Advanced Characterization Techniques Research Articles

Elucidating the Impact of Li3InCl6-Coated LiNi0.8Co0.15Al0.05O2 on the Electro-Chemo-Mechanics of Li6PS5Cl-Based Solid-State Batteries.

Li6PS5Cl has attracted significant attention due to its high Li-ion conductivity and processability, facilitating large-scale solid-state battery applications. However, when paired with high-voltage cathodes, it experiences adverse side reactions. Li3InCl6 (LIC), known for its higher stability at high voltages and moderate Li-ion conductivity, is considered a catholyte to address the limitations of Li6PS5Cl. To extend the stability of Li6PS5Cl toward LiNi0.8Co0.15Al0.05O2 (NCA), we applied nanocrystalline LIC as a 180 nm-thick protective coating in a core-shell-like fashion (LIC@NCA) via mechanofusion. Solid-state batteries with LIC@NCA allow an initial discharge specific capacity of 148 mA h/g at 0.1C and 80% capacity retention for 200 cycles at 0.2C with a cutoff voltage of 4.2 V (vs Li/Li+), while cells without LIC coating suffers from low initial discharge capacity and poor retention. Using a wide spectrum of advanced characterization techniques, such as operando XRD, XPS, FIB-SEM, and TOF-SIMS, we reveal that the superior performance of solid-state batteries employing LIC@NCA is related to the suppression of detrimental interfacial reactions of NCA with Li6PS5Cl, delamination, and particle cracking compared to uncoated NCA.

Defect Engineering in Bi-Based Photo/Electrocatalysts for Nitrogen Reduction to Ammonia.

Main group Bi-based materials have gained popularity as N2 reduction reaction (NRR) photo/electrocatalysts due to their ability to inhibit competitive H2 evolution reactions (HER) and the unique N2 adsorption activities. The introduction of defects in Bi-based catalysts represents a highly effective strategy for enhancing light absorption, promoting efficient separation of photogenerated carriers, optimizing the activity of free radicals, regulating electronic structure, and improving catalytic performance. In this review, we outline the various applications of state of the defect engineering in Bi-based catalysts and elucidate the impact of vacancies on NRR performance. In particular, the types of defects, methods of defects tailoring, advanced characterization techniques, as well as the Bi-based catalysts with abundant defects and their corresponding catalytic behavior in NRR were elucidated in detail. Finally, the main challenges and opportunities for future development of defective Bi-based NRR catalysts are discussed, which provides a comprehensive theoretical guidance for this field.

Accentuating the Reservoir Potentials of Balkassar Field by Delineating the Fracture Trends and Hydrocarbon Prospects with the Aid of Seismic Attributes.

Carbonates constitute a significant proportion of the world's hydrocarbon reserves, accounting for approximately 43%. Despite their substantial potential, accurately characterizing these reserves is a challenging task due to their complex and anisotropic nature. In the upper Indus basin of Pakistan, Eocene carbonates exhibit strong production capabilities. However, the Eocene reservoir (comprising the Chorgali and Sakesar formations) and the deeper Lockhart formation of the Paleocene age present a considerable challenge. The Chorgali formation is dolomitic in composition, featuring both primary and secondary porosity, while the Sakesar formation has only secondary porosity resulting from tectonic activity. The delineation of tectonically induced porosities is a highly demanding task that requires exceptional quality seismic and well data for reliable results. To address the complex heterogeneities present in the Eocene reservoir of the upper Indus basin, a variety of seismic attributes, such as sweetness, instantaneous frequency, amplitude, curvature, similarity variance, lateral continuity, and fault likelihood, have been employed in conjunction with fundamental interpreting techniques. These advanced seismic attributes greatly contribute to delineating fracture zones and identifying sweet spots with remarkable precision. They also enable a focus on high-frequency data content and differentiate between shale beds and reservoir zones based on frequency and amplitude. This helps in the concise marking of fractured zones to enhance our understanding of secondary porosity. Moreover, these attributes help delineate the continuity of reflectors and pinpoint disruptions caused by compression forces and tectonic activities. This study aims to capture the heterogeneity and complexity of reservoir zones to address a critical question regarding the Balkassar structure. The Western lobe of the field, which demonstrates promising oil production, outperforms the structurally higher Eastern part, which lags behind in production. This research seeks to recognize the geological elements contributing to the superior performance of the Western lobe and provide guidance for maximizing the potential of the Eastern lobe through advanced characterization techniques.

Aquivion-Based Spray Freeze-Dried Composite Materials for the Cascade Production of γ-Valerolactone.

The development of multifunctional catalysts is a necessary step to effectively carry out one-pot cascade reactions, such as that from furfural to γ-valerolactone. This research effort faces the challenge posed by the intrinsic limit of how many kinds of catalytic sites a single material can bear. In this work, the application of Spray-Freeze Drying (SFD) as a synthetic technique for the preparation of a wide range of innovative composite multi-functional catalysts is reported. Herein we show that by the proper combination of Aquivion as a highly active Brønsted acid catalyst and metal oxides as both support materials and Lewis acids (LAS) enable to achieve highly unique efficient and effective dual acid composite catalysts that are able to carry out the cascade reaction from furfural to γ-valerolactone. The dual catalytic system comprised of Aq/ZrO2 with 30 % polymer content prepared via spray-freeze drying exhibited GVL yields of 25 % after only 2 h at 180 °C and a remarkably high productivity of 4470 μmolGVL gCat -1 h-1, one of the highest reported results. Mechanistic studies based on experimental and advanced characterisation and spectroscopic techniques, such as, SEM, TEM, 15N MAS NMR and 19F MAS NMR indicate that activity arises from the proper tuning of BAS/LAS (Brønsted Acid Site/Lewis Acid Site) acidic properties.

ZIF‐8 decorated FeMo nanoparticles: H2 Production from the catalytic hydrolysis of ammonia‐borane

AbstractAmmonia‐Borane (AB) is considered a promising solid hydrogen storage material due to its high hydrogen content (19.6 wt%) and its use for safe hydrogen transport. The most effective way to produce H2 from AB is to perform the hydrolysis reaction in the presence of a suitable catalyst. In this study, Fe0.2Mo0.8/ZIF‐8 nanocatalyst was synthesized in two steps: (i) synthesis by following the colloidal synthesis technique by thermal decomposition of Mo(CO)6 and Fe(acac)3 in the presence of OM and ODE at high temperatures, and (ii) the resulting colloidal Fe0.2Mo0.8 NPs were decorated into ZIF‐8. The as‐prepared Fe0.2Mo0.8/ZIF‐8 catalyst was identified using advanced characterization techniques such as ICP‐OES, P‐XRD, SEM, SEM–EDX, TEM, TEM‐EDX, XPS, and BET. The catalytic activities of the Fe0.2Mo0.8/ZIF‐8 catalyst in the hydrolysis of AB were investigated in different parameters (temperature, catalyst [Fe0.2Mo0.8] and substrate [H3NBH3] concentration, and recyclability). The results show that high crystallinity Fe0.2Mo0.8 NPs with a uniform 1.31 ± 0.13 nm distribution were formed on the ZIF‐8 surface. Fe0.2Mo0.8/ZIF‐8 catalyst provides a maximum H2 generation rate of 184.2 mLH2 (g catalyst)−1 (min)−1 at 343 K. This uniquely cost‐effective, active and durable Fe0.2Mo0.8/ZIF‐8 catalyst has strong potential for H2‐based fuel cell (PEM: Proton Exchange Membrane) applications where AB is a suitable H2 carrier.Highlights FeMo NPs were synthesized by a colloidal synthesis method and decorated into ZIF‐8. FeMo/ZIF‐8 catalyst is an active catalyst in the hydrolysis of AB. FeMo/ZIF‐8 catalyst showed an initial TOF value of 449.85 mol(H2)·molFe0.2Mo0.8−1·h−1 in the AB hydrolysis at 338 K.

Evaluation of Particulate Matter Deposition Efficiency and Air Quality Improvement by Vertical Shrub and Climber Walls

Fine particulate matter poses a significant health risk indoors, making indoor air quality improvement crucial. Vertical greenery systems offer a promising solution, but selecting suitable plant species remains a challenge. This study evaluated the PM deposition and air quality impact of six ornamental plants (climbers and shrubs) in a controlled chamber. Almost all plants reduced CO2 by 20%, while PM deposition varied by species, with Petunia hybrid being the most efficient. Total leaf area showed the strong correlated with PM deposition. These findings confirm the potential of ornamental plants, particularly those with large total leaf area, for PM reduction in vertical greenery systems. Further research with a wider range of plants and advanced characterization techniques is needed to refine our understanding and develop practical guidelines for their effective use in indoor air purification.

Circumventing bottlenecks in H2O2 photosynthesis over carbon nitride with iodine redox chemistry and electric field effects

Artificial photosynthesis using carbon nitride (g-C3N4) holds a great promise for sustainable and cost-effective H2O2 production, but the high carrier recombination rate impedes its efficiency. To tackle this challenge, we propose an innovative method involving multispecies iodine mediators (I−/I3−) intercalation through a pre-photo-oxidation process using potassium iodide (suspected deteriorated “KI”) within the g-C3N4 framework. Moreover, we introduce an external electric field by incorporating cationic methyl viologen ions to establish an auxiliary electron transfer channel. Such a unique design drastically improves the separation of photo-generated carriers, achieving an impressive H2O2 production rate of 46.40 mmol g−1 h−1 under visible light irradiation, surpassing the most visible-light H2O2-producing systems. Combining various advanced characterization techniques elucidates the inner photocatalytic mechanism, and the application potential of this photocatalytic system is validated with various simulation scenarios. This work presents a significative strategy for preparing and applying highly efficient g-C3N4-based catalysts in photochemical H2O2 production.

Innovative Treatment of Ancient Architectural Wood Using Polyvinyl Alcohol and Methyltrimethoxysilane for Improved Waterproofing, Dimensional Stability, and Self-Cleaning Properties

This study introduced a novel two-step treatment to enhance the waterproofing, dimensional stability, and self-cleaning capabilities of ancient architectural wood. The process was initiated with the immersion of wood in an organic hybrid sol, composed of an acidic methyltrimethoxysilane (MTMS)-based silica sol and polyvinyl alcohol (PVA), which effectively sealed the wood’s inherent pores and cracks to mitigate degradation effects caused by aging, fungi, and insects. Subsequently, the treated wood surface was modified with an alkaline MTMS-based silica sol to form a functional superhydrophobic protective layer. The modification effectiveness was meticulously analyzed using advanced characterization techniques, including scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The results demonstrated substantial improvements: the modified wood’s water contact angle (WCA) reached 156.0°, and the sliding angle (SA) was 6.0°. Additionally, the modified wood showed a notable reduction in water uptake and moisture absorption, enhancing its dimensional stability. The superhydrophobic surface endowed the wood with excellent self-cleaning properties and robust resistance to pollution. Enhanced mechanical durability of superhydrophobic surface was observed under rigorous testing conditions, including sandpaper abrasion and tape peeling. Furthermore, the modification improved the thermal stability, compressive strength, and storage modulus of the wood. Collectively, these enhancements render this modification a potent methodology for the preservation and functional augmentation of historic architectural woodwork.

Experimental and computational approach of zirconium and chitosan doped NiCo2O4 nanorods served as dye degrader and bactericidal action

Different concentrations of zirconium with a fixed quantity (4 wt%) of chitosan (CS) doped nickel cobaltite (NiCo2O4) nanorods were synthesized using a co-precipitation approach. This cutting-edge research explores the cooperative effect of Zr-doped CS-NiCo2O4 to degrade the Eriochrome black T (EBT) and investigates potent antibacterial activity against Staphylococcus aureus (S. aureus). Advanced characterization techniques were conducted to analyze structural textures, morphological analysis, and optical characteristics of synthesized materials. XRD pattern unveiled the spinal cubic structure of NiCo2O4, incorporating Zr and CS peak shifted to a lower 2θ value. UV–Vis spectroscopy revealed the absorption range increased with CS and the same trend was observed upon Zr, showing a decrease in bandgap energy (Eg) from 2.55 to 2.4 eV. The optimal photocatalytic efficacy of doped NiCo2O4 within the basic medium was around 96.26 %, and bactericidal efficacy was examined against S. aureus, revealing a remarkable inhibition zone (5.95 mm).

Enhancing tribological properties of lubricated contacts via synergistic interactions of green silica nanoparticles and ZDDP

Zinc dialkyldithiophosphate (ZDDP) anti-wear lubricant additive contributes to significant harmful emissions and its replacement has become a priority. In this study, green silica nanoparticles were synthesized and optimized for concentration to serve as hybrid additives alongside ZDDP in lubricants, aiming to mitigate environmental concerns. A combination of 0.5 wt% silica nanoparticles, 0.5 wt% oleic acid (OA), and 0.75 wt% ZDDP demonstrated notable improvements, reducing ZDDP usage by ∼25 % while achieving significant tribological enhancements. At room temperature, coefficient of friction (COF) was reduced by ∼60 %, and wear was reduced by ∼70 %, while at 100 °C, COF was reduced by ∼80 %, and wear was reduced by ∼96 %. Advanced characterization techniques such as FESEM with EDS mappings, EPMA, and TOF-SIMS were employed to elucidate the underlying mechanisms for observed reduction in friction and wear.

Advancing photocatalytic activity through a green route: Bismuth ferrite@molybdenum trioxide heterostructure for sustainable water treatment

Photocatalysis has become increasingly pervasive in the chemical industry, profoundly impacting operational costs. However, an ideal photocatalyst must possess characteristics such as excellent reactivity, high selectivity, prolonged stability, low toxicity, and cost-effectiveness. Moreover, it should facilitate the efficient separation of photo-generated charge carriers, thereby minimizing recombination rates. In pursuit of advancing photocatalytic activity for sustainable water treatment, this investigation focused on synthesizing a groundbreaking photocatalyst, the Bismuth Ferrite@Molybdenum trioxide heterostructure, using an eco-friendly green chemistry technique with pomegranate extract. This approach aligns with the goal of environmental sustainability and represents a novel contribution to the field. Employing a comprehensive approach, advanced characterization techniques such as XRD, SEM, FT-IR, and UV–Vis were applied to analyze the material's structural, morphological, and optical properties. According to the characterization results, the heterostructure demonstrates superior photocatalytic efficiency, heightened crystallinity, and reduced recombination rates during dye degradation for water treatment compared to both individual photocatalysts. Notably, the composite catalyst exhibits a synergistic impact, outperforming individual BiFeO3 and MoO3 photocatalysts. SEM observations confirm the successful integration of rod-like MoO3 and cylindrical BiFeO3 morphologies, highlighting the strategic combination achieved through the green chemistry route. Furthermore, UV–Vis spectroscopy reveals key optical parameters, emphasizing a narrow bandgap energy of 2.74 eV with a high refractive index of 2.43 eV. The exceptional efficacy of the heterostructure in degrading dyes within the visible spectrum, surpassing expectations within a 4-hour timeframe, highlights its efficiency and precision. Remarkably, achieved degradation rates for Rhodamine B dye (98 %), Methyl Blue (96 %), and Methyl Orange dye (95 %) highlights the promising role of proposed photocatalytic system in effectively addressing water pollutant challenges.

Uncovering Atomic-scale Dynamics in Solid Catalysts via X-ray-based Methods.

Deciphering the structural intricacies of catalysts is essential to advance their atomic-scale engineering. Solid catalysts are complex, with structural features spanning multiple length scales and involving dynamics, which possess challenges in understanding structure-performance relationships. However, advanced operando X-ray characterization techniques, including X-ray absorption spectroscopy (XAS), diffraction (XRD), and pair distribution function analysis (PDF) allow elucidation of structural features under working conditions, discovering transitions from supported nanocrystals to dispersed sites, from solid solutions to supported nanoparticles, or structural changes at the local level. In this mini-review, we discuss case studies exploring the structure of catalysts over different lengths and time scales under different applications, such as CO2 hydrogenation to methanol or the dry reforming of methane, using a combination of operando XAS, XRD and PDF.

Recent Advances in Carbon Nitride Supported Single‐Atom Catalysts: Synthesis, Characterization, and Applications for CO2 Photoreduction

AbstractPhotoreduction of CO2 into value‐added chemicals and fuels is a promising green technology for solar‐to‐chemical conversion. Owing to the atomic utilization, unique metal‐support interaction, and unsaturated coordination active sites, single‐atom catalysts (SACs) have been attracting great attention in achieving high activity and selectivity of CO2 photoreduction reactions. On the other hand, carbon nitride (C3N4) with abundant periodically unsaturated coordination of nitrogen atoms can serve as an excellent support for anchoring metal single atoms. In this context, extensive research efforts have been paid in C3N4‐based SACs for CO2 photoreduction in recent years. In this review, we report the recent advances in C3N4 supported SACs for CO2 photoreduction. We start from the introduction of synthetic strategies of various C3N4 supported metal SACs. Secondly, the main advanced characterization techniques and calculation methods for identifying the single‐atoms and their coordination environments of C3N4‐based SACs are summarized. Thirdly, some state‐of‐the‐art works on the rational design of C3N4‐based SACs and their applications in CO2 photoreduction are introduced. Lastly, we briefly summarize the main challenges and propose important perspectives of C3N4‐based SACs in CO2 photoreduction. This review is expected to provide some useful guidelines for the development of efficient and stable C3N4‐based SACs for CO2 photoreduction.

Regulating the Critical Intermediates of Dual-Atom Catalysts for CO2 Electroreduction.

Electrocatalysis is a very attractive way to achieve a sustainable carbon cycle by converting CO2 into organic fuels and feedstocks. Therefore, it is crucial to design advanced electrocatalysts by understanding the reaction mechanism of electrochemical CO2 reduction reaction (eCO2RR) with multiple electron transfers. Among electrocatalysts, dual-atom catalysts (DACs) are promising candidates due to their distinct electronic structures and extremely high atomic utilization efficiency. Herein, the eCO2RR mechanism and the identification of intermediates using advanced characterization techniques, with a particular focus on regulating the critical intermediates are systematically summarized. Further, the insightful understanding of the functionality of DACs originates from the variable metrics of electronic structures including orbital structure, charge distribution, and electron spin state, which influences the active sites and critical intermediates in eCO2RR processes. Based on the intrinsic relationship between variable metrics and critical intermediates, the optimized strategies of DACs are summarized containing the participation of synergistic atoms, engineering of the atomic coordination environment, regulation of the diversity of central metal atoms, and modulation of metal-support interaction. Finally, the challenges and future opportunities of atomically dispersed catalysts for eCO2RR processes are discussed.

Characterization of phytosynthesized niobium oxide nanoparticle for efficient conversion of Grewia asiatica L. waste seed oil into sustainable fuel

The production of bioenergy and bioproducts from streams of biowaste has ignited interest in fostering a circular economy worldwide. This study investigates the potential of transforming Grewia asiatica L. waste seed oil into sustainable biodiesel using green-synthesized niobium oxide nanoparticle. Niobium oxide nanocatalyst was synthesized using aqueous leaf extract of Fumaria indica L. Advanced characterization techniques were employed to confirm the pure and nano-scale nature of the synthesized niobium oxide nanocatalyst. The synthesized nanocatalyst exhibited an average particle size of 31 nm, resulting in efficient catalytic activity that persited through the fifth cycle of transesterification. An optimum biodiesel yield of 90% was achieved under reaction conditions of a methanol to oil molar ratio of 9:1, a reaction time of 180 min, a temperature of 60 °C and a catalyst load of 0.32 (wt. %). Results of Gas chromatography mass spectrometry (GC–MS) analysis of G. asiatica-derived biodiesel revealed 5, 8-Octadecadienoic acid methyl ester as the primary fatty acid methyl ester, with the highest concentration. The fuel properties of G. asiatica-derived biodiesel complied with international standards. The minimal sulphur content of 0.0001% highlights the clean, environmentally benign and cost-effective nature of biodiesel synthesized from G. asiatica waste seed oil. This study contributes to the renewable alternative effort toward transitioning from a linear economy to a circular bioeconomy.

Enhancing in-situ tetracycline degradation in urine environment using boron-modified sewage sludge biochar: Mechanism of carbonate radical promotion

In this work, we reveal the influencing factors and mechanisms of tetracycline removal by peroxydisulfate activated with boron-modified sewage sludge biochar in urine. Advanced characterization techniques showed that the introduced BCO2 and BC2O were the main activation sites for peroxydisulfate, which maintained a high removal rate of tetracycline in synthetic and actual urine (86.48% and 77.35%). HCO3−/CO32− and some organic matter in the urine contributed to the degradation of the tetracycline. Theoretical calculations showed that CO32− in urine could be efficiently adsorbed by the introduced B atoms and converted to CO3·− by peroxydisulfate to assist the degradation of tetracycline, which was attributed to the special electronic structure of the B atoms as well as the strong electron-enrichment ability of the neighboring O atoms. The potential toxicity of tetracycline and its degradation intermediates was further explored, revealing a significant reduction in toxicity during boron-modified sewage sludge biochar/ peroxydisulfate treatment.

Exploring the peel ash of musa acuminate as a heterogeneous green catalyst for producing biodiesel from Niger oil: A sustainable and circular bio economic approach

Currently, biodiesel stands as a sustainable and renewable alternative to depleting fossil fuels like petro-diesel. The widespread adoption of biodiesel production holds promise for enhancing environmental quality by reducing greenhouse gas emissions and promoting societal-economic development. In line with this, our research has focused on synthesizing biodiesel from the novel and edible seed oil of Niger oil, utilizing a green catalyst derived from the calcination of banana peel ash at 600 °C for 4 h. Advanced characterization techniques, including X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Diffraction X-Ray (EDX), Thermogravimetric Analysis (TGA), X-ray Photoelectron Spectroscopy (XPS), and Fourier-transform Infrared Spectroscopy (FT-IR), were employed to assess the catalytic activity of the catalyst. Under optimized reaction conditions a methanol-to-oil molar ratio of 15:1, catalyst loading of 1% (wt.%), reaction time of 4 h, and temperature of 70 °C we achieved a commendable biodiesel yield of 92.30%. Gas Chromatography (GC) analysis of the biodiesel revealed four distinctive peaks corresponding to methyl esters. Results from Fourier-transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) confirmed the presence of methyl esters in the biodiesel sample. Additionally, the fuel properties of the biodiesel, including density (0.904 kg/m3), kinematic viscosity (4.56 cst), cloud point (3 °C), pour point (2.8 °C), and flash point (149 °C), complied with international ASTM D standards. In conclusion, Niger biodiesel emerges as a highly promising, eco-friendly, reusable, and cost-effective feedstock for biodiesel production, thereby holding significant potential for advancing sustainable energy solutions.

Unveiling aqueous lithium-ion batteries via advanced modelling and characterisation: A review

Aqueous lithium-ion batteries (ALIBs) are promising candidates for sustainable energy storage, offering great advantages in safety, cost, and environmental impact over the conventional nonaqueous LIBs. This paper delves into the forefront of ALIB research in electrolyte formulations, electrode materials, and design strategies of ALIBs that have stemmed from the integration of advanced modelling and characterisation techniques. A detailed examination of multiscale modelling approaches, e.g., density functional theory (DFT), molecular dynamics (MD), microscopic and spectroscopic techniques, e.g., X-ray, Raman, and particularly in situ and in operando methods that provide real-time observations of battery processes, is carried out. We note that the synergy between modelling and characterisation techniques have offered unprecedented insights into the fundamental processes governing ALIB performance, however, more methods that have been demonstrated effective in commercial LIBs, can be employed and contribute to resolving the current bottlenecks of ALIBs. The models at mesoscale, continuum-scale and even larger scales can supplement DFT and MD to investigate the electrochemical processes in electrode-electrolyte interface, bulk electrolyte, porous electrodes, and prototype cells, and cooperate with essential measurements to characterise physicochemical properties of aqueous electrolytes, which are not widely discussed. Other microscopic, structural, and multi-physical characterisations, such as scanning transmission electron microscopy, computed tomography, thermography, and acoustic techniques can provide more insights into lithium intercalation, phase change and degradation, inspiring the theory and model development of ALIBs. By amalgamating the current state-of-the-art and existing challenges, this paper paves the way for future prospects in ALIBs.

Defect Engineering in Transition Metal Dichalcogenide-Based Gas Sensors

Since the discovery of innovative two-dimensional (2D) materials, significant efforts have been dedicated to exploring their intriguing properties and emerging applications. Among all candidates, transition metal dichalcogenides (TMDs) have proven to be exceptional for gas sensing, while defects engineering has been introduced to modify the pristine TMDs for better gas sensing performances. In this review, we systematically summarize types of defects, advanced characterization techniques, and state-of-the-art controllable synthetic methods. Various types of defects in TMDs can induce diverse changes in chemical and electron structures, which are closely correlated with gas sensing ability. Therefore, connections between defects and gas sensing mechanisms and performances have been addressed based on both defect categories and electron affinity of gases. This review will be a guide for researchers in defective materials and open up the field of precisely synthesis chemistry and deepen the understanding of the underlying effects of defects in other 2D materials.

Evaluating Polyacrylic Acid as a Universal Aqueous Binder for Ni-Rich Cathodes NMC811 and Si Anodes in Full Cell Lithium-ion Batteries.

Silicon (Si) and silicon/graphite (Si/Gr) composite anodes are promising candidates due to their high theoretical capacity, low operating potential and natural abundance for high energy density Li-ion batteries. Green electrode production, eliminating organic volatile solvents require advancement of aqueous electrodes. Engineering the binder plays a critical role for improving waterborne electrodes. Lithium substituted polyacrylic acid LiPAA has been demonstrated as a promising binder for Si/Gr anodes and for Ni-rich cathodes in different cell configurations. LiPAA is utilized to minimize the volume expansion during cycling for Si/Gr anodes. LiPAA is formed in situ during cathode slurry preparation to regulate the pH and dimmish the Li loss. Using advanced characterization techniques, we investigated the slurries, electrodes, and active material reaction with LiPAA and its effect to the cycling performance. Our results indicate that the performance of high Si containing anode is limited by the amount of Si in the electrode. The failure mechanism with respect to high Si content was studied thoroughly. Aqueous processed cathodes with LiPAA binder in combination with Si anodes outperformed NMP based cathodes. Hence, LiPAA was successfully utilized as an active binder for both a high Si containing anode and for a Ni rich cathode.