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Due to over depletion of fossil fuels, researchers started to find hydrogen energy to compete with the energy demands. Bi 2 WO 6 and Ni (5% and 10%) doped Bi 2 WO 6 were prepared via hydrothermal route. Structural confirmation of undoped and doped Bi 2 WO 6 nanostructures was estimated by using standard characterization studies. The nanoflake and nanoneedle like morphology of undoped and Ni doped Bi 2 WO 6 was confirmed in nanoscale range. The highest OER activity was achieved for 10% Ni doped Bi 2 WO 6 nanostructure electrode with the excellent current density of 272 mA/g with overpotential of 242 mV in the fabricated three electrode half cell set up. The higher electron transport offered by Ni ions to Bi 2 WO 6 host has been reported with the electrochemical mechanism. Hence, the unusual robust electrodes for electrochemical potential applications by tuning its property via suitable foreign ion dopant could be the great beginning of this recent year research. In such a way, this work would be the better way of swapping of nobel metal catalysts for electrochemical OER activity. • Bare and Ni doped Bi 2 WO 6 morphological evolution has been explored. • 10% Ni doped Bi 2 WO 6 revealed excellent OER activity of 272 mA/g at 10 mV/s. • Appreciably low overpotential of 242 mV has been achieved for 10% Ni doped Bi 2 WO 6. • Explored higher electron transport offered by Ni ions to Bi 2 WO 6 host. • Outstanding stability over 24 h with high conductivity was achieved. [ABSTRACT FROM AUTHOR]

New attractive advances in electrode preparation for supercapacitor applications with rGO based composite materials are eye-catching attention of researchers. Cobalt oxide is considered as an effective electrode for full cell fabrication due to its high specific capacitance. Cost effective solvothermal method was used to prepare pristine Co 3 O 4 nanorods, NiCo 2 O 4 nanorods and NiCo 2 O 4 /rGO urchin like nanocilia structure composite materials. The complete electrochemical studies were used to check the obtained product electrochemical activity. The high specific capacitance values are obtained for NiCo 2 O 4 /rGO urchin like nanocilia composite electrode material which leads to design a full cell and make use as practical applications with illuminating red, green, blue LED source. The capacitive retention of 92.28% even after 5000 cycles achieved in GCD cyclic performance at a high current density implies its excellent stability. Image 1 [ABSTRACT FROM AUTHOR]

• Involvement of Ca in DyMnO 3 parent matrix results in increased specific capacitance. • Novel perovskite composites for usage in battery-type electrodes in supercapacitor applications. • Battery-type electrode performance of the composite made into a device showed capacity retention of 76% The Multifaceted properties of nanostructured rare earth perovskite manganite oxides have attracted much attention specifically for their applications in energy storage systems. In the present work, synthesis and physiochemical properties of calcium-substituted dysprosium perovskite manganite oxide nanocomposites and their potential applications as supercapacitors are examined. The perovskite structure and morphology of the designed nanocomposites are affirmed by the different analytical tools, including XRD, SEM, and TEM analysis. The structural analysis by XRD indicates the presence of DyMnO 3 perovskite phase with additional peaks of Dy 2 O 3 phase. The percentage of Dy 2 O 3 is gradually reduced with higher Ca substitution, from about 16% to 7%. The Halder-Wagner method indicates an increase of the microstrain and a decrease in crystallite size with the rise of Ca substitution. From Tauc's plot derived from DRS analysis, a slight increase in the band gap with the increase in Ca substitution is observed (2.55–2.62 eV). The surface elemental compositions and the valence states of individual elements analyzed using XPS analysis evidence the presence of Dy, Ca, Mn, and O. BET adsorption study indicates an increase in pore size, surface area, and pore volume with increasing Ca substitution concentration. When employed as a supercapacitor electrode material, Calcium-blend DyMnO 3 nanocompositeexhibits battery type behavior. This material shows a higher specific capacitance (capacity) of 531 Fg−1 (319.9 Cg−1) with comparatively low charge transfer resistance and better cyclic stability. We have assembled an asymmetric supercapacitor device using our prepared sample exhibiting energy density of 36.16 Wh/kg with better cyclic stability. This work provides new insights for designing future Dy 2 O 3 based supercapacitors. [ABSTRACT FROM AUTHOR]

• Sm-MOF/rGO/PANI was synthesized via in situ oxidative polymerization. • Redox-active sites enabled solitary-MOFs based catalyzed by ternary composite using Sm-MOF/rGO/PANI are utilized for high-performance supercapacitors due to their high surface tunability. • Sm-MOF/rGO/PANI can be used as an electrode material for high-performance supercapacitors due to their high surface tunability. • The composite shows a high specific capacitance of 1935.6 f g-1 in a three-electrode setup. • The specific power and energy was calculated to be 581 Wh Kg−1 and 59.3 W Kg−1. In recent years, scientists have been paying a lot of attention to metal-organic frameworks, often known as MOFs, as a possible material for use as electrodes in supercapacitors. MOFs are capable of functioning as high-quality pseudocapacitors because of their crystalline structure, which enhances the specific surface area and provide mechanical support for composite materials. The objective of this study is to synthesize an electrode material that can be used as supercapacitors by synthesizing Sm-MOF and then combining it with reduced graphene oxide (rGO) and polyaniline (PANI) to make a hybrid material. Here, the effect of incorporation of PANI and rGO in Sm-MOF is investigated, and its application as a supercapacitor is examined. Due to the high surface area and pore size, Sm-MOF/rGO/PANI material exhibits high specific capacitance. The computed specific capacitance of the composite Sm-MOF/rGO/PANI material is 1935.6 F g−1 when subjected to a current density of 1 A g−1. The Sm-MOF/rGO/PANI device is fabricated and exhibits a specific capacitance of 218 F g−1. The specific power and energy are calculated to be 59.3 Wh kg−1 and 581 W kg−1, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

• Cr 2 CT x MXene is synthesized via chemical etching using HF acid for 30 min. • The prolonged ultrasonication is used for preparing bifeo 3 /Cr 2 CT x MXene composite. • Electrochemical properties are evaluated towards HER and supercapacitor application. • BiFeO 3 /Cr 2 CT x MXene achieves η 10 of 128 mV and 53.3 mV dec−1 as the tafel slope. • Specific capacitance of 1678 f g −1 is achieved for bifeo 3 /Cr 2 CT x MXene electrode with long term stability. A multifunctional hierarchical Bismuth ferrite/chromium carbide (BiFeO 3 /Cr 2 CT x) MXene has been employed as both electrode material for supercapacitors as well as an electrocatalyst for electrocatalytic water splitting. Here, a facile method is suggested for synthesizing Cr 2 CT x MXene from the chromium aluminum carbide (Cr 2 AlC) MAX Phase. X-ray diffraction studies, Scanning electron microscopy, and high-resolution transmission electron microscopy indicate that the aluminum atomic layers are removed from Cr 2 AlC MAX structure. The electrochemical test reveals that the BiFeO 3 /Cr 2 CT x MXene composite, which is produced with less Al 2 O 3 , performs well in the hydrogen evolution reaction (HER) with a low overpotential of 128 mV in 1 M potassium hydroxide. 53.3 mV dec−1, and 0.16 Ω cm−2, respectively, are the values of the calculated Tafel slope and charge transfer resistance. In a dielectrode electrolysis system, BiFeO 3 /Cr 2 CT x MXene electrode needs only 1.81 V of cell potential to provide 10 mA cm−2 with long-term stability. The specific capacity of 671.2 C g −1 at a current density of 1 A g −1 is obtained for BiFeO 3 /Cr 2 CT x MXene electrode with 90% capacitance retention after 3000 cycles. The potential use of BiFeO 3 /Cr 2 CT x MXene towards HER and supercapacitor application is demonstrated by this study, which offers a gentle path for the fabrication of Cr 2 CT x MXene composites for energy storage and HER applications. [Display omitted] [ABSTRACT FROM AUTHOR]

Supercapacitors are potential energy storage devices with a broad range of applications. In this study, we are investigating a bismuth ferrite/graphitic carbon nitride/N-doped graphene quantum dots composite as an electrode material for supercapacitor applications. XRD patterns of the composite exhibit the different crystalline phases of the individual component and confirm the rhombohedral structure of the composite. The wafer-like structure of bismuth ferrite is produced via hydrothermal technique supported on 2D structures viz. graphitic carbon nitride and N-doped graphene quantum dots. Compared to bismuth ferrite and bismuth ferrite/graphitic carbon nitride (g-CN) binary composite, the bismuth ferrite/g-CN/N-doped graphene quantum dots demonstrates a superior specific capacitance of 1472 F g−1 at 1 A g−1 current density. After 3000 charging-discharging cycles, the device maintains its cycling stability with 87% capacitance retention. A supercapacitor device is assembled utilizing bismuth ferrite/graphitic carbon nitride/N-doped graphene quantum dots and activated carbon as electrodes. This device shows a significantly improved performance with an energy density of 53.1 Wh kg−1 and a power density of 705.4 W kg−1. As a result, the composite electrode developed in this study is proved to be a potential electrode material for high-performance energy storage devices. [Display omitted] • BiFeO 3 /g-CN/N-doped graphene quantum dot is prepared via a two-step method. • Superior specific capacitance of 1472 F g−1 at 1 A g−1 was shown by the composite. • The material showed high level of capacity retention of 87% after 3000 cycles. • An energy density of 53.1 Wh kg−1 and specific power of 705.4 W kg−1 are exhibited. [ABSTRACT FROM AUTHOR]

[Display omitted] • Summarizing recent advances in the fabrication of stretchable supercapacitor. • The various experimental parameters, which used to design the stretchable electrode are summarized. • Various experimental approaches used to fabricate the stretchable supercapacitor are also discussed. • · Several structural designs of the stretchable electrodes with diverse electroactive materials are reviewed. • Challenges and future direction of stretchable supercapacitors were also discussed. In the modern phase of electricity and global connectivity, a supercapacitor plays an eye-catching role by overcoming the detrimental of capacitors and batteries. Imagining an advanced smartphone, a miniature, light-weight, flexible electronic device with good power and energy capability, large-scale stretchability, and self-healing property is one step ahead of becoming a reality in innovations. To facilitate the sustainable operation and ensure the reliability of the obtained electronic system, it is desirable to obtain satisfactory performance under certain conditions like bending, stretching, compressing, deforming and twisting, etc. However, multifunctional integrity remains a challenge in a single system. The stable and insistent output can only be possible by choosing the proper electrode design and material selection. This review discusses the recent trends in different categories of stretchable materials used for supercapacitor applications, various architectures influencing their stretchability, their mechanical properties like strain, pre-stretchability and healability, etc. and the usability of these stretchable materials in smart and wearable devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antimony revealed rhombohedral crystal structure formation with D 3 d 5 (R 3 ¯ m) space group situated on symmetry C 3v sites. • In-plane longitudinal vibration (110.67 cm−1; E g) and out of plane vibration (A 1g ; 147 cm−1) revealed pure antimony. • The solution resistance value of Sb-NMP is 1.67 Ω and good conductive in nature. • Pure Sb (1.96 Ω) and Sb-Ball (1.93 Ω) exhibited low solution resistance value. • Sb-NMP showed exceptional HER performance with high stability of 80% retention. Modern research focuses exclusively on the search for relatively inexpensive, highly efficient electrocatalytic materials for the electrocatalytic hydrogen production water splitting reactions. Antimony is a chemical element having four allotropes with three oxidation states. Antimony is a semi-metal with elemental antimony. Recently, elemental antimony (Sb) with an extensive light absorption was recognized as good electrocatalytic for hydrogen evolution reactions. This study focuses on preparation and characterization of antimony nanoparticles for hydrogen evolution activities as explored. We report the structural, optical, vibrational, electrochemical properties of the pristine antimony nanoparticles for efficient catalytic material for electrochemical water splitting applications. The prepared antimony nanoparticles revealed the rhombohedral crystal structure formation with D 3 d 5 (R 3 ¯ m) space group situated on symmetry C 3v sites. In Raman studies, the peak appeared at 110.67 cm−1 corresponds to in-plane longitudinal vibration (E g) and at 147 cm−1 for out of plane vibration (A 1g) for pure antimony. The synergic effect of NMP and ultrasonication yields highly homogeneous antimony nanoparticles as evidenced from morphological analysis. From electrochemical impedance analysis, the solution resistance value of Sb-NMP is 1.67 Ω, which was small in comparison to the pure Sb (1.96 Ω) and Sb-Ball (1.93 Ω) and exhibited the good conductive nature of Sb-NMP nanomaterials. From electrochemical HER analysis, we found that the Sb-NMP showed the low 246 mV@10 mA/cm2 overpotential with low 186 mV/dec Tafel slope value. Furthermore, the chronoamperometry study exposed that the electrocatalyst Sb-NMP delivered an exceptional HER performance with high stability of 80% retention for continuous three hours measurements. Therefore, this study may perhaps facilitate the growth of antimony nanoparticles which can be used as an HER catalysts for improving the electrocatalytic HER activity. [ABSTRACT FROM AUTHOR]

This paper reported the successful preparation and characterization of bio-activated carbon nanosheets (ACNSs) synthesized from tamarind (tamarind indicia) fruits shells (TFSs) by employing Chemical Vapor Deposition (CVD) tubular furnace. The preparation of pure ACNSs and also potassium hydroxide (KOH) activated carbon nanosheets (K-ACNSs) were made through a pyrolysis process with Argon (Ar) gas as an inert gas at 800 °C for 2h 30min, followed by further purifications of K-ACNSs. The scanning electron microscope (SEM) images of ACNSs and K-ACNSs explored with and without pores respectively. The SEM micrographs also explored 3D-porous microstructure sheets with thickness around 18–65 nm. Raman spectroscopy explored crystallinity, SP 2 order and graphitization at 1577–1589 cm−1. The major functional groups were also observed. The photoluminescence (PL) was analyzed for K-ACNSs materials and revealed carbon emission broad peak value at 521.3 nm. As prepared ACNSs and K-ACNSs active materials was applied for three-electrode materials of energy storage supercapacitor analysis of cyclic voltammeter for −0.4 – 0.15 V at scan rates of 10–100 mV/s. The electrochemical impedance spectroscopy (EIS) was performed with low Rct values of K-ACNSs as 0.65Ω when compared to pure ACNSs as 5.03Ω. Mainly, the galvanostatic charge-discharge test carried out in ACNSs and KCNSs materials was corresponded to 77 and 245.03 F/g respectively, with respect to 1 A/g current density. Finally, we promise that this reported novel tamarind bio-waste into conductive porous carbon nanosheets could develop future energy storage applications of biomass-derived carbons. • New technique to prepare 3D pores activated carbon nanosheets were demonstrated. • Carbonization/pyrolysis of tamarind shells in argon (Ar) leads graphitic carbon. • ACNSs specific capacitance observed was 77 F/g at 1A/g. • KCNSs specific capacitance observed was 245.07 F/g at 1A/g. [ABSTRACT FROM AUTHOR]

To attain elevated class MXene (Ti 3 C 2 Tx) through a homemade kitchen blender method, high shear mechanical exfoliation is highly required for the efficient delimitations of MXene nanosheets from bulk MAX (Ti 3 AlC 2). We examine large-scale industrial productions of the MXene nanosheets, where combing the predicted 2D materials using a blender is a first-time novel approach with the delaminating solvent as a dimethyl sulfoxide (DMSO). And also manually created layered MXene systems (handmade) delaminating MXene sheets (MX-H) was furthermore employed for environmental dye-degradations applications. The materials characterizations was done for both the bulk MAX, MX-H and the MX-B. Additionally, the surface morphological studies like scanning electron microscopy (SEM) were investigated for both MX-H and MX-B as-prepared samples. SEM images indicated the high shear blander technique formations highly expanded/delaminated MXene (Ti 3 C 2 Tx) nanosheets compared to MX-H samples. FTIR technique is employed to identify –OH, C–H, C–O stretching vibrations for both materials. Raman spectroscopy analysis of MX-H and MX-B revealed 484.80 cm−1 Raman shift assigned to E1g phonon mode of (Ti, C, O). The ultraviolet UV visible absorption spectra explored pure and catalyst added Methylene Blue (MB) dye stock solution using annular type photoreactor with visible light source of 300 W. The comparatives of MAX, MX-H and MX-B samples was investigated as photocatalytic activity, The blender made (MX-B) sample revealed 98% of efficiency. [Display omitted] • Elevated class MXene (Ti 3 C 2) attained via homemade kitchen blender. • High shear mechanical exfoliation is required for efficient MXene delimitations. • Large-scale industrial productions of the MXene nanosheets. • 2D materials using a blender is a first-time novel approach. • The blender made (MX-B) sample revealed 98% of efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel CeO 2 /MoS 2 /rGO (CeMG) ternary composites using microwave method is proposed. • CeMG shows excellent specific capacitance of 635 F.g−1 as compared to CeO 2. • CeMG shows 88.9% capacitance retained after 10,000 cycles at 20 A.g−1. There is a huge requirement for renewable energy resources to avoid the usage of fossil fuel attracted the researchers to work on the energy storage devices, such as supercapacitors. Herein, the novel synthesis of CeO 2 @MoS 2 @rGO (CeMG) ternary composite by two step microwave synthetic route that will be employed as an outstanding electrode material for supercapacitor. In particular, the morphology studies confirm that the cerium oxide has spherical morphology with the controlled size in the range of 12–15 nm embedded with the layered sheets of MoS 2 and reduced graphene oxide. The CeMG composites exhibit excellent specific capacitance of 635 F g−1 which is achieved at the current density of 1 A g−1 compared to the pure CeO 2. In addition, prolonged cyclic stability with 88.9% capacitance is retained after 10,000 cycles of charging and discharging. [ABSTRACT FROM AUTHOR]

An electrochemically active composite material consisting of zinc vanadate (Zn 3 V 2 O 8) and nitrogen doped multi wall carbon nanotubes (N-MWNCT) was prepared using simple hydrothermal procedure. This attractive composite material was exploited as an electrode for the supercapacitor application. The multiple oxidation states of vanadium and stable zinc rendered wide range of redox reaction with MWCNT which was explored with K 2 SO 4 neutral electrolyte. The electron microscopic analysis along with XRD and XPS confirmed the formation of ternary composite. The unique combination of Zn 3 V 2 O 8 and N-MWNCT showed a specific capacitance of 403 F g−1 with better stability of 79% for 5000 cycles. The presence of N-MWCNT enhanced the performance of the ZVC composite by providing structural support which significantly reduced the charge transfer resistance R ct (1.3 Ω) and series resistance R s (1.8 Ω) by providing synergetic effects. The results have demonstrated the potential scope of ZVC for the energy storage device. Unlabelled Image • Electrochemically active composite of zinc vanadate (Zn3V2O8) and (N-MWNCT) was prepared using hydrothermal procedure. • Electron microscopic analysis along with XRD and XPS confirmed the formation of ternary composite. • The unique combination of Zn3V2O8@MWNCT (ZVC) recorded a specific capacitance of 403 F g-1 which is 89% higher than bare Zn3V2O8. • Considerable reduction in charge transfer resistance Rct (1.3) and series resistance Rs (1.8) for ZVC composites. • ZVC based asymmetric supercapacitor demonstrated better cyclic stability of 81% for 5000 cycles. [ABSTRACT FROM AUTHOR]

Co-precipitation assisted hydrothermal synthesis was employed to prepare Mn 3 O 4 electrocatalysts for efficient electrochemical water oxidation. Tetragonal structure of high crystalline and pure phase Mn 3 O 4 nanostructures was confirmed by X-ray diffraction (XRD) spectra. Physical characteristics such as vibration, optical and morphology of the electro catalysts were examined and confirmed by Raman spectra, Fourier Transform Infrared Spectra (FTIR), photoluminescence spectra (PL) and ultra-violet diffuse reflection spectra (UV-DRS) respectively. Mn 3 O 4 electro catalysts were deposited on GCE electrode for investigating the electrochemical behavior. The electrochemical water splitting application was demonstrated by the prepared Mn 3 O 4 electro catalysts in conventional three electrode cell with Hg/HgO as a reference electrode and Pt mesh as a counter electrode. Higher current density of 1.31 mA/g with lowest Tafel slope value of 63 mV/dec was achieved for the prepared electro catalyst synthesized in base pH condition. Good stability of 55% over 12 h long time was achieved for the electro catalysts in alkaline medium under continuous electrochemical reaction with good retention in performance. Hence, the controlled alkaline environmentally synthesized Mn 3 O 4 electro catalysts prepared in this work achieved the good standard of highly efficient electrode material for electrochemical water splitting applications. Image 1 • Controlled alkaline environment favours Mn 3 O 4 electrocatalysts preparation. • Higher current density of 1.31 mA/g with lowest Tafel slope value of 63 mV/dec was achieved. • Good stability of 55% over 12 h long time was achieved. [ABSTRACT FROM AUTHOR]

The study presents the binder-free synthesis of mixed metallic organic frameworks (MMOFs) supported on a ternary metal oxide (TMO) core as an innovative three-dimensional (3D) approach to enhance electron transport and mass transfer during the electrochemical charge-discharge process, resulting in high-performance hybrid supercapacitors. The research demonstrates that the choice of organic linkers can be used to tailor the morphology of these MMOFs, thus optimizing their electrochemical efficiency. Specifically, a NiCo-MOF@NiCoO 2 @Ni electrode, based on terephthalic linkers, exhibits highly ordered porosity and a vast internal surface area, achieving a maximum specific capacity of 2320 mC cm -2 , while maintaining excellent rate capability and cycle stability. With these performances, the hybrid supercapacitor (HSC) achieves a maximum specific capacitance of 424.6 mF cm -2 (specific capacity 653.8 mC cm -2 ) and 30.7 F cm -3 with energy density values of 10.1 mWh cm -3 at 167.4 mW cm -3 (139.8 µWh cm -2 at 2310 µW cm -2 ), which are higher than those of previously reported MMOFs based electrodes. This research introduces a novel approach for metal organic framework based HSC electrodes, diverging from the traditional emphasis on metal ions, in order to achieve the desired electrochemical performance., (© 2023 Wiley‐VCH GmbH.)

Supercapacitors (SCs) have emerged as attractive energy storage devices due to their rapid charge/discharge rates, long cycle life, and high-power density. However, the development of innovative electrode materials to achieve high-performance remains crucial to meet future requirements in supercapacitor technology. In this work, we have explored the potential of a microwave-engineered NiZrO 3 @GNP composite as a promising electrode material for SCs. A microwave assisted hydrothermal approach was adopted for the fabrication of the NiZrO 3 @GNP nanocomposite. Structural and morphological investigations showed its structural richness and its chemical compositions. When applied as a SC electrode, this innovative combination exhibits battery-like behaviour with higher specific capacity (577.63 C g -1 ) with good cyclic stability, and good performance. We have assembled an asymmetric-type two-electrode SC device and analysed its electrochemical features. This NiZrO 3 @GNP device exhibits the specific capacity of 47 C g -1 with capacitance retention of 70% after 2000 charge-discharge cycles. Further research on optimizing the synthesis process and exploring different device configurations could pave the way for even higher-performance supercapacitors in the future., Competing Interests: All authors declare that they have no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The polyhedron-structured NiSe 2 @MoSe 2 (NMS) were magnificently produced through hydrothermal method, which makes the active electrode very effective in accessing the redox active sites in the charge/discharge process in supercapacitor applications. Systematic studies of the structural and morphological features of the unique polyhedron NMS were performed. Laser Raman spectra reported the vibrational and rotational modes of NMS. NMS exhibited a maximum 1000 F g -1 (138.8 mA h g -1 ) specific capacitance at 1 A g -1 and attained a capacity retention of 77.67% for 5000 stable cycles at 10 A g -1 using 1 M KOH as an electrolyte. The well assembled asymmetric supercapacitor NMS hydrolyzed for 18 h//AC demonstrated an outstanding electrochemical performance with an improved 305 F g -1 specific capacitance attained at 1 A g -1 with a good cycle life of 87.35% and a capacity retention of over 5000 cycles. Herein, the combined contribution of both the Ni and Mo ions offers a richer redox chemistry, which is beneficial to a higher electrochemical activity. The experimental results indicate that the NMS electrode could be used as a high-performance electrode., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Waste water remediation is the ongoing hot research topic that can reduce the water scarcity all over the world. By reducing the pollutants in the waste water drawn from industries and other sources will be more useful for domestic purposes. To reduce the rate of pollutants in water may also help in improving the aquatic environment and decreases other side effects. Efficient and cost effective catalysts were in search for both dye degradation and water remediation treatment applications. NiMoO 4 nanorods were prepared by employing co-precipitation method with different stirrer time (2 h, 4 h and 6 h). The formation of NiMoO 4 was substantiated employing X-ray diffractometer analysis (XRD). Vibrational and rotational property of the samples was analyzed by FT-IR spectra and Raman spectra. The optical property was further confirmed by UV-vis spectral studies. Morphological analysis studies revealed growth of nanorods with 6 h stirrer time. The photocatalytic behavior of the obtained product was carried out under both UV light (364 nm) and visible light irradiation. The samples subjected to visible light environment showed better efficiency on degrading the methylene blue (MB) dye. The efficiency obtained under UV irradiation were 20%, 31%, 33%, 41% and efficiency obtained in visible light irradiation were 27%, 42%, 46%, 55% with respect to bare methylene blue (MB), MB with NiMoO 4 (2 h), MB with NiMoO 4 (4 h), MB with NiMoO 4 (6 h) catalyst added. NiMoO 4 sample with 6 h stirrer time and fine nanorods growth will be the good candidate for future use., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Electrochemical energy storage is a current research area to address energy challenges of the modern world. The Cu 2 FeSnS 4 /PVP/rGO-decorated nanocomposite using PVP as the surface ligand was explored in a simple one-step solvothermal route, for studying their electrochemical behavior by designing asymmetric hybrid supercapacitor devices. The full cell three-electrode arrangements delivered 748 C/g (62.36 mA h/g) at 5 mV/s employing CV and 328 F/g (45.55 mA h/g) at 0.5 A/g employing GCD for the Cu 2 FeSnS 4 /PVP/rGO electrode. The half-cell two-electrode device can endow with 73 W h/kg and 749 W/kg at 1 A/g energy and power density. Furthermore, two Cu 2 FeSnS 4 /PVP/rGO//AC asymmetric devices connected in series for illuminating a commercial red LED more than 1 min were explored. This work focuses the potential use of transition-metal chalcogenide composite and introduces a new material for designing high-performance supercapacitor applications., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Herein, we report a novel, low-temperature solvothermal method to grow 3D-Bi2O3 flower-like microspheres on Ti substrates as a binder-free negative electrode for supercapacitor applications. The Bi2O3/Ti electrode showed an areal capacitance of 1.65 F cm-2 at 4 mA cm-2. Moreover, the 3D-NiCo2O4||3D-Bi2O3 hybrid device delivered high energy and power densities of 31.17 μW h cm-2 and 7500 μW cm-2, respectively. The more optimal energy storage performance based on the strong adhesion of the current collector and self-assembled three-dimensional nanostructures permits efficient electron and ion transportation.

Comparative investigation of the electrochemical oxygen evolution reaction (OER) activity for clean energy production was performed by fabricating three different electrodes, namely, NiSe 2 , CoSe 2 , and CoNiSe 2 , synthesized by hydrothermal treatment. Cubic, orthorhombic, and hexagonal structures of NiSe 2 , CoSe 2 , and CoNiSe 2 were confirmed by X-ray diffraction (XRD) and also by other characterization studies. Perfect nanospheres, combination of distorted nanospheres and tiny nanoparticles, and sharp-edge nanostructures of NiSe 2 , CoSe 2 , and CoNiSe 2 were explored by surface morphological images. Higher OER activity of the binary CoNiSe 2 electrode was achieved as 188 mA/g current density with a comparatively low overpotential of 234 mV along with higher conductivity and low charge transfer resistance when compared to its unary NiSe 2 and CoSe 2 electrodes. A low Tafel slope value of 82 mV/dec was also achieved for the same binary CoNiSe 2 electrode in a half-cell configuration. The overall 100% retention achieved for all of the fabricated electrodes in a stability test of OER activity suggested that the excellent optimum condition was obtained during the synthesis. This could definitely be a revelation in the synthesis of novel binary combinations of affordable metal selenides for clean energy production., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

In this study, a general and effective phosphorization strategy is demonstrated to enhance the super capacitor performance of Ni, Cu, and Mn transition metals. The composites such as Ni₃(PO₄)₂, Cu₃(PO₄)₂ and Mn₃(PO₄)₂ were achieved by employing hydrothermal method mixing with ethylene glycol. These composite nanostructures were characterized by standard sophisticated techniques such as XRD, RAMAN, FTIR, UV, PL and SEM studies. X-ray diffraction (XRD) studies revealed the monoclinic crystallographic structure of the materials. The optical and vibrational properties of the product are characterized by photoluminescence and FTIR studies. These prepared materials have shown desired electrochemical stability. The above characterization indicates the functional groups and materials nature. The electrochemical properties of synthesized phosphate materials are analyzed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charging and discharging studies (GCD). The Cu₃(PO₄)₂ electrode showed a remarkable specific capacitance of 232.025 F g -1 at a scan rate of 20 mV/s, which is expected to have a promising electrode for super capacitor applications. The GCD study of synthesized Cu₃(PO₄)₂ nanostructure has also been tested for 1000 cycles at 10 A/g current density to evaluate the cyclic stability of the electrode and retains 94% of initial specific capacitance.

A copper sulfide nanoflakes-decorated carbon nanofragments-modified glassy carbon electrode (CuS-CNF/GCE) was fabricated for the electrocatalytic differentiation and determination of hydroquinone (HQ) and catechol (CC). The physicochemical properties of the CuS-CNF were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. The electrocatalytic determination of HQ and CC over the CuS-CNF/GCE was evaluated by cyclic voltammetry and differential pulse voltammetry. An excellent detection limit and sensitivity of the CuS-CNF/GCE are obtained (0.293 µM and 0.259 µM) with a sensitivity of 184 nA µM -1 cm -2 and 208 nA µM -1 cm -2 (S/N=3) for HQ and CC, respectively. In addition, the CuS-CNF/GCE shows a selective identification of HQ and CC over potential interfering metal ions (Zn 2+ , Na + , K + , NO 3- , SO 4 2- , Cl - ) and organic compounds (ascorbic acid, glucose), and a satisfactory recovery is also obtained in the spiked water samples. These results suggest that the CuS-CNF/GCE can be used as an efficient electrochemical sensor for the simultaneous determination of co-existing environmental pollutants such as HQ and CC in water environments with high selectivity and acceptable reproducibility.

Wire type supercapacitors with high energy and power densities have generated considerable interest in wearable applications. Herein, we report a novel NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire electrode for high performance supercapacitor application. In this work, a facile method is introduced to fabricate a 3D, porous Ni film deposited on a Ni wire as a flexible electrode, followed by decoration with NiCo 2 S 4 as an electroactive material. The fabricated NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire electrode displays a superior performance with an areal and volumetric capacitance of 1.228 F cm -2 and 199.74 F cm -3 , respectively, at a current density of 0.2 mA cm -1 with a maximum volumetric energy and power density (E V : 6.935 mW h cm -3 ; P V : 1.019 W cm -3 ). Finally, the solid state asymmetric wire type supercapacitor is fabricated using the fabricated NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire as a positive electrode and N-doped reduced graphene oxide (N-rGO) as a negative electrode and this exhibits good areal and volumetric capacitances of C A : 0.12 F cm -2 and C V : 19.57 F cm -2 with a higher rate capability (92%). This asymmetric wire type supercapacitor demonstrates a low leakage current and self-discharge with a maximum volumetric energy (E V : 5.33 mW h cm -3 ) and power (P V : 855.69 mW cm -3 ) density.

A lightweight, flexible, cost-effective, and robust, single-electrode-based Smart Seat-Triboelectric Nanogenerator (SS-TENG) is introduced as a promising eco-friendly approach for harvesting energy from the living environment, for use in integrated self-powered systems. An effective method for harvesting biomechanical energy from human motion such as walking, running, and sitting, utilizing widely adaptable everyday contact materials (newspaper, denim, polyethylene covers, and bus cards) is demonstrated. The working mechanism of the SS-TENG is based on the generation and transfer of triboelectric charge carriers between the active layer and user-friendly contact materials. The performance of SS-TENG (52 V and 5.2 μA for a multiunit SS-TENG) is systematically studied and demonstrated in a range of applications including a self-powered passenger seat number indicator and a STOP-indicator using LEDs, using a simple logical circuit. Harvested energy is used as a direct power source to drive 60 blue and green commercially available LEDs and a monochrome LCD. This feasibility study confirms that triboelectric nanogenerators are a suitable technology for energy harvesting from human motion during transportation, which could be used to operate a variety of wireless devices, GPS systems, electronic devices, and other sensors during travel.

A new paradigm in cancer theranostics is enabled by safe multifunctional nanoplatform that can be applied for therapeutic functions together with imaging capabilities. Herein, we develop a multifunctional nanocomposite consisting of Graphene Oxide-Iron Oxide -Doxorubicin (GO-IO-DOX) as a theranostic cancer platform. The smart magnetic nanoplatform acts both as a hyperthermic agent that delivers heat when an alternating magnetic field is applied and a chemotherapeutic agent in a cancer environment by providing a pH-dependent drug release to administer a synergistic anticancer treatment with an enhanced T2 contrast for MRI. The novel GO-IO-DOX nanocomposites were tested in vitro and were observed to exhibit an enhanced tumoricidal effect through both hyperthermia and cancer cell-specific DOX release along with an excellent MRI performance, enabling a versatile theranostic platform for cancer. Moreover the localized antitumor effects of GO-IO-DOX increased substantially as a result of the drug sensitization through repeated application of hyperthermia.

We demonstrate a flexible piezoelectric nanogenerator (PNG) constructed using a hybrid (or composite) film composed of highly crystalline BaTi(1-x)Zr(x)O3 (x = 0, 0.05, 0.1, 0.15, and 0.2) nanocubes (abbreviated as BTZO) synthesized using a molten-salt process embedded into a poly(vinylidene fluoride) (PVDF) matrix solution via ultrasonication. The potential of a BTZO/PVDF hybrid film is realized in fabricating eco-friendly devices, active sensors, and flexible nanogenerators to interpret its functionality. Our strategy is based on the incorporation of various Zr(4+) doping ratios into the Ti(4+) site of BaTiO3 nanocubes to enhance the performance of the PNG. The flexible nanogenerator (BTZO/PVDF) exhibits a high electrical output up to ∼11.9 V and ∼1.35 μA compared to the nanogenerator (BTO/PVDF) output of 7.99 V and 1.01 μA upon the application of cyclic pushing-releasing frequencies with a constant load (11 N). We also demonstrate another exciting application of the PNG as a self-powered sensor to measure different water velocities at an outlet pipe. The average maximum peak power of the PNG varies from 0.2 to 15.8 nW for water velocities ranging from 31.43 to 125.7 m/s during the water ON condition. This study shows the compositional dependence approach, fabrication of nanostructures for energy harvesting, and self-powered devices in the field of monitoring for remote area applications.

In this work, we have fabricated a piezoelectric-driven self-charging supercapacitor power cell (SCSPC) using MnO2 nanowires as positive and negative electrodes and a polyvinylidene difluoride (PVDF)-ZnO film as a separator (as well as a piezoelectric), which directly converts mechanical energy into electrochemical energy. Such a SCSPC consists of a nanogenerator, a supercapacitor, and a power-management system, which can be directly used as a power source. The self-charging capability of SCSPC was demonstrated by mechanical deformation under human palm impact. The SCSPC can be charged to 110 mV (aluminum foil) in 300 s under palm impact. In addition, the green light-emitting diode glowed using serially connected SCSPC as the power source. This finding opens up the possibility of making self-powered flexible hybrid electronic devices.

We report the gate-tunable photoresponse of a defective graphene over the ultraviolet (UV) and the visible light illumination, where the defect was generated by plasma irradiation. Plasma induced Dirac point shift indicates the p-doping effect. Interestingly the defective-graphene field effect transistor (defective-GFET) showed a negative shift upon UV illumination, whereas the device showed a positive shift under visible light illumination, along with the change in the photocurrent. The defective-GFET device showed a high photoresponsivity of 37 mA W(-1) under visible light, that is ∼3 times higher than that of the pristine graphene device. Photoinduced molecular desorption causes the UV light responsivity to 18 mA W(-1). This study shows that the tunable photodetector with high responsivity is feasible by introducing an artificial defect on graphene surface.

In this study, we developed an innovative, flexible, organic-inorganic hybrid composite nanogenerator, which was used to drive a self-powered microwire-based pH sensor. The hybrid composite nanogenerator was fabricated using ZnO nanowire and piezoelectric polymer poly(vinylidene fluoride), through a simple, inexpensive solution-casting technique. The fabricated hybrid composite nanogenerator delivered a maximum open-circuit voltage of 6.9 V and a short-circuit current of 0.96 μA, with an output power of 6.624 μW under uniaxial compression. This high-performance, electric poling free composite nanogenerator opens up the possibility of industrial-scale fabrication. The hybrid nanogenerator demonstrated its ability to drive five green LEDs simultaneously, without using an energy-storage device. Additionally, we constructed a self-powered pH sensor, using a ZnO microwire powered with our hybrid nanogenerator. The output voltage varied according to changes in the pH level. This study demonstrates the feasibility of using a hybrid nanogenerator as a self-powered device that can be extended for use as a biosensor for environmental monitoring and/or as a smart, wearable, vibration sensor in future applications.

We report the electronic characteristics of an avant-garde graphene-field-effect transistor (G-FETs) based on ZnO microwire as top-gate electrode with self-induced dielectric layer. Surface-adsorbed oxygen is wrapped up the ZnO microwire to provide high electrostatic gate-channel capacitance. This nonconventional device structure yields an on-current of 175 μA, on/off current ratio of 55, and a device mobility exceeding 1630 cm(2)/(V s) for holes and 1240 cm(2)/(V s) for electrons at room temperature. Self-induced gate dielectric process prevents G-FETs from impurity doping and defect formation in graphene lattice and facilitates the lithographic process. Performance degradation of G-FETs can be overcome by this avant-garde device structure.