A set of MgAl2O4 aluminate-based phosphors doped with Bi3+ (0.01–0.04) and co-doped with alkali cations (Li+, Na+, and K+) was synthesized for the blue lighting application. The refinement of powder X-ray diffraction (XRD) data confirms cubic crystalline structure. When monitored with 424 nm, all phosphors under study showed strong absorption peak at 345 nm. Hence, excitation with 345 nm results in intense photoluminescence (PL) emission at 424 nm, ascribed to Bi3+ emission transition 3P1-1S0. Among the Bi3+ single-doped samples, MgAl2O4:0.03 Bi3+ exhibited optimal PL intensity, while further doping led to concentration quenching. The decay time for all the phosphor seems to fall within microsecond range and reducing with decreasing Bi3+ doping concentration. To applied the co-doping strategy, MgAl2O4:0.03 Bi3+ phosphor co-doped with alkali metals (Li+, Na+, and K+). Co-doping with Li⁺ an K⁺ ions enhancing the PL intensity by factors of approximately 1.2 and 1.5, respectively, while co-doping of Na+ not contributed much. By means of photometric results, it is found that the phosphor showed highly color pure blue emission. The comparison emission spectrum of the phosphor with the absorption spectrum chlorophyll a suggests significant similarity, thus the phosphor have potential to be utilized in plant growth lighting.

This paper presents the preparation of PMMA, PVDF-HFP, and their polymer blends using solution casting technique. We examined the films we created using Scanning Electron Microscopy (SEM), Energy Dispersive Xray Spectroscopy (EDAX), Differential Scanning Calorimetry (DSC), and Impedance Spectroscopy. SEM images revealed that pure PMMA exhibited a smooth morphology, PVDF-HFP displayed granular porosity, and blends with increased PVDF-HFP content demonstrated enhanced porosity. EDAX showed that the elements in the blends were evenly spread out, which meant that they were mixed well and did not separate into different phases. The DSC study demonstrated that the incorporation of additional PVDF-HFP alters the thermal behavior of the blends by inhibiting the formation of PVDF-HFP crystals. The 16.67 wt% PVDF-HFP composition exhibits reduced crystallinity and increased amorphous content, as evidenced by the disappearance of the melting peak in the DSC thermogram. The blends had much better conductivity, according to electrochemical impedance spectroscopy. The 100:20 (PMMA: PVDF-HFP) composition had a high of 3.62 & times; 10-7 S/cm. This improvement is because the polar PMMA and piezoelectric PVDF-HFP work together better, the structure is better arranged, and the segments can move around more easily. The optimized 16.67 wt% PVDF-HFP composition has different thermal transitions, measurable polymer conductivity, and improved dielectric properties, which shows that its structure-property characteristics depend on its composition.

The films of PVC were prepared by mixing ethylene carbonate (EC) and by employing the solution casting method. The samples that were prepared were characterized for their structural, morphological, functional, and electrical properties by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and AC impedance analysis, respectively. The XRD patterns illustrated that the pure PVC was having sharp crystalline broad peaks at 17.45° and 19.25° which gradually disappeared with the increasing concentration of EC showing a gradual transition to the amorphous nature. The best combination PVC with EC showed the highest amorphous character with the suppressed crystalline peaks, which is indicative of the good miscibility of PVC and EC. The SEM results revealed that the surface of PVC with EC was smooth and homogeneous. The FTIR spectra showed significant polymer-plasticizer interactions in the form of O-H and C=O stretching vibrations and also decreased C-Cl intensity indicating the disruption of PVC crystalline domains. AC conductivity studies revealed that pure PVC had the lowest conductivity (σ = 3.82 × 10⁻⁸ S/cm), however, the conductivity increased enormously with the addition of the EC. The PVC with 30% EC had the lowest resistance and highest conductivity due to increased chain flexibility and free volume, however, the performance was degraded by the excess EC.

Sodium- ion conducting solid polymer electrolytes are considered a safe and sustainable alternative to liquid electrolytes for next- generation rechargeable batteries. In this work, nanocomposite membranes based on Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly (vinyl chloride) (PVC) blend complexed with sodium tetrafluoroborate (NaBF4) and reinforced with TiO2 nanoparticles were fabricated by solution casting method. The recorded X-ray diffraction (XRD) patterns of these films revealed a significant reduction in polymer crystallinity upon the incorporation of salt and nanofiller, indicating enhanced amorphous character, which is favourable for ion transport. Scanning electron microscopy (SEM) confirmed a uniform dispersion of TiO2 and the formation of a porous, interconnected microstructure at intermediate TiO2 loadings. At higher filler concentrations, agglomeration and reduced porosity were observed, correlating with diminished structural uniformity. In brief, the findings confirm that TiO2 nanofillers are capable of directing the morphology and chain packing of PVDF-HFP/PVC/NaBF4 electrolytes, thereby paving the way for their use as solid electrolytes in sodium-ion energy storage systems.

In this study, CuO–ZnO nanocomposites were synthesized using wood apple shell extract as a green, non-toxic reducing and stabilizing agent. The nanocomposites were comprehensively characterized using XRD, FT-IR, UV-DRS, PL, SEM, and EDAX to investigate their structural, optical, and morphological properties. UV-DRS analysis revealed a bandgap energy reduction to 2.86 eV, favoring enhanced visible-light absorption. The photocatalytic performance of the CuO–ZnO nanocomposite was evaluated for the degradation of methylene blue (MB) and rhodamine B (RhB) under sunlight irradiation. The catalyst exhibited exceptional degradation efficiencies, achieving 98.11 ± 1.91

This work presents the development of polymer nanocomposite electrolytes tailored for dye-sensitized solar cells (DSSCs). Thin films were fabricated by incorporating aluminum oxide (Al2O3) nanoparticles (2 and 4 wt.%) into a poly(ethylene oxide)-poly(methyl methacrylate) (PEO-PMMA) matrix via solution casting. Structural and spectroscopic analyses (XRD, FTIR) confirmed enhanced amorphization and robust polymer-nanofiller interactions, leading to improved ionic conductivity. UV-Vis spectroscopy revealed bandgap modifications, reflecting nanoparticle-induced change in the electronic structure. Cyclic voltammetry of the 4 wt.% Al2O3 film (PEPM824) demonstrated stable redox behavior and efficient ion transport. When integrated into DSSCs, PEPM824 achieved a power conversion efficiency of 1.89%, outperforming the pristine system. These results highlight the potential of PEO-PMMA/Al2O3 nanocomposites as promising, flexible, and high-performance electrolytes for next-generation energy conversion devices.

An In situ oxidative chemical polymerization technique was used to prepare thin films of PPY, PVA, and PPY-PVA blend doped with variable concentrations of TiO2 fine- and nano-particles further investigated by X-ray diffractometer (XRD) and impedance spectrometer to study structural, dielectric, and AC conducting behavior. XRD spectra established that sharp and high intense peaks of PPY-PVA- fine TiO2 films indicated more crystallinity, which might be due to higher compactness and modification in interplanar spacing. Dielectric plots revealed that PPY-PVA-nano TiO2 films exhibited higher dielectric constants and lower dielectric loss compared to films of PPY-PVA- fine TiO2 in shorter frequency region, suggesting that these films are more suitable for charge storage devices. Conductivity plots revealed that AC conductivity of pure PPY was low (4.8 × 10−3 S cm−1 at 313 0 K) and was increased to 5.3 × 10−3 S cm−1 by addition of PVA. AC conductivities of PPY-PVA-nano TiO2 thin films are relatively higher (7.43 × 10−3 S cm−1 to 1.14 × 10−2 S cm−1) than PPY-PVA-fine TiO2 films (6.35 × 10−3 to 9.78 × 10−3 S cm−1) with increasing frequency and temperature, which could be due to large surface area to volume ratio of nano-size dopant. This suggests that PPY-PVA-nano TiO2 thin films may be used for sensing various gasses.

To investigate a polymer blend membrane PVDF-HFP (Poly (vinylidene fluoride-co-hexafluoropropylene)) mixed with PVC (Polyvinyl chloride) membrane is prepared using the solution casting method. To find the miscibility of two polymers PVDF-HFP and PVC have been studied by X-RD. To comprehend the optical behaviour of blend polymers, their UV absorption and extinction coefficient were used. It is useful to describe how strongly chemical species absorbs light. Electrochemical impedance spectra of blended polymer reveal interaction between two polymers and conductivity was measured. The optimum concentration of PVC: PVDF-HFP (75:25) blend polymer shows the maximum electrical conductivity value is σ = 7.3347 × 10−09 Scm−1.

The fabrication of polymer blend membranes by using poly (vinylidene fluoride- hexaflouoropropyline) (PVdF-HFP) with selective weight ratios of poly (ethylene oxide) (PEO) by deploying solution-cast method. The morphological, structural, thermal studies of polymer blend membranes were investigated employing X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC). The SEM results revealed that the surface profile of blended films becomes smoother with considerable pores due to mixing of PEO to PVdF-HFP, and indicating enhancement in amorphous nature. The dominance of PEO on PVdF-HFP is clearly seen by diminishing of crystalline peaks in XRD crystallography. The FTIR studies evidenced dramatic changes in various band positions due to well cross-linking between PVdF-HFP and PEO. DSC study revealed the lowest melting temperature in blend films which clearly indicates miscibility between PVdF-HFP and PEO owing to cross-linking.

In order to enhance storage capacity and prevent electrical short circuits in electrochemical storage devices, it is essential and challenging to design and build Lithium ion batteries with flexible solid polymer electrolyte possessing strong ionic conductivity. This study details the use of solution-cast technique to create nano composite doped lithium solid polymer electrolytes ( n -LSPEs), from polymer complex of poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), polyethylene oxide (PEO), and Lithium trifluoromethanesulfonate (LiCF 3 SO 3 ), with nano ZrO 2 ( n -ZrO 2 ). Electrochemical impedance spectroscopy (EIS) was utilised to describe the ionic conductivity values in presence of alternating fields. The ionic conductivity of n -LSPEs are enhanced nearly four times (1.54 × 10 ─1 mS/cm to 5.996 × 10 ─1 mS/cm) due to addition of n -ZrO 2 . By incorporating chronoamperometry (CA) and cyclic voltammetry (CV), we were able to analyse the transference number, ionic strength, and the accumulation of charge carriers in optimized n -LSPE membrane. Scanning electron microscope (SEM) images of n -LSPE membranes reveal a structure that is consistent with interconnecting pores between the polymer complex and the nano filler. The stable monoclinic phase of n -ZrO 2 interaction with polymer segmental motion was confirmed by X-ray diffraction (XRD). By examining Fourier transform infrared spectroscopy (FTIR), we performed a quick analysis of the complexation of functional group investigations, bond length and force constant calculations, interaction of functional groups of n -LSPE films. Our FESD's discharge characteristics were investigated at 4.8 mA average discharge current for 25 hours, as indicated by a 0.04C rating.

Poly(vinylidene co-hexafluoropropylene) (PVDF-HFP) has gained considerable attention as an alternative to the commercial separators in energy devices. NiO nanofiller-based solid polymer composite electrolytic thin membranes (PVDF-co-HFP:Mg(ClO4)(2):NiO) were prepared using solid PVDF-co-HFP copolymer and Mg(ClO4)(2)via the solution-casting method. The obtained thin membranes were structurally characterized by FTIR, the porosity of the membrane was analyzed by scanning electron microscope (SEM) and an optimum SEM micrograph of 20.0 mu m magnification was taken to analyze the exact porous diameter distribution frequency. XRD analysis was used to confirm the physical state of the PVDF-co-HFP membrane and the composite membrane of (PVDF-co-HFP:Mg(ClO4)(2):NiO). Structural studies related to XRD peaks were broadened at an optimized Mg(ClO4)(2) salt concentration, confirming the presence of maximum amorphous content in the PVDF-co-HFP:Mg(ClO4)(2) composite. Using the Nyquist plot, the ohmic resistance (R-Omega), polarization resistance (R-P), and Warburg impedance (W) were determined to be at their lowest values for an optimum concentration of NiO nanofiller in the PVDF-co-HFP:Mg(ClO4)(2):NiO composite. The homogeneous dispersion of the nanofiller significantly improved the contact between electrode and electrolyte interfaces, resulting in high ionic conductivity. The DC and AC ionic conductivities of the pure PVDF-co-HFP and composite membrane of (PVDF-co-HFP:Mg(ClO4)(2):NiO) was studied by electrochemical impedance spectroscopy (EIS), and the optimum ionic conductivity was estimated as sigma = 4:511. 10(-3) Scm(-1). A spin-coating technique was employed to prepare dye-sensitized solar cells (DSSC). The fill factor (FF = 0:858561799) and efficiency (eta%) = 11.12532 were estimated from the J-V graph. [GRAPHICS]

Design and development of lithium ion batteries with flexible solid polymer electrolyte along with high ionic conductivity is crucial and challenging so as to protect from electrical short circuits within electrochemical devices. The present research work describes the fabrication of lithium based solid polymer electrolytes (LSPEs) using polymer blends of poly (vinylidene fluoride- hexafluoropropylene) (PVdF-HFP), poly (ethylene oxide) (PEO) with selective weight ratios of lithium trifluoromethanesulfonate (LiCF3SO3) salt by using solution-cast approach. The scanning electron microscopy (SEM) exposed morphology of LSPE membranes depicts crosslinking of polymer network with salt elevates strong dissociation behavior of LiCF3SO3. The amorphous behavior of LSPEs explored using X-ray diffraction (XRD) crystallographs clearly accommodates reduction of average crystallite size from 10(6) m to 10(9) m. The complexation studies, bond length and force constants calculations, interaction of ions, ionic pairs and aggregates of LiCF3SO3 in LSPE films were briefly analyzed using Fourier transform infrared spectroscopy (FTIR). IR modes correspond to [delta(s) (SO3)], [upsilon(as) (SO3)], [upsilon(as) (CF3)], and amorphous phase of PVdF-HFP results in complexation, whereas IR modes correspond to [delta(as) (SO3)], [delta(s) (CF3)], [delta(as) (CF3)], [upsilon(s) (SO3)], C=O and beta-phase of PVdF-HFP attributes ionic pairs and aggregation phenomena. The [upsilon(s) (SO3)] mode contribution toward ionic conductivity was detailed. The ionic conductivity (sigma(ionic)) values were estimated using Electrochemical impedance spectroscopy (EIS). The sigma(ionic) values were enhanced from 10(7) S/cm to 10(4) S/cm as salt concentration increases. Charge accumulation, ionic strength, and transference number analysis of LSPE membranes were investigated using Chronoamperometry and Cyclic Voltammetry. Further, we have fabricated flexible electrochemical storage device (FESD) which are accentuating carriers of smart electronics technology (SET) in terms of foldable and stretchable electronic devices. We have explored discharge characteristics of our FESD with an average discharge current of 3 mA for 25 hours and denoted using 0.04C rating.

The fabrication of nano TiO2 polymer electrolyte of PVDF-HFP: Mg (ClO4)2 polymer matrix deploying solution casting technique. An effect of nano TiO2 with PVDF-HFP: Mg(ClO4)2 was studied by FTIR, and Electrochemical impedance spectroscopy. The FT-IR results revealed the dramatic changes in α, β, γ and δ polymorphous phase transition of –CF-CF- on PVDF-HFP polymer shows fair miscibility and interaction between Mg2+ ion and PVDF-HFP and nano TiO2; when nano TiO2 added to PVDF-HFP: Mg solid polymer electrolyte. The impedance spectroscopy results of PVDF-HFP: Mg(ClO4)2 with nano-TiO2 included revealed that bulk resistance decreased with increasing TiO2 nano filler concentration up to a specific optimum concentration, and then rose with additional increases in TiO2 nano filler concentration. The optimum conductivity was obtained for the PVDF-HFP:Mg(ClO4)2:TiO2(nano) solid polymer electrolyte in the 100:40:12 ratio, and the observed value is in the order of 10−3 Scm−1.

In this paper, solid polymer electrolytes comprising of poly(vinylidene fluoride-co-hexafluoropropylene) and Mg(ClO4)2 were prepared by employing the solution casting technique. The fabricated polymer-salt electrolyte membranes are exposed to XRD, FTIR and SEM studies, which confirm amorphous phase and the presence of interlinked micro-pores promote for easy mobility of Mg2+ ions that enhances ionic conductivity. The real and imaginary parts of dielectric permittivity are illustrated with the Cole–Cole plot. Static dielectric constant $${{\varepsilon }_{s}}$$ , dynamic dielectric constant $${{\varepsilon }_{\infty }}$$ , dielectric strength $${{\Delta }}\varepsilon $$ , dielectric loss (tan δ) and relaxation time τ are determined using the Cole–Cole plot, which attributes fast hopping of ions from one site of the polymer chain to another for optimal concentration of polymer electrolyte. The electrochemical properties, such as cell discharge characteristics and cell stability (cyclic voltammetry), are analyzed to favor an electrochemical membrane for battery applications. The activation energy of all the samples is estimated from the DC conductivity data. The frequency-dependent ionic conductivity follows Jonscher’s power law, and the exponent “n” shows a dominant long-range pathway and diffusion requisite hopping process for ion transport in polymer electrolytes.

Solution casting method was used to prepare the Ethylene Carbonate (EC) doped in NaClO4 salt added PMMA:PEO blend polymer electrolyte thin films. Different characterization techniques such as XRD, SEM, DSC and FTIR were employed to study the effect on structural properties of these prepared thin films. The XRD, SEM and DSC results revealed the dominant presence of amorphous content in PMMA based polymer blend with the addition of PEO, NaClO4 and EC, which functions to enhance in ionic conductivity. FTIR spectra results elucidated that the vibrational band peaks corresponds to PMMA shifted towards lower or higher wave number side in presence of PEO, NaClO4 and EC, which confirms the interaction/complexation between PMMA, PEO polymers with NaClO4 salt and EC plasticizer.

Nano composite polymer electrolytes with different concentrations of ZrO2 nanofillers added in PVDFHFP:Mg(ClO4)2are prepared using classical solution casting technique.The incorporation of ZrO2 nanofillers into the PVDF-HFP: Mg(ClO4)2improved conductivity by making more ions available for conduction. Electrochemical Impedance Spectroscopy was used to investigate the electrical conductivity, ohmic resistance(RX), polarisation resistance(Rp), and Warburg impedance (W) to understand ion transportation behaviour. And the composition-dependent ionic conductivity was determined and the optimum found rion = 6:62 x 10-2SCm-1 at the PSZr12. The nanocomposite polymer electrolyte is used to prepare an electro chemical cell, and its open circuit voltage is found to be1.8 V and its short circuit current is 180 mA. Copyright (c) 2022 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Emerging Trends in Material Science and Technology - 2022.

Abstract The potential effect of nano TiO2 in poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) based polymer electrolyte and their application in a dye sensitized solar cell have been investigated. The solution casting process was used for fabrication of nano TiO2 loaded in Mg 2+ ion based PVDF-HFP solid polymer electrolyte (SPE), and characterized using conductivity, scanning electron microscopy (SEM), X-ray diffraction (XRD) and photovoltaic studies. XRD investigations reveal the broadening of specific peaks, which shows the occurrence of α, β and γ polymorphous phase transitions that commence the amorphous character and ion mobility. The SEM pictures revealed an interconnecting network of micro-porous nature, and an average diameter of the pores of ∼0.38 µm was obtained by using Gaussian curve fitting. Ion transport is facilitated by the high concentration of pores, which is responsible for the efficient absorption of a significant amount of electrolyte. The photovoltaic characteristics of dye sensitized solar cell (DSSC) estimated efficiency (η) is 9.9999%, and the fill factor is 0.84. Furthermore, the stability performance of the nanocomposite polymer electrolyte was improved and sufficient for use over an extended length of time, suggesting potential applications as a separator in solid state ionic conductors.

A solution-cast process was used to prepare pure poly (methyl methacrylate) (PMMA), and pure poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), their blend, and different weight percentages of sodium per chlorate (NaClO4) salt added to PMMA: PVdF-HFP polymer blend electrolyte thin films. The polymer electrolyte film was prepared using the solution cast process, which involves combining sodium per chlorate (NaClO4) ionic slat with poly (methyl methacrylate) (PMMA) and pure poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) blended polymer. These films have been characterized systematically using different experimental techniques to investigate structural, morphological, thermal, and conductivity properties. The degree of crystallinity and porous microstructure of all the thin films were determined by XRD and SEM data and revealed that higher content of the amorphous nature was noticed at higher NaClO4 salt concentration in PMMA:PVdF-HFP polymer blend. When NaClO4 salt was added to a PMMA:PVdF-HFP polymer blend, fair complexation/interaction between polymers and salt was observed.In DSC curves of PMMA and PVdF-HFP polymers, a sharp melting temperature (Tm) was seen, which diminished when NaClO4 salt was added, showing that its amorphous nature had risen to prominence. The ionic conductivity of NaClO4 salt added PMMA:PVdF-HFP polymer blend electrolyte has been investigated, with an optimal value found to be1.55382 x 10-4S/cm at 40% NaClO4 salt. Electrochemical cells have been fabricated and investigated its characteristics in the configuration of Na/[PMMA:PVdF-HFP: NaClO4]/(I2:C).