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The study divulges the enhanced electrochemical performance of sonochemicaly synthesized cobalt phosphate by inclusion of magnetron sputtered Ag nano-islands. The morphological, structural, and compositional insight of materials, is analyzed by using various analytical techniques like Optical, atomic force microscopy (AFM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-Ray analysis (EDX). Initially, the electrochemical performance of the electrodes is tested in three-electrode assembly. The results reveal that Co3(PO4)2 with silver current collector (Ag- Co3(PO4)2) profits an enhanced specific capacity (Qs) of 502 Cg−1 compare to pristine (273 Ag−1) at 0.6 Ag−1. To validate the real time application supercapattery device is fabricated by coupling Ag-Co3(PO4)2 (positive electrode) with AC (negative electrode). The supercapattery holds an excellent specific energy of 65.8 Whkg−1 at corresponding specific power of 510 Wkg−1 at 0.6 Ag−1 and the maximum specific power is 6012 Wkg−1 at 7 Ag−1. The device unveiled a stability potential of 85.6% after 10,000 continuous GCD cycles. Additionally, the contribution of diffusive and capacitive mechanisms in the entire charge storage capacity of the supercapattery is estimated by employing Dunn’s analysis. The results portray the inclusion of silver as a fine drive toward high performance electrodes for potential supercapattery applications.

ZnS film with various thicknesses (d ≈ 100–350 nm) deposited on the ITO coated glass substrate (ZnS/ITO/glass) by an electron beam evaporation process was examined structurally and optically. Different techniques were used to specify and analyze the optical characteristics of the film, such as spectroscopic ellipsometric (SE) and spectrophotometric (SP). The ZnS/ITO/glass films exhibit a wurtzite hexagonal type structure entrenched in the crystalline background of ITO film. XRD analysis revealed changes in structural and microstructural parameters, such as a decrease in lattice parameters, a reduction in microstrain, and a raise in crystallite size. The optical constants and the optical energy gap were extracted from SE by constructing an ellipsometric optical model, while the optical constants were calculated from SP by using Murmann's exact equations. It was seen that the overall behaviour of the refractive index n of the ZnS/ITO/glass films obtained from SE and SP increases with an increase in ZnS layer thickness, which is attributed to the increment of the size of the grain. It was additionally found that, the overall behaviour of the extinction coefficient k of the ZnS/ITO/glass films increases, when the thickness of the ZnS layer increments. Also, the direct optical transition was observed with energy band gap diminishes from 3.423 (d = 100 nm) eV to 3.287 eV (d = 350 nm) that is because of the rise in grain size, the decrease in microstrain, and reduction in lattice constants. Furthermore, it was found that the deposition of ZnS on ITO coated glass substrate increases the absorption compared with the ZnS/glass film and then reduces the transmittance and energy band gap. It was concluded that as the ZnS thickness increases, the optical constants of ZnS/ITO/glass films enhance. Finally, the overall behaviour of the optical constants within the experimental error range of the ZnS/ITO/glass films with different ZnS layer thicknesses obtained by SE was found to be consistent with that calculated from SP measurement.

Supercapacitors with prestigious electrochemical performance have achieved exceptional worth however, a facile environmentally friendly approach is still desired for electrode material with high charge storage capability. In this study, we have demonstrated the facile synthesis of activated carbon (AC) and strontium phosphate (Sr3(PO4)2) (sonochemical approach) ) for energy storage applications. The surface morphology and crystal structure of the synthesized materials are investigated via performing X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The electrochemical performance of synthesized material is carried out in three electrode assembly. The Sr3(PO4)2 reveals utmost specific capacity of 220 Cg−1 at 0.5 Ag−1 whereas, the AC delivers the high specific capacitance of 319.41 Fg−1 at 1 Ag−1 respectively. This synthesized materials are further employed in an hybrid architecture for real device application. The Sr3(PO4)2 is utilized as positive and AC as negative electrode. The fabricated device delivers excellent specific energy of 25.4 Whkg−1 at specific power of 425 Wkg−1. The maximum specific power 1870 Wkg−1 is also achieved along with specific energy of 14.5 Whkg−1. The device reveals the excellent capacity retention of 90 % after 3000 GCD series. Furthermore, the kinetics of charge storage mechanism is studied for the device by applying Dunn's model and the diffusive and capacitive contribution in overall device capacity is investigated. Moreover, the power law is utilized to confirm the hybrid nature of the device by calculating the b values. The projected approach result in electrode materials that have delivered potential energy storage performance.

Porous anodic alumina (PAA), comprising arranged pores in hexagonal cells obtained by anodizing aluminum (Al), has been studied and is usually used as a template for synthesizing one-dimensional nanostructure. However, there is growing interest in more effective applications with tunable pores and more complex structures with reasonable cost. For example, the branching and interconnected pores are obtained in multiple bifurcations under certain anodizing conditions. From manufacturing perspectives, large-area anodization on special substrates, such as Si, is extremely significant and required. Herein, we present a robust analysis of the different types of branched and modulated pores in the PAA templates; the newly developed methodology and the morphological evolution of each type are discussed. The proposed anodizing strategies help reduce anodizing time and result in smaller pore sizes than those obtained by the traditional methods. Therefore, they be effectively implemented for separation science technology. Furthermore, the work was extended to anodize a full Al wafer (200 mm in diameter) on a Si wafer without lithography or pretemplating. Additionally, the required anodizing conditions to prevent PAA from burning were followed. The opportunities for this PAA template to serve as generic templates for potential applications will be explored and discussed. The anodization of annealed Al/SiO2 films can be used to create highly hexagonal ordered arrays of alumina nanodots between alumina and SiO2 substrate, which were observed when the anodized sample was cleaved. Therefore, the obtained results could help, from manufacturing perspectives, modulate pores and a large area of the PAA on special substrates, such as Si, for many technological applications.

Thin films of CdS1-xCux (with 0 ≤ x ≤ 0.10) were deposited using electron beam evaporation. Using XRD, EDX, SEM and UV–Vis–NIR spectroscopy, the impact of [Cu]/[S] on the film properties was examined. The influences of various concentrations of Cu are also elucidated on the optical parameters of the films. The XRD analysis shows that the thin films of CdS1-xCux have been improved and have hexagonal polycrystalline structure with the increase of Cu doping ratio. Additionally, the crystallite size is reduced while the micro-strain e increases with enhancement of the incorporation of Cu in CdS lattice. The envelope method was used to extract the optical parameters of the undoped and Cu-doped CdS films. With the increase of Cu concentration, the energy optical bandgap decreased, and the variation values of band gap could play an important role in solar cell applications. Another optical parameters such as, dissipation factor and real/imaginary dielectric constant parts were evaluated and demonstrated a strong Cu doping dependence. The shift observed in the photoluminescence spectra emission band confirmed Cu's substitution to CdS lattice. The measurements of magnetization using vibrating sample magnetometer illustrated a hysteresis loop in Cu-doped CdS films, and confirmed the room temperature ferromagnetism. Finally, the Hall effect results show that the pure CdS film corresponds to an n-type semiconductor with a resistivity of 8.11 × 10-2 Ω cm and a carrier concentration of 29.6 × 1019 cm-3, and the CdS:Cu film is a p-type semiconductor and the resistivity is reduced from 6.8 × 10-2 to 3.7 × 10-2 Ωcm, and the carrier concentration is reduced from 26.4 × 1019 to 4.1 × 1019 cm-3, which has potential application prospects in solar cells.

The liquid electrolytes for dye-sensitized solar cells (DSSCs) have been identified as one of main obstacles for commercialization. One possible way to resolve this problem is to employ the semi-solid electrolyte. In this respect, we apply two types of electrolytes, namely liquid and low molecular weight organic gelator (LMOG) to fabricate the semi-solid state DSSCs and investigate their effects over the efficiency and long-standing thermal stability of devices. Unlike the conventional TiO2 nanoparticulate films, we have introduce a hybrid oxide layer consisting of nanocomposites of TiO2 nanospheres (NSPs) mingled with ZnO nanofibers (NFs) namely (mixed ZnO NFs + TiO2 NSPs) produced by a novel electrospray technique. This route resulted in an effective contact between the electrolyte and the highly porous layer of dye-coated hybrid film as the gel electrolyte penetrated within the pores. The semi-solid state DSSCs fabricated using hybrid oxide films for the LMGO based electrolyte exhibits power conversion efficiency (PCE) of 9.51%, which is considerably greater compared to cells based on TiO2 nanoparticulate films (5.14%). The semi-solid state DSSCs using the LMOG-based gel electrolyte demonstrate the significantly improved device performance and stability compared to the devices using the liquid electrolyte owing to their enhanced light trapping which serves as a scattering layer. Remarkably, the champion devices based on gel electrolyte produce the maximum PCE of 10.69%, the highest efficiency reported so far for these types of devices.

This work demonstrates the electrochemical performance of binary as well as ternary metal phosphates synthesized via a cost-effective and facile sonochemical approach. The structural elemental and morphological study of the as-synthesized was investigated via XRD, EDX and SEM. The electrochemical performance of synthesized material was investigated in three and two cell configuration. An outstanding performance was delivered via copper doped cobalt manganese phosphate (Co0.125Cu0.375Mn0.50(PO4)2.) which leads to a specific capacity of 498.2 at 3 mV/s and 483 C/g at 0.5 A/g. This electrode material was utilized as positive electrode material in an asymmetric (supercappatery) device. The activated carbon was employed as a negative electrode material. The fabricated device delivers splendid specific energy of 56 Wh/kg with a specific power of 800 W/kg holds an outstanding specific power of 6420 W/kg while still retaining specific energy of 16.88 Wh/kg. Moreover, the device praises excellent capacity retention of 97.2% after 2000 consective GCD cycles. The supercapattery performance was also analyzed via a simulation approach to investigate the contribution of capacitive and diffusion controlled mechanisms. A maximum capacitive and diffusion contribution of 34.2 (at 60 mV/s) and 86.4% (at 3 mV/s) respectively was observed in aggregate device performance. The morphological and compositional properties along with excellent electrochemical performance make Co0.125Cu0.375Mn0.50(PO4)2 a valuable electrode material for the development of advanced energy storage devices.

Asymmetric devices are fabricated by cramming the active material Co3O4/C composite (positive electrode) with activated carbon (negative electrode). Devices are examined under aqueous and gelled electrolyte. The theoretical model is adopted to study the charge storage mechanism in two devices. It has been observed that the capacitive and diffusion-controlled contribution of electrode material is affected by the phase change of electrolyte. Diffusive contribution is prominent in case of 1 M KOH aqueous electrolyte while more capacitive contribution has been noticed in PVA-KOH-C gelled electrolyte. By changing the phase of electrolyte, the potential window is enhanced which upsurges the energy density of device. For commercial applications, solid state device exhibits more energy storage and have high safety standards than aqueous electrolyte-based devices.

In this manuscript, we have reported the simultaneous enhancement in Seebeck coefficient and electrical conductivity by controlling the density and size of the grains. The grain boundaries are acting as barriers for the low energy carriers at the grain boundaries, which resulted in the enhancement of mobility of carriers. The high mobility of carriers simultaneously enhances the Seebeck coefficient and conductivity of the material under investigation. This argument was tested by deliberately engineering the grain boundaries in bulk Zinc Tin Oxide (ZnSnO) by the post thermal annealing method. The ZnSnO pallets were prepared by mixing of ZnO and Sn metal powders (24:1) by hydraulic press at very high pressure. SEM images demonstrated that the grain boundaries were found to be increased with increase in annealing temperature. It was observed that the values of Seebeck coefficient and power factor were increased to maximum (120 μV/°C and 4.8 × 10 − 4 W m−1 K−2 respectively) at maximum annealing temperature. While the supplementary measurements like XRD and Raman spectroscopy were used to support this argument.

In current research work we have able to enhanced the thermoelectric power generation ability of ZnO using two different methods simultaneously i. e alloying with Al atoms and post growth annealing method. ZnAlO alloy having different Al concentration (1, 1.5 and 2%) was converted into pallets after mixing Al and zinc oxide powders using hydraulic press having 13 tons pressure. The prepared pellets were subjected to high temperature annealing ranging from 700-900oC with step of 50 °C for each doping concentration. The crystal structure of all un-annealed and annealed samples was verified by XRD and Raman spectroscopy measurements. Seebeck data suggested that ZnAlO sample with 1% Al concentration and annealed at 700 °C has a maximum value of Seebeck coefficient 481 μV/°C and this value was enhanced to 1017 μV/°C as the measurement temperature increase from 25 °C to 100 °C. The electrical conductivity measured using Hall Effect showed an increasing trend with an increase in doping concentration as well as with post annealing temperature. The observed behavior of Seebeck coefficient and electrical conductivity with Al atoms concentration and annealing temperature suggested the enhancement of carrier mobility. The optimized values of Al concentration (1%) and annealing temperature (700 °C) are due to the fact that carrier scattering phenomena changes from lattice scattering to impurity scattering.

This study demonstrates a cost-effective, facile and green synthesis of nickel-manganese (Ni-Mn) based binary metallic phosphates through a one-step sono-chemical method followed by calcination at 400 °C. The composites are further modified by changing the aspect ratio of Mn in Ni and utilized for high performance energy storage applications. The structure morphology of synthesized nanomaterials is investigated by performing X-ray diffraction (XRD) analysis. Among all, the composite with a concentration of Ni0.75:Mn0.25(PO4)2 exhibit the outstanding electrochemical performance by indicating high specific capacity (Qs) of 788.4 Cg−1 in three-electrode assembly. At last, the supercapattery is fabricated comprising of active material Ni0.75Mn0.25(PO4)2 as positive and activated carbon as negative electrode, which reveal exceptional results with a high specific energy and specific power of 64.2 Whkg−1 and 11,896 Wkg−1, respectively. This supercapattery device demonstrates excellent cyclic stability of 119% after 2000 continues GCD cycles. Our investigation reveals that the facile synthesis of these nanomaterials along with excellent electrochemical performance makes them valuable for the development of advanced high-performance energy storage devices.

In this work, we have demonstrated, a facile synthesis of the ternary composite of strontium oxide-polyaniline-graphene (SrO-PANI-Gr) for hybrid energy storage applications. The electrochemical performance of the synthesized material is initially characterized in three electrode assembly. This nanomaterial indicates a specific capacity of 164C/g. In order to enhance the electrochemical performance of pristine SrO (S1), it is further physically blended with polyaniline in a 50/50% mass ratio which shows a specific capacity of 200C/g with lower rate capability. To further improve electrochemical performance with no compromise on rate capability, the material (S2) is further blended with graphene and this composition indicates an excellent specific capacity of 296C/g with better rate capability than the S2. To investigate the real device performance, a supercapattery device (S3//activated carbon) is fabricated which exhibits a maximum specific capacity of 151.66C/g. The assembled supercapattery device yields a maximum specific energy of 33.8 Wh.kg-1 along with maximum specific power of 3962.13 W.kg-1. Moreover, the supercapattery device demonstrated an excellent capacity retention of 80% after continuous 3000 charge discharge cycles. To further investigate the performance evaluation a theoretical model proposed by Dunn and co-workers is applied to investigate the capacitive (non-faradaic) and diffusive (faradaic) contribution in the charge storage of the supercapattery. The diffusive contribution is found dominant at lower scan rates whereas the capacitive contribution is dominant at higher scan rates. This variation in the contribution is attributed to the interaction time of the electrolyte charge with the electrode material.

In this framework, a novel Ge20+xSe80-x thin films ~890 nm, with (x = 5, 10, 15, 20, 25, and 30 at. %) were synthesized via thermally evaporation method at 298 K. The elemental ratios of Ge–Se thin films have been checked by EDX analysis and also the amorphous natural was confirmed through X-Ray Diffractometer, XRD. In thin films belonging to the glass chalcogenide, in the case of existence of interference in the optical measurements-namely, transmittance, T and reflectance, R spectra-often the dispersion refractive index, n ( λ ) and the thickness of the thin film, d were computed based on the spectrum of transmittance or reflectance and also the wavelength along with the optical measurements. In this work, the real optical constant n ( λ ) and film's thickness of Ge–Se thin films have been computed utilizing the wavelength measurements of the normal and slightly inclined incidence light solely. Then, the linear optical parameters such as Tauc's energy E g and Urbach's energy E e , the linear imaginary optical constant, namely, absorption index or extinction coefficient k e x , the linear dispersion parameters, namely, the single oscillator energy E o and the dispersion energy E d and the non-linear optical constant or so called the second-order of refractive index n 2 have been determined. The optical dispersion d n d λ , phase velocity v p , group velocity U g , Magneto-Optical Constant or Verdet coefficient V ( λ ) and the positions of the energy levels have been discussed in detail.

A facile methodology has been adopted for the synthesis of cobalt oxide (Co3O4) by wet chemical technique followed by the calcination and prepared Co3O4/C composite for energy storage devices. Initially, SEM and XRD are carried out to analyze the surface characterizations of electrode material. The electrochemical properties of synthesized material has been investigated and the maximum specific capacitance of 567 F/g is achieved for Co3O4/C composite at 3 mV/s scan rate. Co3O4/C composite and activated carbon (AC) are sandwiching and separated with PVA-KOH-C gel electrolyte. The device has been examined at several scan rates and current densities demonstrating better performance with maximum energy density of 63 Wh/kg at 0.7 A/g. The capacitive retentivity is 82 % after 6000 charge/discharge cycles. The solid-state devices are showing a tremendous performance with high energy and power density and are safe to handle due to no seepage which can be utilized for the next generation.

A variety of high-quality, shape and size consistent nanostructures of copper sulfide (CuS) in the form of hierarchical architectures composed of intersecting nano-sheets have been fabricated via mixed solvent route. Copper chloride and thiourea have been utilized as precursors for copper and sulfur sources for each experimentation in the presence of a variety of mixed solvents to obtain various morphologies of CuS. The prepared products have been characterized by X-ray powder diffraction (XRD) and all of the synthesized products have been investigated to be the phase pure single crystalline. Scanning Electron Microscopy (SEM) revealed the well-ordered and isolated particles. The Energy Dispersive Spectroscopy (EDS) spectrum further proved that the obtained products in all of the synthetic processes don’t contain any kind of impurity. Ultraviolet– visible–near infrared (UV–vis–NIR) transmittance spectrophotometer has been utilized to ascertain the optical properties of the as prepared nanostructures. An extended U.V absorption in near-IR region, indicate the covellite phase of CuS. Most importantly, the synthesized nanostructures demonstrated an excellent photo-catalyst response in degrading highly concentrated rhodamine B (RhB) dye aqueous solutions under visible light irradiation along with an excellent reusability, suggesting a promising application in wastewater purification. The excellent photo-catalytic activity has been attributed to surface hierarchical structure with good absorbing and adsorbing properties, high visible light utilization and low electron hole recombination rate.

Supercapattery a combo of supercapacitors and batteries that embraces the features of both technologies in a single assembly. To justify this claim, a systematic approach has been employed to evaluate the performance of the combo device. In this regard a novel material is synthesized via hydrothermal technique and later on physically blended with polyaniline (PANI) to boost the performance of the pristine material. This matrix material expresses excellent performance by showing a specific capacity of 154 C/g in cyclic voltammetry (CV) and 162 C/g in galvanostatic charge discharge (GCD). Furthermore, this electrode material was sandwiched with activated carbon to fabricate the supercapattery device. The supercapattery performance was evaluated through CV, GCD, and electrochemical impedance spectroscopy (EIS). This device indicates a specific capacity of 104 C/g, 23.11 Wh/kg specific energy, and 6400 W/kg of specific power. Finally, a theoretical Dunn's model was applied to eliminate the faradaic and non-faradaic contribution of the real device. It was evidenced that the device storage was not purely faradaic (diffusive) neither non-faradaic (capacitive), but it is the combination of both contribution. The capacitive and diffusive contribution was found dependent on the scan rate and was due to the time offered to the ions for interaction with the electrode material. Our study offers the development of novel metal-organic framework/polyaniline-based electrode material for supercapattery devices as well as a unique route to probe the performance of the supercapattery.

In this study, low-dimensional (LD) MgO nanostructured thin films with three different morphologies, namely, nanowires (NWs), nanotubes (NTs) and nanoparticles (NPs) were fabricated by a vapor transport method on quartz and silicon substrates under optimum growth conditions. It was found that the deposition parameters have great influences on the morphology, optical, photoluminescent, electrical, gas sensing and magnetic behavior of the resulting products. X-ray diffraction analysis illustrated that all three LD MgO nanostructures have five expected Bragg peaks of cubic MgO phase purity with well crystalline nature. The morphology and diameter of LD MgO nanostructures were probed by scanning electron and transmission electron-microscopes. The optical band gap values for LD MgO nanostructure films varies between 3.65 eV and 3.95 eV depending on growth conditions. It was found that all MgO films exhibit two distinguishing PL peaks related to the near band edge luminescence of LD MgO nanostructures and defect levels produced by oxygen vacancies, respectively. It was found that the dependence of electrical conductivity on film morphology can be attributed to the defect levels produced by O2- ion vacancies during the synthesis process. NH3 gas sensing efficiency of LD MgO nanostructures with various morphologies were carried out at different operating temperatures from 25 °C to 300 °C. The MgO film with NWs structure has the highest sensor response value of 27 at 100 °C and the film with NPs structure has the lowest response value of 12 at 150 °C. Ferromagnetic order has been recorded for all morphologies at room temperature with clear hysteresis loop and different magnetic parameters depending on growth conditions. Thus, our results present a direct route for the growth of high-quality and diverse LD MgO nanostructures developed via vapor transport for many technological applications.

Thin bilayers of contrasting nanomaterials are ubiquitous in solution-processed electronic devices and have potential relevance to a number of applications in flexible electronics. Motivated by recent mesoscopic simulations demonstrating synergistic mechanical interactions between thin films of single-wall carbon nanotubes (SWCNTs) and spherical nanocrystal (NC) inclusions, we use a thin-film wrinkling approach to query the compressive mechanics of hybrid nanotube/nanocrystal coatings adhered to soft polymer substrates. Our results show an almost 2-fold enhancement in the Young modulus of a sufficiently thin SWCNT film associated with the presence of a thin interpenetrating overlayer of semiconductor NCs. Mesoscopic distinct-element method simulations further support the experimental findings by showing that the additional noncovalent interfaces introduced by nanocrystals enhance the modulus of the SWCNT network and hinder network wrinkling.

Lamellar nanosheets of contrasting materials are ubiquitous in functional coatings and electronic devices. They also represent a unique paradigm for polymer nanocomposites. Here, we use fluid-assembled lamellar nanosheets – alternating layers of polymer and single-wall carbon nanotubes (SWCNTs) – to gain insight into the flexural mechanics of such hybrid films. Specifically, we measure the modulus and yield strain as a function of both layer thickness and the total number of layers. Overall, we find that the multi-layered films exhibit the greatest synergistic effects near a layer thickness of 20 nm or less, which we relate to the characteristic width of the SWCNT–polymer interface. For all layer thicknesses, we find that the nanosheets have realized the bulk limit by six layers. Our results have potentially profound implications for controlling the rigidity and durability of polymer nanocomposites, thin hybrid films and flexible heterojunctions.