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The main objective of this study was to banana waste-derived activated carbon (BWAC) make a high pore surface area was prepared and composited with Fe

Research on supercapattery has been rising as the state of the art of modern energy storage devices because of its excellent efficiency in terms of power and energy density. In this aspect, layered materials supply better electrochemical attributes, but inadequacy in rate performance, which is the key factor of energy storage devices, forbids its wide application. Herein, we report a simple method of α phase Co2P2O7 synthesis and evaluated its performance by varying the calcination temperature. The electrochemical performance of C550, C650 and C750 was examined in a three-electrode cell configuration utilizing 1 M KOH electrolyte. Since the sample C750 demonstrated the high electrochemical performance, it was further examined in a two-electrode system for the hybrid device. The assembled hybrid device renders a high specific capacity (126.5 C/g) and energy density (23.8 Wh kg−1 @ a power density of 575.3 W kg−1) with good cycling stability (specific capacitance retention of 79% over 5000 cycles). The improved electrochemical performance is attributed to the augmented redox sites with short diffusion pathways of nanoparticles.

A simple wet impregnation approach had been used to the successful preparation of different weight percentages of strontium/niobium doped Er2O3 nanoparticles. The X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), high resolution transmission electron microscope (HR-TEM), Fourier transformed infrared spectroscopy (FTIR), and UV-visible (UV) spectroscopy was used to analyze the samples as they were prepared. With Sr and Nb doping at Er2O3 nanoparticles, the XRD patterns intensity was shifted, and its positioning was also shifted as weight percentages of doped were increased. Similarly, the lattice d spacing values were also decreased. According to HR-TEM images, Er2O3 seems to have a two-dimensional hexagonal nanoplate-like structure as well as being a few nm in size. The photocatalytic activities of pristine and Sr/Nb doped samples were evaluated against the methyl orange (MO) and rhodamine B (Rh B) dyes under UV-visible light irradiation. Within seventy-five minutes of UV-Visible light irradiation, the five-weight percentage of Sr doped Er2O3 nanoparticles shows significantly enhanced photocatalytic degradation efficiency against Rh B dye. The synergistic effect of the strong metal-support interaction between the Sr and Er2O3 nanoparticles could be attributed to the improved photocatalytic activity of the prepared samples. The cyclic stability and radical trapping experiments were also investigated against the same reaction conditions.

Huge demands for photocatalytically efficient visible-light-induced catalysts have spurred widespread interest in building adaptable heterojunctions. Here, we used in situ thermal polymerization to synthesise the Z-scheme Bi2O3/g-C3N4 heterojunction. The optical, structural, chemical, compositional and photocatalytic behaviours of the samples were analysed through various analytical techniques and photocatalytic methylene blue (MB) dye degradation reaction. Among the various ratios of Bi2O3/g-C3N4 heterojunction composites, the 1:1 ratio showed improved visible-light-induced catalytic activity, which attained 91.2% degradation efficiency after 120 min of visible-light exposure. The dye degradation efficiency was calculated under various environmental conditions by varying the dye concentration, solution pH and catalyst dosage. A improved Z-scheme photocatalytic mechanism was proposed in light of the results. A potential mechanism was suggested to explain the photocatalytic activity, and trapping experiments supported it. Last but not least, this strategy might be helpful to prepare the heterojunction photocatalyst for the degradation of organic pigments.

Fabrication of layered triple hydroxides (LTH) is a typical and remarkable approach to produce new functionalities passionately investigated for photocatalytic removal of organic pollutants from industrial wastewater. The hydrothermal method was used to prepare different weight percentages of yttrium (Y) doped NiMgAl LTH. The structural, functional, optical, and morphological properties of the prepared samples were investigated using X-ray diffraction, Fourier transformed-infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, and scanning electron microscopy. The photocatalytic degradation of the different percentages of Y-doped LTH samples were assessed through the photocatalytic degradation of methylene blue dye under the visible light irradiation. When compared to other lower concentrations of Y doping, the photocatalytic degradation efficiency of 1 wt.% Y-doped LTH was higher. Thus, the optimized LTH's improved photocatalytic performance was attributed to increased visible light absorption with low transmission and improved electron-hole separation.

Building a novel electrode with improved electrochemical behaviour has great scope in the area of supercapacitors. In this work, binder-free 1D nanograsses of Ni2P2O7/Co2P2O7 nanocomposites were grown on nickel foam through a simple hydrothermal method at different processing temperatures. A precise examination was carried out to study the influence of the processing temperature on the morphology and electrochemical attributes. Ex situ morphological pictures confirmed the reliance of structure on the hydrothermal temperature and the obtained one-dimensional morphology encouraged ion interaction through short channels. The patterned nanograsses were grown at 140 °C with uniform interspacing and exhibited better electrochemical performance due to short, diffusive 1D pathways. Using the power law, the capacitive parts of the total capacitance were elucidated. The better electrochemical performance from charge–discharge indicates that the binder-free NiP2O7/CoP2O7 1D nanograsses would be an appropriate cathode for an efficient hybrid capacitor. The optimized electrode as the cathode in the device showed better energy density and long-lasting cycle life (80% capacity retention after 2000 cycles). Our outcomes indicate that the Ni2P2O7/Co2P2O7 1D nanograss pattern has good potential for use as a cathode for hybrid supercapacitors.

Rational design of organic-inorganic heterojunction photocatalyst has become a research hotspot of recent researchers due to their abundance and cost effectivity. Herein, we present the integrated photocatalyst carbon dot (CD) decorated on g-C3N4/AgCl heterojunction synthesized by simple impregnation method. The primary confirmation for the as-prepared samples has been carried out by various characterization techniques. From the obtained results, the ternary nanocomposite demonstrated a prominent photocatalytic activity which was almost 10 and 51 fold higher than pure g-C3N4 in the degradation of organic dyes. The reasons behind the improved efficiency are (i) The introduced CD facilitates broader absorption in the visible region because of π-conjugated CDs and provide favorable electron kinetics by creating trap states at the CD/g-C3N4 interface. (ii) The AgCl acts as an electron sinker and reduce the carrier’s recombination. To justify the photocatalytic activity, a possible mechanism was proposed and verified by trapping experiments. Finally, this approach could be a new one in an organic-inorganic hybrid photocatalyst for the degradation of organic dyes.

Enormous research activities have been accomplished to evolve improved cathode for advanced Li-ion-based devices. In this article, we account the preparation of spinel LiMn2O4 synthesized b...

Quantum dots (QDs) and their physiochemical modification according to different photonic applications are discussed in this chapter. The utilization of quantum dots as photoactive materials in numerous applications demands its blend with different materials which in turn plays significant functions in separation and transport of charged particles. Attaining a better interfacial region between electronically conjugated layers is a critical parameter to improve efficiency in photodetectors, photovoltaic applications, and so on.

Developing a novel electrode material with better electrochemical behavior and extended cyclability is a major issue in the field of hybrid capacitors. In this work, we propose a novel strategy for...

Silver nanoparticle (AgNPs) dominates in materials and biomedical fields owing to various properties and beneficial characters. To date, the biosynthesis of silver nanoparticles (AgNPs) is more appreciated due to their harmless behavior and character. In this study, we biosynthesized AgNPs using extracts of Citrus medica, Tagetes lemmonii, and Tarenna asiatica as a reducing and capping agent. The Ultra Violet-visible (UV–vis), Fourier transform infrared spectroscopy (FTIR), and X-Ray Diffraction (XRD) analyses revealed the active metabolites and crystalline structure of the three plants responsible for the biogenic reduction and capping of the AgNPs. On the other hand, the Scanning Electron Microscopy (SEM) showed that the AgNPs assisted by T. asiatica were cuboid in structure, whereas AgNPs assisted by T. lemmonii and C. medica were spherical. Additionally, the larvicidal activities of these samples were also evaluated. The observed LC50 values performed the larvicidal potential of the three plants assisted AgNPs against Aedes aegypti in the order of T. lemmonii-Ag NPs > C. medica-Ag NPs > T. asiatica-Ag NPs. In summary, all three plants, which could effectively reduce Ag+ and cap the AgNPs forming efficient nanoparticles, can inhibit the development of A. aegypti.

Chikungunya, dengue, Zika, malaria, Japanese encephalitis, filariasis, West Nile, etc. are mosquito transmitted diseases that have killed millions of people worldwide, and millions of people are at risk of these diseases. Control of the mosquitoes, such as Aedes aegypti and Culex quinquefasciatus, is challenging due to their development of resistance to synthetic insecticides. The habitats of the young mosquitoes are also the habitats for foodborne pathogens like Staphylococcus aureus (MTCC96) and Serratia marcescens (MTCC4822). The present study was aimed at synthesizing eco-friendly green nanoparticles using Dillenia indica leaf broth and analyzing its efficacy in controlling the vector mosquitoes A. aegypti and C. quinquefasciatus, as well as the microbial pathogens St. aureus and Se. marcescens. The formation of selenium nanoparticles (SeNps) was confirmed using UV-Vis spectroscopy (absorption peak at 383.00 nm), Fourier transform infrared radiation (FTIR spectrum peaks at 3177, 2114, 1614, 1502, 1340, 1097, 901, 705, and 508 cm&minus, 1), X-ray diffraction (diffraction peaks at 23.3 (100), 29.6 (101), 43.5 (012), and 50.05 (201)), and scanning electron microscopy (oval shaped). The size of the nanoparticles and their stability were analyzed using dynamic light scattering (Z-Average value of 248.0 nm) and zeta potential (&minus, 13.2 mV). The SeNps disorganized the epithelial layers and have broken the peritrophic membrane. Histopathological changes were also observed in the midgut and caeca regions of the SeNPs treated A. aegypti and C. quinquefasciatus larvae. The SeNps were also active on both the bacterial species showing strong inhibitory zones. The present results will explain the ability of SeNps in controlling the mosquitoes as well as the bacteria and will contribute to the development of multi potent eco-friendly compounds.