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In large-scale all-solid-state storage technologies, solid polymer electrolytes (SPEs) provide greater safety and longer cycle life than traditional liquid or gel polymer electrolytes. Polymer electrolytes (PEs) derived from biopolymers have been intensively explored for use in electrochemical devices due to their great flexibility, low cost, and environmental sustainability. However, biopolymer-based electrolytes cannot meet the expectations of practical applications at room temperature due to their low ionic conductivity. Over the years, improving the performance of this class of electrolytes has been the focus of intense research and development, notably polymer blending, plasticization, and structural functionalization. Here, we investigate the performance of an all-biopolymer solid electrolytes based on a methylcellulose-pectin blend doped with potassium phosphate. FESEM micrographs, as well as the shifting and changing intensity of FTIR bands in the electrolyte specimens confirm the polyblend homogeneity with no phase separation. The increased amorphous fraction of the composite polymer electrolytes (CPEs) is seen in the XRD and DSC patterns of the plasticized and unplasticized samples. Impendence studies performed on the system recorded a maximum ionic conductivity of 1 × 10–5Scm−1by doping with 50 wt.% K3PO4. This value further increased to 5.9 × 10–4Scm−1upon adding 25 wt.% EC to the polymer system. This sample also possesses an electrochemical stability window of 4.24 V and an ion transference number of 0.95.

This research study aimed to remove chromium (Cr6+) from aqueous and industrial effluent by natural Gallus gallus domesticus eggshell waste magnetized with Fe3O4nanoparticles (MES). A literature survey showed that the sorption of Cr on the modified magnetite form of this biomass had not been explored before. Structure, morphology, functional groups, and thermal stability of the prepared modified biosorbent were characterized by scanning electron microscopy, X-ray diffraction pattern, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The results of the characterization study confirmed the suitability of Cr adsorption on the proposed adsorbent. The optimization studies were performed to measure the suitable conditions for the adsorption process. The most suitable pH for maximum chromium adsorption by MES was 2. The contact time for maximum adsorption was noted to be 30 min, and the most suitable temperature was found to be 20°C. It was observed that MES showed 95% removal of Cr. The kinetics data for MES followed the pseudo-first-order kinetic model, while the intraparticle diffusion played a significant part in the rate-controlling step. The results described the pseudo-first-order kinetic model for Cr adsorption by MES, with the highest value of correlation coefficient R2= 0.864. The equilibrium for adsorption data was best described by Langmuir isotherm. For the thermodynamic process, ΔG°, ΔH°, and ΔS° were calculated, the value of ΔH and ΔS was –34.622 and –0.11 kJ/mol K, respectively, and found that adsorption of Cr was spontaneous and exothermic. The suitability of MES in industrial effluent was also carried out that offers a green, sustainable, cost-effective, and real-world water treatment solution for water purification having Cr from wastewater/industrial effluent.

The advantages of palm kernel shell (PKS) as a renewable and sustainable material for activated carbon production have been explored for various applications such as water treatment, pollutant, pesticide, and heavy metal adsorption. However, the full promises of this material for energy storage devices have not been duly studied. In this research, PKS is physically activated and the effect of particle size on the physical characteristics of the activated char was investigated. Pellet (3 mm), granules (0.4 mm), and powder (0.0075 mm) are the sizes considered in the experiment. The surface morphology, surface area, porosity and functional group at different sized was analyzed. Finally, a suitable particle size was recommended for the electrode material of supercapacitor based on the physical characteristics of the activated carbon.

Para-Toluene sulfonic acid doped polyaniline (PANI), PANI/chitosan composites, PANI/reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide have synthesised via oxidative polymerisation of aniline by Ammonium peroxydisulfate (APS). FTIR, XRD, FESEM and UV-VIS techniques were performed for the confirmation of the successful synthesis. The fundamental optical parameters such as, complex refractive index, complex dielectric constants and optical conductivity of the PANI and the composites were investigated in the UV-VIS-NIR range. The results show a clear dependence on the constituent component such as sulphur as well as the absorbance values of the polymers. This study would therefore serve as initial solution to the scarcity of studies on the optical contants of p-toluene sulfonic acid doped polyaniline and its composites that could have many potential electrical, optical and optoelectronic applications.

The increasing energy consumption in modern society requires long-term energy storage technology. The main problem for a sustainable energy storage system is energy optimization and power density. The vanadium copper sulfide (VCuS) was hydrothermally synthesized in this study. The electrochemical activity of the VCuS was studied with the three-cell configuration, which demonstrated a maximum capacity of 475C/g (at 1.0 A/g), higher than VS2and CuS. The surface area for VCuS was 13.65 m2/g, estimated using the BET measurement. The conductivity of VCuS was measured to be 233 mS/cm, while 1 M KOH electrolyte shows maximum conductivity of 206 mS/cm. The supercapattery (VCuS//AC) delivers an excellent specific capacity of 163C/g having a current density of 1.0 A/g. The VCuS//AC can provide energy of 34.5 Wh/kg at 800 W/kg power density (at 1.0 A/g). Additionally, the VCuS//AC durability test measured capacity retention after subjecting it to 10,000 cycles. The VCuS//AC displayed excellent cycling stability of 80 % after 10,000 cycle repetitions.

Exhaled breath (EB) contains thousands of volatile and nonvolatile biomolecules. EB analysis is non-invasive and convenient to patients than blood or urine tests. The exhaled biomolecules have long been studied and recognized to have some potential biomarkers for diagnosis of diseases, evaluation of metabolic disorders and monitoring drug efficiency. For instance, Biomarkers such as exhaled hydrogen peroxide (H2O2) and exhaled nitric oxide are associated with inflammatory lung diseases, ammonia is used as a biomarker for kidney diseases and exhaled acetone is related to glucose concentration in blood and so it is used for diabetes diagnosis. H2O2 concentration in EB increases with the severity of lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), and adult respiratory distress syndrome (ARDS). Different methods are used to measure H2O2 in exhaled breath condensate (EBC). In EBC the EB is collected in a condensate unit and then H2O2 concentration in the collected sample is detected using titrimetric, spectrophotometry, fluorescence, chemiluminescence and electrochemical sensors. Recently, some works have been done to measure the concentration of H2O2 in its vapor phase without a need for condensation units. The aim of this paper is to review and summarize the current methods being used to measure the concentration of H2O2 in EB to identify inflammatory lung diseases, and to discuss the advantages and disadvantages of these methods

Micro-analytical based sensors with complex biomatrices such as blood, urine, or saliva are of increasing interest in health-care sector because of their sensitivity, selectively and simplicity. A modified carbon electrode with hydroxyapatite (HAp) and Bismuth (II) was developed to detect Pb2+ concentration in blood sera from healthy persons. Square wave anodic stripping voltammetry was used for the detection of Pb2+ by the interacting capability of the Bi film and HAp on the electrode surface with the optimised parameters of deposition time 240sec, deposition potential –1.0 V in 0.1M acetate buffer followed by square wave potential scan from-1.0 V to-0.2V. Bi film deposited HAp-CME showed attractive electrochemical characteristics with high sensitivity for Pb2+. Clear current peaks for different Pb2+ concentrations were observed around-0.55V, with favourable signal-to-background ratio, and comparatively free from oxygen interferences.

Boldenone (androsta-1,4-dien-17-ol-3-one), an androgenic anabolic steroid (AAS), is intensively used for growth promoting purposes in animals for meat production and as a performance enhancer in athletics. Its use is prohibited either in animals intended for human consumption or directly for humans, as most of the anabolic steroids are completely metabolized. The current method of detection, such as the mass spectrometry coupled with gas chromatography or liquid chromatography are sensitive, highly specific and are popular methods of detection. However, these have some intrinsic drawbacks such as the requirements of complicated and expensive instrumentation, time consuming and production of narrow detection limits. Boldenone and its metabolites in urine samples of animal matrices can be detected by means of electrochemical methods using tunable and chemically-modified screen-printed carbon electrodes (SPCEs).

This paper is about CMOS MEMS resonant magnetic field sensor in which differential electrostatic actuation, capacitive sensing, resonant frequency, quality factor and sensitivity of interdigitated comb resonator is investigated. Information is embedded in the output signal frequency because it is robust against the interference from other sources during transmission. At damping ratio of 0.0001, resonant frequency of the comb resonator is 4.35 kHz with quality factor 5000 and amplitude 18.45 μm. Sensitivity of the device towards external magnetic field is 9.455 mHz/nT which is 10,000 times improved than recently published data.

This paper presents an impact-based frequency increased electromagnetic vibration energy harvester to scavenge energy in a low frequency environment. To realize the novel impact based frequency up-conversion mechanism, a coil has been elastically anchored with a platform on which four permanent magnets are arranged in such a way that a strong closed magnetic flux path, linking the coil, is formed. The proposed scavenger has two dynamics of motion. The first phase is a low frequency oscillation to absorb energy from ambient vibration during which both the coil and magnet act as proof mass and move collectively. The increased proof mass ensures maximization of absorbed energy. After crossing a certain clearance, the platform containing magnetic setup rigidly and supporting the coil elastically, collides with a rigid stopper and bounces back. As a result of this mechanical impact a high frequency oscillation is setup in the coil relative to the magnets during which energy is transferred to electrical domain by electromagnetic induction. A macro-prototype has been build to prove the proposed concept. Initial test results show that the proposed harvester generates a peak voltage of 1 volt across a load of 220 Ω at an excitation frequency of 5 Hz which corresponds to a peak power of 4.5 mW and average power of 660 µW.

•Explores the complementary advantages of the lignocellulose chemistry of palm waste as composite material for activated carbon preparation.•Extensive proximate, ultimate, and physiochemical characterization of the prepared materials•Fabricate a real supercapacitor using the prepared activated carbon and solid-state electrolyte.•Electrochemical characterization of the prepared supercapacitors were tested and compared with recent results in literature.