystals. In a high-resolution scanning electron microscopy study, a clear layered feature of the trigonal CoTe2-δ crystal was observed. Fractal features and mosaic-type nanostructures were observed on the as-grown surface and cleaved surface, respectively. The trigonal CoTe2-δ demonstrates a metallic ground state in transport measurements, with a typical carrier’s concentration in a 1021 cm−3 magnitude and a residual resistivity ratio of 1.6. Below 10 K, trigonal CoTe2-δ contains quite complicated magnetoresistance behavior as a result of the competing effect between Dirac states and possible spin fluctuations.

Complex magnetic behaviour and photocatalytic response in narrowed band gap NiO nanoparticles synthesized by novel Lepidagathis ananthapuramensis leaf extract

The present work focussed on the detailed investigation on structural, morphological, optical, photocatalytic, and magnetic properties of NiO nanoparticles (NPs) derived by a novel Lepidagathis ananthapuramensis leaf extract. The structural information using X-ray powder diffraction and Raman spectroscopy method indicates a single phase NiO hexagonal crystal structure for the sample calcined at ≥ 600 °C. Field emission scanning electron microscopy and high-resolution transmission electron microscopy studies noticed the various morphologies. UV–Visible, photoluminescence, and X-ray photoelectron spectroscopy confirmed the presence of both Ni2+ and Ni3+ ions with the narrowed band gap. Thorough magnetic studies indicate the existence of antiferromagnetic, ferromagnetic and superparamagnetic nature of NiO NPs. The photocatalytic activity of NiO NPs for the photocatalytic degradation of methylene blue dye in the presence of sunlight showed considerable results. This study can help us to deliver the wide range of properties which can be utilised in the field of magnetism and photocatalysis.

Dielectric analysis of surface modified nano-graphite: effects of frequency and thickness

The nano-graphite (NG) and acid modified nano-graphite (ANG) have been synthesized from graphite powder via mixture of strong acid (sulphuric acid and nitric acid) respectively by a soft chemistry route involving microwave, ultrasonic method and characterized by high-resolution electron microscopy (HR-TEM), scanning electron microscopy (SEM), fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), clearly demonstrated the successful synthesis of acid modified NG. SEM images confirmed the surface morphology of NG, and ANG and HR-TEM study shows the nanoparticles size of NG and ANG. FTIR data confirmed the presence of acid functional groups on the surface of synthesized NG powder. XRD data of NG and ANG shows that 2θ is at 26.43° and 0.336 nm is an interlayer distance (d). NG and ANG pellets have been prepared for their dielectric analysis with frequency for different thickness. The dielectric loss tangent (tanδ) spectra show relaxation peak with frequency and peak shifts due to presence of polar groups in the ANG. The capacitance values of NG and ANG decrease with frequency and increase with thicknesses due to the capacitive nature of nanoparticles. The dielectric permittivity decreases with frequency and increases with thickness due to the charge orientation and dipole moment change of functional groups of synthesized NG, and ANG. The electrical conductivity of NG and ANG nanoparticles increases with frequency and thickness of NG and ANG pellets due to the conductive nature. Electrical conductivity and dielectric permittivity of NG and ANG are found to highly rely on thickness, according to the dielectric evaluation.

Modified matrix of ZnO prismoid structures for improved photocatalytic activity: A theoretical and experimental insight

Currently, the world needs low-cost and high-performance photocatalysts to degrade the carcinogenic pollutant from water. In the present work, a modified ZnO matrix using Mg as a dopant has been reported with theoretical and experimental results to highlight its structure and functions on photocatalytic activity. A versatile chemical co-precipitation technique was employed to get the Mg-ZnO nanostructures. Structural characterization by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) studies show the formation of hexagonal wurtzite structures with no impurity phases. Optical studies confirm the formation of ZnO with intrinsic defects after modifying the matrix, which agrees with the band structure calculations computed using density functional theory (DFT). Mg-modified ZnO introduced intrinsic defects like vacancies and interstitials that have a great impact on applications like photocatalysis. Based on these supporting results we employed prepared samples for dye degradation, which performed well (80% degradation efficiency) in a short period of UV irradiation. This could be a promising technology for environmental remediation.

Exsolution-enhanced reverse water-gas shift chemical looping activity of Sr2FeMo0.6Ni0.4O6-δ double perovskite

This study investigates the structural evolution and redox characteristics of the double perovskite Sr2FeMo0.6Ni0.4O6-δ (SFMN) during hydrogen (H2) and carbon dioxide (CO2) redox cycles and explores the material performance in the Reverse Water-Gas Shift Chemical Looping (RWGS-CL) reaction. In-situ and ex-situ X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HRTEM) studies reveal that H2 reduction at temperatures above 800 °C leads to the exsolution of bimetallic Ni-Fe alloy particles and the formation of a Ruddlesden-Popper (RP) phase. A core–shell structure with Ni-Fe core and a perovskite oxide shell is formed with subsequent redox cycles, and the resulting material exhibits better performance and high stability in the RWGS-CL process. Thermogravimetric (TGA) and Temperature Programmed Reduction (TPR) and Oxidation (TPO) analyses show that the optimal reduction and oxidation temperatures for maximizing the CO yield are around 850 °C and 750 °C respectively, and that the cycled material is able to work steadily under isothermal conditions at 850 °C.

Glass transition temperatures and crystallization kinetics of a synthetic, anhydrous, amorphous calcium-magnesium carbonate.

We report the first calorimetric observations of glass transition temperatures and crystallization rates of anhydrous, amorphous calcium-magnesium carbonate using fast scanning differential scanning calorimetry. Hydrous amorphous Ca0.95Mg0.05CO3 · 0.5H2O (ACMC) solid was precipitated from a MgCl2-NaHCO3 buffered solution, separated from the supernatant, and freeze-dried. An aliquot of the freeze-dried samples was additionally dried at 250°C for up to 6 h in a furnace and in a high-purity N2 atmosphere to produce anhydrous ACMC. The glass transition temperature of the anhydrous Ca0.95Mg0.05CO3 was determined by applying different heating rates (1000-6000 K s-1) and correcting for thermal lag to be 376°C and the relaxational heat capacity was determined to be Cp = 0.16 J/(g K). Additionally, the heating rate dependence of the temperature that is associated with the corrected crystallization peaks is used to determine the activation energy of crystallization to be 275 kJ mol-1. A high-resolution transmission electron microscopy study on the hydrous and anhydrous samples provided further constraints on their compositional and structural states. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 1)'.

Thioglycolic acid-capped gold nanoparticle/cytochrome P450-2E1 electrochemical biosensor for isoniazid

Tuberculosis (TB) is one of the deadliest diseases in Africa and it is classified as a serious global health problem. A new threat associated with the disease is the emergence of multidrug-resistant TB (MDR-TB), which results from improper dose or non-compliance with a treatment regime. It is, therefore, important to determine a patient’s rate of TB drug metabolism at a point-of-care, in order to enable appropriate dose prescription. This work presents a novel enzymatic nanobiosensor for real-time determination of isoniazid (INH), which is a highly prescribed drug for TB treatment. The nanobiosensor consists of a cytochrome P450-2E1 (CYP2E1) isoenzyme covalently attached to a screen printed or disk gold electrode (Au), functionalized with thioglycolic acid-capped gold nanoparticle (TGA-AuNP). The nanomaterial was green-synthesized with banana peel extract (BPE) as the reducing agent. It exhibited an ultraviolet-visible spectroscopy (UV–Vis) signature absorption band for AuNP at 536 nm and a direct bandgap energy (Eg) value of 2.00 eV. Fourier transform infra-red spectroscopy (FTIR) was used to confirm the reduction of Au3+ to Au0. High-resolution transmission electron microscopy (HR-TEM) and high-resolution scanning electron microscopy (HR-SEM) studies indicated that TGA-AuNPs were polydisperse and exhibited spherical morphology. Bovine serum albumin (BSA) and CYP2E1 were attached to the TGA-AuNPs-modified Au electrode using glutaraldehyde (Glu) as binder, to form the nanobiosensor (BSA/CYP2E1/Glu/TGA-AuNPs/Au). Differential pulse voltammetric (DPV) responses of the nanobiosensor for INH were determined in 10 mM phosphate buffer (pH 7.4). The limit of detection (LOD) and the limit of quantification (LOQ) values of the nanobiosensor were 0.0556 μM INH and 0.1683 μM INH, respectively.

Enhanced Photocatalytic Applications of Chitosan Encapsulated Silver Sulphide Quantum Dots

This study explores the synthesis, properties, and applications of chitosan-encapsulated silver sulphide (Ag2S) quantum dots (QDs) for biological applications. The investigation focuses on the fluctuations in the physico-chemical characteristics of chitosan Ag2S QDs, which can be carefully studied due to their environmental activity. X-ray diffraction (XRD) measurements reveal that chitosan-coated Ag2S QDs exhibit higher-intensity peaks. The XRD analysis reports a range of crystallite sizes, with a minimum size of 8 nm and a maximum size of 12 nm. Fourier-transform infrared (FTIR) spectroscopy confirms the presence of chitosan through the detection of functional group peaks. High-resolution transmission electron microscopy (HRTEM) studies indicate that the size of the artificial quantum dots is 6 nm. Energy-dispersive X-ray spectroscopy (EDX) verifies the composition of chitosan-encapsulated Ag2S QDs. Moreover, the chitosan Ag2S quantum dots demonstrate exceptional photocatalytic activity, as evidenced by the degradation of 92% of methylene blue dye within one hour. This research provides valuable insights into the synthesis, properties, and potential applications of chitosan-encapsulated Ag2S quantum dots in diverse fields.

Chemically assembled 2D-van der Waals WSe2-WC heterostructured photo-anodes for electrochemical devices

Structural, optical, nanomorphological, photoresponsive and electrochemical charge transport characteristics of chemically assembled 2D-layered Tungsten Selenide (WSe2)-Tungsten Carbide (WC) heterostructure were examined. WC exhibited an optical bandgap of ∼3.2 eV, which did not show any optical absorption in the visible spectrum, and WSe2 showed the same in the spectral range of 200 nm-950 nm with an optical bandgap of ∼1.3 eV. Chemical assembly of WSe2-WC heterostructure was made in which the weight fraction of WSe2 was varied to understand its role in WC. Among the 2, 4, 6 and 8 wt% of WSe2 in WC, we observed that 6 wt% exhibited a dominant absorption and fluorescence emission (∼600 nm). High-resolution transmission electron microscopic studies revealed the d-spacing values of 0.24 nm and 0.33 nm for WSe2 and WC, respectively. Further, the presence of W (4f), Se (2d) and C (1 s) were traced out and studied by X-ray photoelectron spectroscopy. Raman modes A1g and EAg1 at 150 cm−1 and 250 cm−1 asserted the presence of WSe2 in WC which exhibited A1g at 150 cm−1. In addition, the individual WSe2 and WC along with WSe2-WC heterostructures were subjected to X-ray diffraction to study the crystallite size and strain-induced broadening due to the lattice deformation that occurred at the WSe2-WC heterostructures. Incorporating WSe2 into WC increased the photo-responsive behaviour and facilitated the charge transport as envisaged from the electrochemical impedance spectroscopic studies.

A highly active additive for magnesium hydride from the MgO–TiO2 mixed oxide family: Magnesium dititanate

This study explores that a promising additive, magnesium dititanate (MgTi2O5), promotes the hydrogen storage behavior of MgH2 by producing active in-situ catalytic species. Due to the creation of active species the dehydrogenation activation energy of MgH2 lowers by 95 kJ/mol. Differential scanning calorimetry (DSC) and hydrogen absorption/desorption kinetics studies provide evidence that MgTi2O5 performs better than the proven additive TiO2 for MgH2. The MgH2/MgTi2O5 composite samples tested by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) studies prove that oxidized Mg and Mg0·56Ti0.44 are the products of interaction between MgH2 and MgTi2O5. Formation of Mg-containing rock salt nanoparticles (MgO and/or MgxTiyOx+y) is identified to be the crucial step in the catalytic dehydrogenation reaction of MgH2/MgTi2O5 hydrogen storage system, which agrees well with the previous observation made for titania additive incorporated MgH2.

High-resolution cryo-electron microscopy structure of block copolymer nanofibres with a crystalline core.

Seeded growth of crystallizable block copolymers and π-stacking molecular amphiphiles in solution using living crystallization-driven self-assembly is an emerging route to fabricate uniform one-dimensional and two-dimensional core-shell micellar nanoparticles of controlled size with a range of potential applications. Although experimental evidence indicates that the crystalline core of these nanomaterials is highly ordered, a direct observation of their crystal lattice has not been successful. Here we report the high-resolution cryo-transmission electron microscopy studies of vitrified solutions of nanofibres made from a crystalline core of poly(ferrocenyldimethylsilane) (PFS) and a corona of polysiloxane grafted with 4-vinylpyridine groups. These studies show that poly(ferrocenyldimethylsilane) chains pack in an 8-nm-diameter core lattice with two-dimensional pseudo-hexagonal symmetry that is coated by a 27 nm 4-vinylpyridine corona with a 3.5 nm distance between each 4-vinylpyridine strand. We combine this structural information with a molecular modelling analysis to propose a detailed molecular model for solvated poly(ferrocenyldimethylsilane)-b-4-vinylpyridine nanofibres.

Fatigue and recrystallization evolution of carbide-free bainitic layer under high-stress rolling sliding contact

The rolling contact fatigue behavior of a newly developed bearing steel with carbide-free bainite, modified by a combination of tungsten inert gas surface melting and subsequent isothermal transformation was investigated. The rolling sliding tests were conducted to determine the vibration response and rolling contact fatigue life. The rolling contact fatigue life of the bainitic layer is 6.623 × 106 cycles, significantly higher than that of the commercial GCr15 steel sample (4.496 × 106 cycles). Focused ion beam technology and transmission Kikuchi diffraction studies on fatigue-tested samples showed that the toughness of the bainitic layer could be improved by the bainitic ferrite and retained austenite, which recrystallizes and forms nanocrystals during the rolling contact fatigue process. Furthermore, high-resolution transmission electron microscope study elucidated that the bainitic layer has better dislocation slip ability and is more prone to recrystallization on the rolling contact fatigue surface, preventing the rapid expansion of fatigue cracks. Moreover, the effect of dissolution of the Fe3C in GCr15 steel on the structure of distorted body-centered cubic crystals and pitting defects was also comparatively investigated.

α-In2Se3 Nanostructure-Based Photodetectors for Tunable and Broadband Response

The strong thickness-dependent narrow direct band gap of few-layer α-In2Se3 makes it a promising candidate for high-performance photodetectors. However, few researchers focus on the relationship between thickness and optoelectronic characteristics, and most results are based on the mechanically exfoliated α-In2Se3 nanoflakes. Herein, a reliable physical vapor deposition strategy to grow α-In2Se3 nanosheets with tunable thickness and submillimeter scale is reported. High-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) studies confirmed the high-quality growth of α-In2Se3 nanosheets. The back-gate field-effect transistors on SiO2 substrates display n-type semiconductor behavior. A systematical investigation of the optoelectronic properties reveals a thickness-dependent broadband response from visible (447 nm) to near-infrared (1550 nm) wavelengths with better and excellent performance obtained in thicker α-In2Se3 nanosheets than that in thinner devices. More importantly, a great improvement of the responsivity, detectivity, and external quantum efficiency (EQE) can be achieved by changing the thickness of In2Se3. The photodetector exhibits an outstanding photoresponsivity of 347.6 A/W, an ultrahigh detectivity of 1.5 × 1013 Jones, and an external quantum efficiency of 8.3 × 104%, which is superior to several α-In2Se3 nanostructure- or other two-dimensional (2D)-based photodetectors. The thickness-dependent broadband response characteristics make the α-In2Se3 nanostructure a promising candidate for multifunctional optoelectronic device applications.

Characterization of Solid-Solution and Aging Process in Mg-5 wt.%Sn Alloy

Firstly, the properties and the microstructure evolution of the solid-solution process of Mg-5 wt.%Sn were studied. From the motion analysis of resistivity and microhardness during solution treatment, the reasonable solution technology of Mg-5 wt.%Sn should be 12–16 h at 480 °C. After solution treatment at 480 °C for 16 h, the precipitating behavior in supersaturated solid solution. Mg-5 wt.%Sn alloy was investigated. In the aging process, it was observed that there were precipitated phases in the both grain and grain boundaries, and continuous inhomogeneous precipitation occurred along the grain boundaries, and continuous homogeneous precipitation happened in the grain. Transmission Electron Microscope (TEM) analysis indicated the plate- and lath-shaped precipitates within the grains and only the plate-shaped precipitates along the grain boundary. High-Resolution Electron Microscopy (HRTEM) studies have shown that metastable precipitates may occur during aging, coherently or semi-coherent with the matrix. Energy Dispersive Analysis by X-ray (EDAX) analysis showed that the Mg/Sn ratio was not actually constant, and the Sn content of the metastable phase was lower than that of the Mg2Sn equilibrium phase. X-ray diffraction (XRD) studies confirm the existence of this metastable phase, which is supposed to be GP zone and metastable Mg3Sn phase.

High-resolution and analytical electron microscopy in a liquid flow cell via gas purging.

Liquid-phase transmission electron microscopy (LPTEM) technique has been used to perform a wide range of in situ and operando studies. While most studies are based on the sample contrast change in the liquid, acquiring high qualitative results in the native liquid environment still poses a challenge. Herein, we present a novel and facile method to perform high-resolution and analytical electron microscopy studies in a liquid flow cell. This technique is based on removing the liquid from the observation area by a flow of gas. It is expected that the proposed approach can find broad applications in LPTEM studies.