Electrochemical Characterization Research Articles

Synergistic effect of NASICON Na3V2(PO4)2F3 and 2D MXene for high-performance symmetric Sodium-ion batteries

Sodium fluorophosphate-based Na3V2(PO4)2F3 (NVPF) cathode materials have been widely analyzed in Sodium-ion batteries (SIB) owing to their high energy density and high working voltage. However, the low electronic conductivity of NVPF is a factor hindering their efficient use. To enhance the electronic conductivity of NVPF, in this work, a porous Na3V2(PO4)2F3 and a 2D Ti3C2-based MXene nanocomposite was synthesized using a facile sol-gel method. The NVPF, with the presence of two active redox couples, is a suitable choice for symmetric batteries. The NVPF + 2D MXene nanocomposite was analyzed for its structural and thermal characteristics, and a symmetric cell prepared from them was investigated for its electrochemical characteristics. Structural analysis of the materials developed indicates that the MXene addition has not altered the crystal structure of the NVPF. A remarkable improvement in the electrochemical performance of NVPF in the sodium symmetric cell is noticed, as indicated by its high specific discharge capacity of 92mAhg-1 at 1C for the MXene-incorporated composite structures. This improvement in electrochemical behaviour is confirmed in the rate capability curves, GCD curves, and GITT curves. The diffusion coefficient values obtained from GITT analysis showed improved kinetics in the synthesized material due to the MXene incorporation. The calculated values of the diffusion coefficient of Na+confirms the accelerated kinetics of Na+ ion migration during the intercalation/de-intercalation process in the MXene 5wt% nanocomposites, with a value of 9.57 × 10–9 cm2s-1 when compared to 4. 14 × 10–9 cm2s-1 for the pristine sample.

Electrochemical study of an enhanced platform by electrochemical synthesis of three-dimensional polyaniline nanofibers/reduced graphene oxide thin films for diverse applications

This work reports the electrochemical fabrication of thin films comprising polyaniline nanofibers (PANI) in conjunction with graphene oxide (GO) and reduced graphene oxide (rGO) on ITO substrate, along with examining the electrochemical properties, with a focus on the influence of the substrate and electrolyte in the electrodeposition methods. The study explores the electrochemical characteristics of these thin films and establishes a flexible framework for their application in diverse sectors such as sensors, supercapacitors, and electronic devices. It analyzes the impact of the substrate and electrolyte in electrodeposition techniques. The effects were studied using techniques such as cyclic voltammetry and chronoamperometry. The fabrication process of PANI/GO and PANI/rGO thin films involved the integration of rGO within PANI via electropolymerization, conducted under sulfuric acid. GO was synthesized by modifying the well-known Hummers’ method and characterized by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). SEM showed the diameters of the formed PANI were between 40 and 150 nm, which helped to intertwine the rGO nanosheets with PANI nanofibers to form thin films. The electrochemical behavior of the PANI/rGO thin films was examined using cyclic voltammetry (CV) and chronoamperometry in different electrolytes, including sulfuric acid (H₂SO₄) and potassium nitrate (KNO₃). The CV profiles exhibited distinct oxidation and reduction peaks, with variations in the voltammogram morphology attributed to the nature of the electrolyte and the substrate employed during the electrodeposition process. These results highlight the critical role of both the substrate and electrolyte in governing the electrochemical performance of PANI/rGO thin films. The findings from this study demonstrate a versatile approach for the fabrication of PANI/graphene-based thin films with tunable electrochemical properties, and such a strategy has great application to fabricating other thin film composites for supercapacitors or other control source frameworks requiring enhanced charge storage and electrochemical responsiveness.

Effects of ultrasonic treatment and current pulse frequency on properties of micro-arc oxidation coating on Mg alloy LAZ931

To enhance corrosion resistance of magnesium-lithium (Mg-Li) alloy LAZ931 in corrosive environments, a micro-arc oxidation (MAO) based surface treatment was carried out under a unipolar pulsed power supply. Effects of ultrasonic treatment and current pulse frequency on the performance of MAO coatings were investigated using scanning electron microscopy, electrochemical characterization, and friction wear tests. Results demonstrate that ultrasonic treatment greatly reduced the number density of micro-defects in the resulting MAO coatings and improved their overall performance. Corrosion and wear resistance of the MAO coating increased when current pulse frequency increased from 400 to 2000 Hz. Those findings are beneficial for improving the performance of MAO on Mg-Li alloys through optimizing the processing parameters.

Sustainable hybrid nanocomposites of Au nanoparticles modified carboxylated nanographene oxide: Electrochemical characterisation and estrone detection

Sustainable hybrid nanocomposites of Au nanoparticles modified carboxylated nanographene oxide: Electrochemical characterisation and estrone detection

"Synergistic Hybridization of Mn-MOF@rGO and Ti3C2 for High-Performance Supercapattery Devices and Hydrogen Evolution Reaction"

The burgeoning interest in two-dimensional (2D) materials stems from their heightened storage capacity and superior conductivity. Here, we synthesized a metal-organic framework of manganese (Mn-MOF) and introduced reduced graphene oxide (rGO) doping into this heterostructure using a hydrothermal method. Subsequently, Ti3C2Tx MXene was prepared via a template method. The Mn-MOF@rGO was then combined with Ti3C2Tx MXene in a 50/50 wt% ratio using hydrothermal techniques, and their structural and electrochemical characteristics were evaluated. In 3-electrode measurements, the MnMOF@rGO/Ti3C2Tx composite conductor exhibited a precise capacity of 2645 C/g (5.29 C/cm3) at 1.8 A/g. Furthermore, a hybrid device termed a supercapattery was fabricated employing MnMOF@rGO/Ti3C2Tx along with activated carbon (AC) composite electrodes, demonstrating remarkable energy density of 67 Wh/kg and an impressive power density of 880 W/kg. After 8,000 cycles, the electrode exhibited 84% capacity retention and maintained 92% columbic efficiency. In the hydrogen evolution reaction (HER), the MnMOF@rGO/Ti3C2Tx composite displayed a minimal Tafel slope of 54.65 mV/dec. These two-dimensional composite electrodes offer novel avenues for the advancement of high-performance energy device.

Machine Learning for Battery Quality Classification and Lifetime Prediction Using Formation Data

Accurate classification of battery quality and prediction of battery lifetime before leaving the factory would bring economic and safety benefits. Here, we propose a data-driven approach with machine learning to classify the battery quality and predict the battery lifetime before usage only using formation data. We extract three classes of features from the raw formation data, considering the statistical aspects, differential analysis, and electrochemical characteristics. The correlation between over 100 extracted features and the battery lifetime is analysed based on the ageing mechanisms. Machine learning models are developed to classify battery quality and predict battery lifetime by features with a high correlation with battery ageing. The validation results show that the quality classification model achieved accuracies of 89.74% and 89.47% for the batteries aged at 25°C and 45°C, respectively. Moreover, the lifetime prediction model is able to predict the battery end-of-life with mean percentage errors of 6.50% and 5.45% for the batteries aged at 25°C and 45°C, respectively. This work highlights the potential of battery formation data from production lines in quality classification and lifetime prediction.

DFT and AIMD studies of SnFe2O4 as a promising anode for Li-ion batteries

Tin ferrite (SnFe2O4) is considered as a perspective lithium ion battery anode, owing to its low cost, large theoretical capacity, low toxicity, structural stability, and easy synthesis method. Prior research has been done on the performance of lithium storage in SnFe2O4. However, the electrochemical processes that take place during the lithiation-delithiation cycle of LIBs have not been explained in depth yet. In order to understand the discharge mechanism in the LixSnFe2O4 anode (x = 0 to 2), we systematically investigated its electrochemical characteristics, structural and electronic properties, average formation energies, open-circuit voltages, diffusion coefficient, and volume expansion using density functional theory. According to our calculations, an increase in Li concentration x up to 1.125 leads to enhanced stability of the LixSnFe2O4 systems. During this process, Li+ ions prefer to be intercalated at the octahedral 16c sites, inducing the displacement of Sn2+ ions from tetrahedral sites 8a to 16c and 48f sites. However, for 1.125 < x < 2, lithium ions tend to occupy the less stable sites 48f , which reduces the stability of LixSnFe2O4 systems.Additionally, the calculated lithium intercalation voltage for full lithiation Li1.125SnFe2O4 is equal to 1.5 V, and the distortion of the LixSnFe2O4 system occurs at a voltage of 0.75 V, which is in well agreement with experimental results. The Li-coefficient diffusion on SnFe2O4 at 300 K is calculated by ab initio molecular dynamic simulation and equal to 8.22 × 10−8 cm2/s, which indicates the excellent mobility of Li ions in SnFe2O4. Considering all these results, we can suggest SnFe2O4 as a promising negative electrode material for lithium-ion batteries.

Synergistic effect of P2, O3 phase on biphasic layered oxide with enhanced electrochemical performance for sodium storage

Oxides with a layered structure are regarded as prospective candidates for use as cathodes in the next generation of sodium ion batteries. These materials, which exhibit a P2 structure and O3 structure, possess distinctive advantages that give rise to disparate electrochemical performance. Herein, a thermodynamically and kinetically stable P2/O3 biphasic layered oxide with a chemical formula of K0.05Na0.8Ni0.5Mn0.5O2 is synthesized using a simplistic high temperature solid-state method. P2 phase enhances the structural stability of the material, while O3 phase provides additional sodium storage sites, thereby increasing the material’s capacity. The joint action of the two phases results in an improvement in the electrochemical characteristics. Moreover, the Ni-Mn-based layered oxide is enhanced by Fe-substitution, which effectively mitigates the Jahn-Teller effect caused by Mn3+, thereby improving the comprehensive electrochemical performance of the cathode. The Fe-doped specimen offers 102.8 mAh g−1 as the initial reversible discharge capacity under a high current density of 200 mA g−1, and a high capacity retention amounting to 83.17 % is attained after 200 cycles. In addition, the structural development of the P2/O3 biphasic sample during Na+ extraction/insertion was elucidated by in situ XRD. This paper employs the advantages of P2 and O3 phases to augment material electrochemical characteristics and verifies the possibility of the P2/O3 biphasic structure by density functional theory (DFT) calculations, providing new ideas for biphasic sodium ion battery cathode materials.

Evaluation of 14-(p-tolyl)-14H-dibenzo[a,j]xanthene as a highly efficient organic corrosion inhibitor for mild steel in 1 M HCl: Electrochemical, theoretical, and surface characterization

Corrosion of mild steel, particularly in acidic environments such as hydrochloric acid (HCl), remains a critical issue due to its impact on material durability, economic costs, and safety concerns. This study introduces 14-(p-tolyl)-14H-dibenzo[a,j]xanthene (ZM5), a novel and highly effective organic corrosion inhibitor, to mitigate this challenge. Employing advanced electrochemical techniques: electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP), we evaluated ZM5’s performance in a 1 M HCl solution, revealing an impressive inhibition efficiency of 94.7 %. Surface characterization using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) further confirmed the formation of a robust protective film on the steel surface, shedding light on ZM5’s adsorption mechanisms. Complementing the experimental findings, Density Functional Theory (DFT) simulations provided theoretical insights into the anti-corrosion mechanism of ZM5, aligning well with observed results. These findings underscore ZM5's potential as a highly promising corrosion inhibitor for industrial applications, effectively enhancing the corrosion resistance of mild steel in aggressive environments.

Preparation and application of ZnO-Ecoflex composite sensors for lactate detection during physical training

This study presents the development of a flexible ZnO-Ecoflex composite sensor for noninvasive lactate detection during physical training. ZnO nanostructures with an average diameter of 50 nm were synthesized and incorporated into an Ecoflex matrix. The optimized sensor, featuring 15 wt% ZnO loading, demonstrated high sensitivity (22.7 μA·mM⁻¹·cm⁻²) and a low detection limit (2.3 μM). The composite displayed impressive mechanical characteristics, showcasing a tensile strength of 1.3 MPa and an elongation at fracture of 390%. Electrochemical characterization revealed a diffusion-controlled electron transfer process and rapid response time of 5 seconds. The sensor showed minimal interference from common sweat components (&lt;3.2% relative response) and maintained consistent performance under various bending conditions (RSD 3.2%). Real-time monitoring during a 30-minute jogging session demonstrated the sensor's ability to capture dynamic changes in sweat lactate levels. This research contributes to the development of wearable biosensors for continuous lactate monitoring in sports and exercise science, offering potential for personalized training optimization.

Sensitive electrochemical detection of dopamine using CuCo2O4/graphene quantum dots-modified carbon paste electrode

This research investigates the fabrication and electrochemical characterization of a modified graphene paste electrode (MCPE) incorporating CuCo2O4 bimetallic oxide and its composite with graphene quantum dots (GQDs) for dopamine detection. The CuCo2O4 was synthesized via a hydrothermal method. The oxidation–reduction behavior of dopamine on the GQD/CuCo2O4/CPE indicates a quasi-reversible electrochemical reaction with an absorption-controlled electron transfer process and the kinetics of the catalytic reaction followed pseudo first-order. The average value of the electron transfer rate constant for GQD/CuCo2O4 was observed to be 0.047 s−1. Characterization of the obtained materials was performed using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Subsequently, under optimized conditions, cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS) were employed to evaluate the dopamine sensing performance of the MCPEs. The GQD/CuCo2O4 composite electrode exhibited a lower detection limit (0.004 μM) and quantification limit (0.013 μM) for DA compared to the CuCo2O4 electrode (0.0088 μM and 0.030 μM, respectively). The GQD/CuCo2O4 nanocomposite showed better sensitivity (33.0 mA/mM) than CuCo2O4 (17.9 mA/mM) due to the superior conducting nature of GQD. Finally, the applicability of the GQD/CuCo2O4-based MCPE was demonstrated by measuring DA in real samples.

Potential application of room temperature synthesized MIL-100(Fe) in enhancing methane production in microbial electrolysis Cells-Anaerobic digestion treating Protein-Rich wastewater

Microbial electrolysis cell-anaerobic digestion (MEC-AD) is an emerging technology for methane production. However, low substrate degradation efficiency remains a challenge when processing protein substrates. This study developed a MIL-100(Fe) carbon cloth anode to enhance methane production and substrate degradation in MEC-AD. The effects of MIL-100(Fe) prepared under hydrothermal (H-MIL-100(Fe)) and room temperature conditions (R-MIL-100(Fe)) were compared. Results indicated that H-MIL-100(Fe) and R-MIL-100(Fe) increased cumulative methane production by 16.01% and 14.99%, respectively compared to normal cloth, each influencing methane production through distinct mechanisms. Electrochemical characterization showed that H-MIL-100(Fe) enhanced the electrochemical performance more significantly due to the enrichment of Geotalea, with the oxidation current improved by 7.39-fold (R-MIL-100(Fe) increased it by only 2.95-fold) to promote growth of Methanobacterium. Metagenomic analysis revealed that R-MIL-100(Fe) tended to metabolize amino acids into methane rather than support cellular life activities, indicating its practicality under limited substrate concentration. In summary, R-MIL-100(Fe) shows greater potential for application due to its mild synthesis conditions and advantages in treating complex substrates.

Six element high-entropy Prussian blue analogue cathode enabling high cycle stability for sodium-ion batteries

Prussian blue analogues (PBA) are promising cathode materials for sodium-ion batteries. However, the cycle life of PBA is limited due to its structure instability during cycling. Here, we successfully introduce six transition metals into N coordination site to increase the configurational entropy, significantly improving the structure stability and cycle life of PBA cathode materials. Electrochemical characterization methods are used to compare the behavior of hexa-, penta-, quadr-, and tri-metal PBA, exhibiting the characteristic of performance increasing with entropy. Time-resolved in situ X-ray diffraction confirms the “quasi-zero-strain” structure of H-PBA during desodiation/sodiation process. X-ray absorption spectroscopy and density functional theory calculations reveal that Mn, Fe, Co and Cu contribute the high capacity of H-PBA, while Ni and Zn stabilize the structure. The strategy will inspire new ideas in designing long life cathode materials with high capacity for sodium-ion batteries.

Unraveling the Complex Temperature-Dependent Performance and Degradation of Li-Ion Batteries with Silicon-Graphite Composite Anodes

Competing effects of graphite and Si result in a complex temperature dependent performance and degradation of Li-ion batteries with Si-graphite composite anodes. This study examines the influence of varying the Si content (0 to 20.8 wt%) in Si-graphite composite anodes with consistent areal capacity and N/P ratio in full cells containing NMC622 cathodes. One hundred pilot-scale double-layer pouch cells were built and cycle aged in the temperature range from −10 to 55 °C. Electrochemical characterization demonstrated that increasing Si contents enhance capacity and mitigate internal resistance at low temperatures. On the other hand, high Si contents decrease charge-discharge energy efficiency and cycle life, particularly at elevated temperatures. Post-mortem analysis of aged electrodes, including physico-chemical characterization (scanning electron microscopy, energy-dispersive X-ray analysis, thickness measurements) and cell reconstruction revealed significant solid electrolyte interphase growth and increased loss of active material in anodes with high Si content. The optimum temperature for longest cycle life as derived from Arrhenius plots decreased from 30 °C for graphite anodes to 10 °C for cells with moderate Si content up to 5.8 wt%. These findings allow the design of optimized cells by balancing the Si content versus operating temperature in order to achieve lowest cell aging.

Quinone Quest: Unraveling electrochemical performance in quinone-anchored 3D graphene architectures for high-energy supercapacitors

In the pursuit of advancing energy storage technologies, the exploration of novel electrode materials for supercapacitors, specifically organic materials, has garnered significant attention. This work delves into the electrochemical performance of quinone-anchored three-dimensional (3D) graphene (3DG) architectures as potential electrode materials for high-energy supercapacitors, focusing on elucidating the influence of different quinone types including 1,4-naphthoquinone (NQ), anthraquinone (AQ), duraquinone (DQ), p-benzoquinone (BQ), 2,5-dimethyl-1,4-benzoquinone (DMBQ), and sodium anthraquinone-2-sulfonate (SAQS). To that end, various quinone-anchored three-dimensional graphene (Q_3DG) architectures were synthesized via a chemical reduction-induced self-assembly technique in the presence of l-ascorbic acid, a green reducing agent. The physicochemical characterizations confirmed the successful incorporation of quinones to the carbon structure, without the presence of any impurities. Different interaction mechanisms between graphene oxide (GO) and quinone molecules during the synthesis led to different surface morphologies, which affected their electrochemical behavior. The 3-electrode electrochemical characterizations in 1.0 M Na2SO4 electrolyte revealed that all Q_3DG structures exhibited superior electrochemical performance compared to GO, as well as to a Bare_3DG sample synthesized without quinone molecules. NQ anchored 3DG (NQ_3DG) network yielded the highest specific capacitance value of 386.3 F.g−1 at 10 mV.s−1, which was almost 50 times larger than that of Bare_3DG. The findings not only shed light on the fundamental mechanisms governing charge storage and transfer within these unique architectures but also provide valuable insights for the rational and green design of next-generation organic electrode-based supercapacitors with enhanced energy storage capabilities.

Electrochemical characterization of Bi3Ru3O11 – 40 wt% Bi1.6Er0.4O3 as an EOG electrode material

This paper reports on the study of the electrochemical behavior of porous Bi3Ru3O11 – 40 wt% Bi1.6Er0.4O3 electrodes on a Bi2O3 – 10 wt% Bi24B2O39 electrolyte in a symmetric cell configuration by impedance spectroscopy. The dependence of the area specific resistance (ASR) for electrode polarization on the partial pressure of oxygen replaced from PO2−1/2 to PO2−3/4 with decreasing thickness of the layer, which inhibited wetting. This indicates a change in the rate-limiting oxidation-reduction reactions of oxygen. It is assumed that the dissociation of adsorbed oxygen molecules on the active catalytic centers of the triple phase boundary (TPB) is the limiting stage of a surface oxygen exchange, and with a decrease in the layer thickness, additional difficulty in the transfer of gaseous oxygen molecules from the gas phase to these active catalytic centers is observed.

Fabrication of novel S-type In2S3/Ag2S heterostructures with superior photocatalytic and electrochemical characteristics for remediation of organic contaminants in water

In the present report, In2S3/Ag2S heterojunctions were created hydrothermally and characterized for their crystalline structure, morphology, composition, optical characteristics, charges reunification and property of charge by standard analytical techniques. Synthesized nanomaterials were utilized for the decontamination of organic pollutants such as Rhodamine B (RhB) dye and antibiotic ciprofloxacin (CP) by using visible light radiance. Calculated photocatalytic removal efficacy for RhB and CP over In2S3/Ag2S nanocomposite was 99.95 % in 40 min and 99.49 % in 140 min respectively which is 1.98 and 1.21 times greater than In2S3 alone. Maximum removal efficiency was achieved for In2S3/Ag2S (3 wt%) composition. The enhanced activity is attributed to the greater absorption of visible light and construction of S-type heterojunction which are more efficient for light induced charge separation and therefore decrease the reunification of hole-electron carriers. Density functional theory (DFT) analysis also supported that the nanocomposite is energetically favorable, stable and show significantly electronic and photocatalytic properties. In2S3/Ag2S (3 wt%) nanocomposite achieved excellent photocatalytic stability towards the removal of RhB and CP even after five runs. In2S3/Ag2S (3 wt%) nanocomposites showed maximum photocatalytic activity in acidic medium. Effect of trapping agents towards removal of CP and RhB were conducted and results showed that.O2− radical play dominant role as active species in comparison to ⋅OH radical and holes. Plausible mechanism of transfer of charge in In2S3/Ag2S and removal of pollutants is also represented. Owing to their unique features, novel In2S3/Ag2S heterojunctions exhibits as an exceptionally effective photocatalyst for removal of pollutants and it would display the promising utilization towards wastewater treatment.

Impact of ultrasonic treatment duration on the microstructure and electrochemical performance of NiZnCo2O4 electrode materials for supercapacitors

This work investigates the impact of different ultrasonic treatment durations on the synthesis and electrochemical performance of NiZnCo2O4 (NZC) supercapacitor electrodes. Optimizing treatment to 20 min resulted in a uniform, compact NiZnCo2O4 layer with improved nanostructures, which increased the surface area and active sites for electrochemical reactions. X-ray diffraction (XRD) confirmed successful NiZnCo2O4 synthesis, revealing distinct crystalline phases of NiO, ZnCo2O4, and Co3O4, with improved crystallinity. Electrochemical tests, conducted using a 1.0 M KOH electrolyte, demonstrated that the NZC-2 electrode treated for 20 min achieved the highest 5.678 F/cm3 volumetric capacitance at 0.5 mA/cm2 current density along with 70.5 Wh/kg an energy density at 260 W/kg power density. The galvanostatic charge-discharge and cyclic voltammetry tests revealed that NZC-2 maintained superior charge-discharge efficiency, showing the longest discharge time at 1 mA/cm². Electrochemical impedance spectroscopy (EIS) measurements demonstrated that NZC-2 exhibited the lowest total impedance, thereby enhancing ion transport efficiency. The NZC-2/AC asymmetric supercapacitor showed excellent long-term stability, retaining 64.2% of its capacity after 20,000 charge-discharge cycles. It successfully powered a 1.2 V small fan, demonstrating its practical applicability. The results highlight the crucial importance of ultrasonic treatment in greatly improving the structural and electrochemical characteristics of NiZnCo2O4 electrodes, which opens up possibilities for the advancement of high-performance supercapacitors.

Harnessing the Dual photocatalytic and electrochemical capabilities of pure and Ni-Doped MgO nanostructures for diclofenac detection

A pure MgO and MgO doped with 2, 4, 6, and 8 mol% of NiO nanoparticles (NPs) were preparedusing the solution combustion technique. Several spectral techniques were used to characterize the synthesized NPs. The XRD analysis revealed the average particle size of the MgO-infused NiO nanomaterial was ranging between 16.28 and 71.26 nm. A distinct plate-like or slice-like quality to the morphology was observed during the SEM analysis. The average energy gap (Eg) value of NiO doped MgO NPs (Ni:MgO NPs) was found to be 4.29 eV. The prepared Ni:MgO NPs exhibited good electrochemical characteristics. These nanoparticles were successfully used for the detection of diclofenac molecule using the modified graphite electrodes with 0.1 N HCl as an electrolyte. The results shows an oxidation peak at 0.19 V before diclofenac was added, later it is migrated significantly towards the positive potential (0.07 V) after diclofenac was added. The pure MgO and MgO doped with 2, 4, 6, and 8 mol% of NiO were used for further studies of photodecolorization of Drimaren blue dye under UV/sunlight irradiation. The reduction in the peak intensity of Drimaren Blue dye was observed. MgO exhibited an enhanced photocatalytic activity of 68.7 % and MgO:NiO exhibited 81.9 %. According to these studies, the 6 mol% NiO doped MgO is a viable choice for the wastewater treatment and electrochemical detection of diclofenac.

Structure-Driven Performance Enhancement in Palladium-Graphene Oxide Catalysts for Electrochemical Hydrogen Evolution.

Graphene oxide (GO) has recently gained significant attention in electrocatalysis as a promising electrode material owing to its unique physiochemical properties such as enhanced electron transfers due to a conjugated π-electron system, high surface area, and stable support for loading electroactive species, including metal nanoparticles. However, only a few studies have been directed toward the structural characteristics of GO, elaborating on the roles of oxygen-containing functional groups, the presence of defects, interlayer spacing between the layered structure, and nonuniformity in the carbon skeleton along with their influence on electrochemical performance. In this work, we aim to understand these properties in various GO materials derived from different graphitic sources. Both physiochemical and electrochemical characterization were employed to correlate the above-mentioned features and explore the effect of the location of the palladium nanoparticles (Pd NPs) on various GO supports for the hydrogen evolution reaction (HER). The interaction of the functional groups has a crucial role in the Pd dispersion and its electrochemical performance. Among the different GO samples, Pd supported on GO derived from graphene nanoplate (GNP), Pd/GO-GNP, exhibits superior HER performance; this could be attributed to the optimal balance among particle size, defect density, less in-plane functionalities, and higher electrochemical surface area. This study, thus, helps to identify the optimal conditions that lead to the best performance of Pd-loaded GO, contributing to the design of more effective HER electrocatalysts.