Vibrational Spectroscopic Techniques Research Articles

Toward Plasmon-Controlled Generation of the Activating Ag Hotspot Nanospheres for Quantitative SERS Analysis

Introduction: Surface-enhanced Raman scattering (SERS) has attracted enormous concern as a robust vibrational spectroscopy technique with widespread applications, primarily for the ultrasensitive detection of low-concentration molecules and selective identification. Nevertheless, the optimization of SERS efficiency has been impeded by limitations in controlling the size of nanoparticles utilized in this technique. Method: In this study, the morphology, structure, chemical components, and optical properties of the as-synthesized Ag nanoparticles (Ag NPs) via a hydrothermal method were thoroughly investigated by sophisticated analyses. The synthesized Ag NPs were characterized for its morphological characteristics using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis absorption spectroscopy, Raman spectroscopy, and assessed for their SERS performance in detecting organic substances including Crystal Violet (CV) and Rhodamine B (RhB). Results: The results showed that Ag NPs with different sizes could be obtained from 10 to 30 nm. These sizes corresponded to the duration of the hydrothermal method, which was 15, 20, and 25 hours, respectively. The optimal sample exhibited the capability to detect dye molecule solutions at diluted-low concentrations as low as 10-8 M. Conclusion: Through these results, we contribute to advancing the understanding of tailored nanoparticle synthesis for superior SERS performance, thus opening avenues for enhanced molecular detection in various applied analytical fields.

Comparative evaluation of acetaminophen form (I) in commercialized paracetamol brands

The vibrational spectroscopy (FT-IR/Raman) and X-ray diffraction techniques are combined alongside the principal component analysis (PCA) as novel integrated analytical techniques to comparatively investigate latent chemical information and quality discrepancies regarding twelve (12) commercialized paracetamol (APAP) brands. This research aim is to present an advanced computational screening approach using spectroscopic and X-ray diffraction techniques with PCA as a tool to investigate the structural properties of pharmaceutical solid drugs by vibrational mode and diffraction pattern analyzes. Herein, the acquired vibrational, absorption, and diffraction datasets of APAP functionalities were collected at spectra and diffraction regions of intense peaks to develop predictive PCA models. Interestingly, the PCA models invalidate drug falsification in all the brands and predicted dissimilarities arising from observed differences in the vibrational/absorption modes of APAP form (I) in some brands due to excessive use of cheap (fillers and hydrocolloid alternatives) excipients. The PCA-PXRD model unveils discrepancies regarding the contrasting diffraction patterns (structure-property relationships) observed for APAP form (I) in the brands, which suggests differences in their pharmacokinetic properties cause an unapparent structural modification. Nevertheless, the comparative drug release studies present a%CDR between 93 and 98% in 30 min for all the brands, thus, structural modifications of APAP form (I) as observed in some brands show no serious effects on the%CDR and/ or solubility. Finally, it is expected that this work will contribute to the advances in screening techniques toward addressing the global drug challenges, especially in developing countries.

Electron acceptor, excitation energies, oscillatory strength, spectroscopic and solvent effects on 5-amino-4,6-dichloro-2-(propylthio) pyrimidine - anticancer agent

The characteristics of Five-amino-4,6-dichloro-2-(propylthio) pyrimidine (5ADCPP) are studied using theoretical vibrational spectroscopic techniques including spectroscopy in the FT-IR, FT-Raman, and UV–Visible ranges. Raman scattering, infrared penetration intensities, vibrational modes, and the optimized geometric figure make use of the theory of density functionals (DFT). The HOMO and LUMO molecular orbitals indicate the molecule underwent an excellent shift in charge. The NBO approach was used to study the relationships between donors and recipients. Topological studies are carried out with AIM theory and LOL and ELF studies are done on the molecule. The hyperpolarizability calculation indicates that the 5ADCPP has excellent NLO properties. By using UV–Vis studies at different solvents the electronic transition is obtained. Fukui function and molecular electrostatic potential (MEP) research are covered. Drug-likeness has been carried out. The target proteins and the ligand 5ADCPP are used in molecular docking to get the cancer-preventive action.

Molecular Metabolic Fingerprinting Approach to Investigate the Metabolic Alterations in Heart, Aorta and Renal Tissues of Nitric Oxide Deficient Hypertensive Rats

Hypertension is the leading cause of cardiovascular diseases (CVD) globally. It is well known that the incidence of several CVDs, including stroke, coronary heart disease, and peripheral artery disease, is closely linking to hypertension. Nitric oxide is the imperative regulator of the vascular system and its deficiency leads to elevated blood pressure and metabolic alterations in the tissues such as liver, kidney heart and aorta. Fourier transform infrared spectroscopy (FTIR) is a vibrational spectroscopic technique that uses infrared radiation to vibrate molecular bonds with in the sample that absorbs it and different vibrational spectra can be used to explore the qualitative and quantitative constituent of macromolecules. The aim of this study was to compare molecular changes in the tissues of normal control rats with nitric oxide deficient hypertensive rats. Hypertension was induced in male albino Wistar rats by oral administration of L-NAME (40mg/kg body weight) dissolved in drinking water daily for four weeks. Results indicate that FTIR can successfully identify the molecular changes in hypertensive groups. Overall, the findings demonstrate that in International Journal of Scientific Research in Engineering and Management (IJSREM) Volume: 06 Issue: 12 | December - 2022 Impact Factor: 7.185 ISSN: 2582-3930 © 2022, IJSREM | www.ijsrem.com DOI: 10.55041/IJSREM17171 | Page 2 nitric oxide-deficient animals, the heart, kidney and aortic tissues metabolic programs were altered through an increase in structural modifications in proteins and triglycerides and a quantitative alteration in proteins lipids and transcription factors. Key words: Hypertension; metabolites; FTIR spectroscopy; nitric oxide

Detection of Alzheimer’s by Machine Learning-assisted Vibrational Spectroscopy in Human Cerebrospinal Fluid

Nowadays, the diagnosis of Alzheimer’s disease is a complex process that involves several clinical tests. Cerebrospinal fluid contains common Alzheimer-related biomarkers that include amyloid beta 1-42 (Aβ1-42) and tau proteins. In this work, we propose vibrational spectroscopy techniques supported by machine learning for the detection of biomarkers in cerebrospinal fluid that are related with Alzheimer’s by prediction models. Vibrational spectroscopy provides the entire biochemical composition of the body fluid, and thus, small but typical physiological changes related with the pathology can be ascertained. Within a machine learning framework, Raman and FTIR spectra were analyzed, which were taken from samples of healthy volunteers in comparison with samples from patients clinically diagnosed with Alzheimer’s. We find that a logistic regression model can discriminate between healthy control and Alzheimer’s patients with a precision of 98%, when the input for the model combines data from both vibrational spectroscopy methods. Our approach shows high discriminative capabilities and constitutes a proof of concept for an alternative and accurate tool for the diagnosis of Alzheimer’s disease.

A Review on Spectroscopy and its Classification

Spectroscopy, in this study, is introduced as a non-invasive and visual in situ diagnostic tool for mean plasma parameters, such as negative ion densities. Diagnostic lines for various plasma parameters and simplified analytical methods are identified and ready for direct use. Results derived from RF generated negative ion sources are emphasized, including an extract were negative ion current density correlates plasma parameters. Losses in the extraction system are calculated using beam emission spectroscopy. VSMs are sensitive to IR and chromophores are well adapted to their electrical environment, and when combined with synchronous nonlinear vibration tests, spontaneous fluctuation in condensed induced chemical and physical processes can be studied. Grids can be used immediately, both linearly and nonlinearly, to demonstrate the working principles of vibrational spectroscopy techniques. A molecular spectrum is vibrational or close to one of the electronic oscillations charged oscillates in a molecule with an external electromagnetic field. We note first that it involves interactions of particles. Characterization of the vibrational spectrum of a molecule absorbed on a solid surface bond and about the local chemical environment can provide insight.

Diagnostic accuracy of Vibrational spectroscopy in the diagnosis of oral potentially malignant and malignant disorders: A systematic review and meta-analysis.

Oral malignant and potentially malignant conditions affect several people worldwide each year. The early diagnoses of these conditions play an important role in prevention and recovery. Vibrational spectroscopy techniques such as Raman spectroscopy (RS) and Fourier-transform infrared (FTIR) spectroscopy are used in the early, non-invasive, label-free diagnosis of malignant and pre-malignant conditions, and are areas of active research. However, there is no conclusive evidence suggesting the translatability of these methods into clinical practice. This systematic review and meta-analysis presents pooled evidence for RS and FTIR methods in the detection of malignant and potentially malignant conditions of the oral cavity. Electronic databases were searched for published literature on RS and FTIR in the diagnosis of oral malignant and potentially malignant conditions. The pooled sensitivity, specificity, diagnostic accuracy, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), pre-test, and post-test probability were then calculated using the random-effects model. A subgroup analysis was conducted separately for RS and FTIR methods. A total of 12 studies were included (8 of RS; 4 of FTIR) as per the eligibility criteria. The pooled sensitivity and specificity of the vibrational spectroscopy methods were calculated to be 0.99 (95% confidence interval [CI]: 0.90, 1.00) and 0.94 (95% CI: 0.85, 0.98), respectively. The area under the curve (AUC) for the summary receiving operator characteristic curve was found to be 0.99 (0.98-1.00). Therefore, the results obtained in this study suggest that the RS and FTIR methods offer great potential to be used in the early diagnosis of oral malignant and pre-malignant conditions.

Optical photothermal infrared spectroscopy with simultaneously acquired Raman spectroscopy for two-dimensional microplastic identification

In recent years, vibrational spectroscopic techniques based on Fourier transform infrared (FTIR) or Raman microspectroscopy have been suggested to fulfill the unmet need for microplastic particle detection and identification. Inter-system comparison of spectra from reference polymers enables assessing the reproducibility between instruments and advantages of emerging quantum cascade laser-based optical photothermal infrared (O-PTIR) spectroscopy. In our work, IR and Raman spectra of nine plastics, namely polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, silicone, polylactide acid and polymethylmethacrylate were simultaneously acquired using an O-PTIR microscope in non-contact, reflection mode. Comprehensive band assignments were presented. We determined the agreement of O-PTIR with standalone attenuated total reflection FTIR and Raman spectrometers based on the hit quality index (HQI) and introduced a two-dimensional identification (2D-HQI) approach using both Raman- and IR-HQIs. Finally, microplastic particles were prepared as test samples from known materials by wet grinding, O-PTIR data were collected and subjected to the 2D-HQI identification approach. We concluded that this framework offers improved material identification of microplastic particles in environmental, nutritious and biological matrices.

Computational investigation of hydrogen-induced phonon changes in carbon fiber

Optical vibrational spectroscopy has shown promise as a noninvasive means of monitoring the mechanical properties of carbon fiber (CF), which is increasingly used for industrial and consumer purposes. However, interpretation of optical vibrational spectra for solid materials is inferential, particularly when defects are present. Because inelastic neutron scattering (INS) spectroscopy is not subject to selection rules, the full vibrational spectra can be measured. And, identifying correlations between INS features and tensile properties can assist in the interpretation of spectra from more commonly used optical vibrational spectroscopic techniques, such as Raman and infrared (IR) spectroscopy. Recent INS experiments on high-performance commercial carbon fibers showed features near 900 and 1100 cm−1 in addition to a broad feature near 3000 cm−1 that increased in intensity with decreasing tensile strength. These features were assigned to hydrogen defects. In the present work, we use density functional theory to simulate the INS spectra of several hydrogen defect geometries in graphite as a model for carbon fiber structure units, confirming the experimental assignment of these peaks to hydrogen modes and providing insights into the structure and lattice dynamics of the defects.

Dynamics of hydrogen bond reorganization in the S1(ππ*) state of 9-Anthracenecarboxaldehyde

Effect of solvent polarity and hydrogen bonding interaction on the excited state dynamics of 9-Anthracenecarboxaldehyde (9-ACD) have been investigated using steady state and time-resolved electronic and vibrational spectroscopic techniques. Photophysical properties and dynamics of the excited states are seen to be more sensitive to intermolecular hydrogen bonding ability of the solvent, rather than its polarity. FTIR studies reveal formation of complexes with the protic solvents via formation of conventional hydrogen bond at the carbonyl site of 9-ACD molecule. In strong hydrogen bond donating solvents, namely, 2, 2, 2-trifuoroethanol (TFE) and 1, 1, 1, 3, 3, 3-hexafluoroisopropanol (HFIP), nearly all the molecules of 9-ACD in solution remain engaged in complex formation leaving insignificant number of molecules remaining free in solution. In aprotic solvents, the S1 state is short-lived (the lifetime is only a few tens of ps) and intersystem crossing (ISC) is the major deactivation pathway (the triplet yield is near unity). However, in strong hydrogen bond donating solvents, the S1 state lifetime is long (a few ns) because the deactivation pathway for the S1 state via the triplet manifold is blocked. Both the ultrafast time-resolved electronic and vibrational spectroscopy studies in TFE and HFIP reveal that hydrogen bond reorganization process following photoexcitation of the hydrogen bonded complex is the only relaxation process undergone by the S1 state in sub-100 ps time domain. However, the time-resolved IR (TRIR) spectroscopy studies further reveal the possibility of formation of aromatic π- hydrogen bonding and reorganization of the hydrogen bond at this site makes the major contribution towards the S1 state relaxation process in strong hydrogen bond donating solvents.

Recent Progress on Solid Substrates for Surface-Enhanced Raman Spectroscopy Analysis.

Surface-enhanced Raman spectroscopy (SERS) is a powerful vibrational spectroscopy technique with distinguished features of non-destructivity, ultra-sensitivity, rapidity, and fingerprint characteristics for analysis and sensors. The SERS signals are mainly dependent on the engineering of high-quality substrates. Recently, solid SERS substrates with diverse forms have been attracting increasing attention due to their promising features, including dense hot spot, high stability, controllable morphology, and convenient portability. Here, we comprehensively review the recent advances made in the field of solid SERS substrates, including their common fabrication methods, basic categories, main features, and representative applications, respectively. Firstly, the main categories of solid SERS substrates, mainly including membrane substrate, self-assembled substrate, chip substrate, magnetic solid substrate, and other solid substrate, are introduced in detail, as well as corresponding construction strategies and main features. Secondly, the typical applications of solid SERS substrates in bio-analysis, food safety analysis, environment analysis, and other analyses are briefly reviewed. Finally, the challenges and perspectives of solid SERS substrates, including analytical performance improvement and largescale production level enhancement, are proposed.

Vibrational Spectroscopy Insight into the Electrode|electrolyte Interface/Interphase in Lithium Batteries

AbstractLithium‐ion batteries (LIBs) have transformed the use of mobile electronics and storage technologies. Alongside advances in materials, an in‐depth understanding of the interfacial phenomena and interphase formation mechanisms in LIBs is crucial. Interphases are widely recognized as the most important and the least understood components of LIBs and play a direct role in defining cell performance, cyclability, and safety. This article presents a review of recent developments in vibrational spectroscopy techniques of Raman, infrared, and sum‐frequency generation spectroscopies to probe the fundamental aspects of interphases on the anode and cathode of LIBs. First the vibrational spectroscopy techniques and their relevant technical considerations for interphase characterization are briefly introduced. In the next step, the latest studies on the fundamental properties, composition, and structure of interphases employing vibrational spectroscopy techniques are presented. This review focuses on in situ/operando investigations; however, post‐mortem studies are also discussed briefly.

Applications of Single-Molecule Vibrational Spectroscopic Techniques for the Structural Investigation of Amyloid Oligomers.

Amyloid oligomeric species, formed during misfolding processes, are believed to play a major role in neurodegenerative and metabolic diseases. Deepening the knowledge about the structure of amyloid intermediates and their aggregation pathways is essential in understanding the underlying mechanisms of misfolding and cytotoxicity. However, structural investigations are challenging due to the low abundance and heterogeneity of those metastable intermediate species. Single-molecule techniques have the potential to overcome these difficulties. This review aims to report some of the recent advances and applications of vibrational spectroscopic techniques for the structural analysis of amyloid oligomers, with special focus on single-molecule studies.

PSI-18 Effect of Heat Processing Methods on Carbohydrate Subfractions and Degradation in Relation to Carbohydrate Molecular Spectral Profile of Barley Grain Using Advanced Molecular Spectroscopy in Ruminants

Abstract To our knowledge, there are few studies on the association between carbohydrate molecular structure spectral profiles of barley grain and ruminant-relevant nutritional characteristics. This study aimed to study associate processing-induced changes in carbohydrate molecular structure with changes in ruminant-relevant carbohydrate nutritional profiles. The heat processing methods included: dry roasting, autoclaving, and microwave irradiation. The ruminant-relevant carbohydrate nutritional profiles were determined which included carbohydrate chemical profiles, carbohydrate subfractions, ruminant-relevant carbohydrate digestion. The molecular structure spectral profiles were determined using vibrational molecular spectroscopy (ATR-FT/IR). The results showed that heat related processing significantly induced carbohydrate molecular spectral profiles. The heat related processing also significantly changed ruminant-relevant nutritional characteristics. There was an association between processing induced carbohydrate molecular structure changes and ruminant-relevant carbohydrate nutritional profiles. The advanced vibrational molecular spectroscopic technique (ATR-FTIR) shows the great potential as a fast analytical tool to predict ruminant-relevant carbohydrate nutritional characteristics.

Raman spectroscopy as a novel technique for the identification of pathogens in a clinical microbiology laboratory

Raman spectroscopy is a vibrational spectroscopic technique with which the molecular fingerprint of a microorganism can be elucidated in 1 hr or less. In our study, the utility of this method as a rapid technique for the detection of different pathogens in a clinical microbiology laboratory was tested based on their unique spectra. The reference strains from American Type Culture Collection for frequently encountered pathogens such as Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, and Pseudomonas aeruginosa were used to capture the signature spectra of these pathogenic species using confocal Raman microscopy. Furthermore, a representative reference library was constructed using the spectra of these standard strains as well as the clinical isolates. The study revealed unique spectral outputs for each bacterial species studied. Importantly, the entire procedure could be performed in an hour. With the development of an extensive database, the spectra of unknown samples can be matched with those in the library, and thus, a new identification system can be developed.

Investigation of Water Interaction with Polymer Matrices by Near-Infrared (NIR) Spectroscopy

The interaction of water with polymers is an intensively studied topic. Vibrational spectroscopy techniques, mid-infrared (MIR) and Raman, were often used to investigate the properties of water–polymer systems. On the other hand, relatively little attention has been given to the potential of using near-infrared (NIR) spectroscopy (12,500–4000 cm−1; 800–2500 nm) for exploring this problem. NIR spectroscopy delivers exclusive opportunities for the investigation of molecular structure and interactions. This technique derives information from overtones and combination bands, which provide unique insights into molecular interactions. It is also very well suited for the investigation of aqueous systems, as both the bands of water and the polymer can be reliably acquired in a range of concentrations in a more straightforward manner than it is possible with MIR spectroscopy. In this study, we applied NIR spectroscopy to investigate interactions of water with polymers of varying hydrophobicity: polytetrafluoroethylene (PTFE), polypropylene (PP), polystyrene (PS), polyvinylchloride (PVC), polyoxymethylene (POM), polyamide 6 (PA), lignin (Lig), chitin (Chi) and cellulose (Cell). Polymer–water mixtures in the concentration range of water between 1–10%(w/w) were investigated. Spectra analysis and interpretation were performed with the use of difference spectroscopy, Principal Component Analysis (PCA), Median Linkage Clustering (MLC), Partial Least Squares Regression (PLSR), Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) and Two-Dimensional Correlation Spectroscopy (2D-COS). Additionally, from the obtained data, aquagrams were constructed and interpreted with aid of the conclusions drawn from the conventional approaches. We deepened insights into the problem of water bands obscuring compound-specific signals in the NIR spectrum, which is often a limiting factor in analytical applications. The study unveiled clearly visible trends in NIR spectra associated with the chemical nature of the polymer and its increasing hydrophilicity. We demonstrated that changes in the NIR spectrum of water are manifested even in the case of interaction with highly hydrophobic polymers (e.g., PTFE). Furthermore, the unveiled spectral patterns of water in the presence of different polymers were found to be dissimilar between the two major water bands in NIR spectrum (νs + νas and νas + δ).

Revealed interactive association between macro-molecular structures and true nutrition supply in cool-season adapted CDC chickpeas and CDC barley using advanced vibrational molecular spectroscopic techniques

Recently, an interactive association between molecular structures and nutrition of protein could be used for evaluation of truly absorbable nutrient supply, nutrient utilization and availability. However, there was no study found in cool-season adapted chickpeas. The objectives of this study were to: (1) reveal an interactive association between macro-molecular structures and nutrition of protein in cool-season adapted CDC chickpeas; (2) Characterize macro-molecular structure features of cool-season adapted CDC chickpeas and their genotypic impact on nutrient profile, fractionation, bioenergy values and biodegradation function in comparison with CDC barley kernel. Macromolecular structures determination was carried out using molecular vibrational spectroscopy-ATR-FTIR. Results showed that with vibrational molecular spectroscopy, the macromolecular spectral characteristics could be revealed among the varieties and between types of CDC developed grain (Chickpea vs CDC barley). The molecular spectral characteristics had significant relationship (P < 0.05) with carbohydrate profiles, sub-fractions and degradation, bypassed, total digestible carbohydrate and protein. Multiple regression with model nutrient variable selection study showed that protein and carbohydrate-related macro-molecular structural parameters were associated with nutrient profiles and degradation characteristics. The results indicated that there was an interactive association between macro-molecular structures and nutrition of protein in cool-season chickpeas.

Tutorial on the instrumentation of sum frequency generation vibrational spectroscopy: Using a Ti:sapphire based system as an example

Sum frequency generation vibrational spectroscopy (SFG-VS) is an intrinsically surface-selective vibrational spectroscopic technique based on the second-order nonlinear optical process. Since its birth in the 1980s, SFG-VS has been used to solve interfacial structure and dynamics in a variety of research fields including chemistry, physics, materials sciences, biological sciences, environmental sciences, etc. Better understanding of SFG-VS instrumentation is no doubt an essential step to master this sophisticated technique. To address this need, here we will present a Tutorial with respect to the classification, setup layout, construction, operation, and data processing about SFG-VS. We will focus on the steady state Ti:sapphire based broad bandwidth SFG-VS system and use it as an example. We hope this Tutorial is beneficial for newcomers to the SFG-VS field and for people who are interested in using SFG-VS technique in their research.

Survey on Adsorption of Low Molecular Weight Compounds in Cu-BTC Metal-Organic Framework: Experimental Results and Thermodynamic Modeling.

This contribution aims at providing a critical overview of experimental results for the sorption of low molecular weight compounds in the Cu-BTC Metal–Organic Framework (MOF) and of their interpretation using available and new, specifically developed, theoretical approaches. First, a literature review of experimental results for the sorption of gases and vapors is presented, with particular focus on the results obtained from vibrational spectroscopy techniques. Then, an overview of theoretical models available in the literature is presented starting from semiempirical theoretical approaches suitable to interpret the adsorption thermodynamics of gases and vapors in Cu-BTC. A more detailed description is provided of a recently proposed Lattice Fluid approach, the Rigid Adsorbent Lattice Fluid (RALF) model. In addition, to deal with the cases where specific self- and cross-interactions (e.g., H-bonding, Lewis acid/Lewis base interactions) play a role, a modification of the RALF model, i.e., the RALFHB model, is introduced here for the first time. An extension of both RALF and RALFHB is also presented to cope with the cases in which the heterogeneity of the rigid adsorbent displaying a different kind of adsorbent cages is of relevance, as it occurs for the adsorption of some low molecular weight substances in Cu-BTC MOF.

Simply Prepared Magnesium Vanadium Oxides as Cathode Materials for Rechargeable Aqueous Magnesium Ion Batteries.

Vanadium-oxide-based materials exist with various vanadium oxidation states having rich chemistry and ability to form layered structures. These properties make them suitable for different applications, including energy conversion and storage. Magnesium vanadium oxide materials obtained using simple preparation route were studied as potential cathodes for rechargeable aqueous magnesium ion batteries. Structural characterization of the synthesized materials was performed using XRD and vibrational spectroscopy techniques (FTIR and Raman spectroscopy). Electrochemical behavior of the materials, observed by cyclic voltammetry, was further explained by BVS calculations. Sluggish Mg2+ ion kinetics in MgV2O6 was shown as a result of poor electronic and ionic wiring. Complex redox behavior of the studied materials is dependent on phase composition and metal ion inserted/deinserted into/from the material. Among the studied magnesium vanadium oxides, the multiphase oxide systems exhibited better Mg2+ insertion/deinsertion performances than the single-phase ones. Carbon addition was found to be an effective dual strategy for enhancing the charge storage behavior of MgV2O6.