UV Diffuse Reflectance Spectroscopy Research Articles

Tuning the optical property of titania nanotubes array using CdS microemulsion sensitization for enhanced photocatalytic activity

Titania (TiO2) is a well-known photocatalyst in material science. However, it only works in the UV(Ultra violet) range of the spectrum(Eg = 3.2eV). The doping approach allows TiO2 photocatalysis to function in the visible region.Cadmium sulphide(CdS) was utilized as a dopant to maximize the quantity of visible light passing through, as its bandgap was just 2.4eV. Material manipulation at the nanoscale can have many distinct outcomes. Titania nanotubesarray(TiNT)was created by anodization, and CdS quantum dots were made by microemulsion technique and integrated into TiNT. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to study morphology. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to determine the composition. UV-diffuse reflectance (UV-DRS) spectroscopy was used for photocatalytic studies. Photocatalytic methyl orange (MO) breakdown and photocatalytic hydrogen evolution were also proven under visible light. According to the study, the CdS/TiNT nanotubes array has more photocatalytic power than pure TiNT. Based on the findings, CdS quantum dots could get into the nanotubes, making them perfect heterostructures for all visible photocatalysis.

Efficient magnetic and antibacterial properties of CdO/ZnO nanocomposites prepared via facile hydrothermal method

The effect of molar composition on the efficiency of antibacterial and magnetic properties of binary transition metal oxide nanocomposites synthesized using pH optimized hydrothermal method is reported. Its response to X-ray diffraction confirmed the crystallinity of nanocomposites. The average crystallite size is observed to be 27.37 nm, 30.21 nm and 32.3 nm for 1:1, 2:1 and 1:2 molar ratioed CdO/ZnO nanocomposites respectively. FT-IR spectroscopy revealed the presence of moisture and other functional groups, which is further confirmed the Thermogravimetric analysis showing approximately 1.5% of thermal decomposition within 200 °C in all composition. The synthesized composites are characterized for surface morphology using High-resolution scanning electron microscopy and Energy dispersive X-ray analysis showed mixed nanorods, nanotubes and spheroid structures. The optical band gap of proposed nanocomposites is characterized by UV-diffused reflectance spectroscopy showing the variation of optical band gap confirming the change in a molar proportion of CdO/ZnO nanocomposites particles. Investigation on magnetic properties displayed its paramagnetic behavior by illustrating the hysteresis curves of all nanocomposites. The antibacterial activities of proposed nanocomposites investigated for both Gram-positive and Gram-negative bacteria showed its efficiency towards antibacterial application.

Development of hexagonal ZnO nanodisks for potential catalytic reduction of p-nitrophenol

Hexagonal ZnO nanodisks (hZnO Nds) were synthesized via chemical precipitation and characterized by powder X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-diffuse reflectance spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). Results of SEM, EDX and XRD showed that synthesized hZnO Nds has a length of ∼300 nm, porous with pore size of ∼50 nm along with areas that possessed relatively smooth surface, highly pure and crystalline nature. The catalytic reduction performance of hZnO Nds against p-nitrophenol was quantified by UV–visible spectrophotometry in aqueous medium in the presence of sodium borohydride (NaBH4). The complete hZnO Nds based catalytic reduction of p-nitrophenol (100%) occurred within 45 min. The hZnO Nds based catalytic reduction of p-nitrophenol exhibited a significant response, suggesting low reduction limit and good selectivity.

Effect of Europium, Yttrium and Lutetium Doping on the Photocatalytic Property of CeO2 Nanoparticles in the Reduction of p‐nitrophenol under Visible Light

AbstractThe current study focuses on the photocatalytic reduction of p‐nitrophenol using Europium, Yttrium and Lutetium doped Cerium oxide (CeO2) nanoparticles which were synthesized via chemical precipitation method. The synthesized nanoparticles were subjected to characterization using different analytical tools to confirm the formation of nanoparticles. They were characterized using X‐Ray diffraction (XRD) studies, Fourier Transform‐Infrared spectroscopy (FT‐IR), High resolution Scanning electron microscopy (HRSEM), High resolution Transmission electron microscopy (HRTEM), Energy dispersive X‐ray analysis (EDAX), X‐ray photoelectron spectroscopy (XPS), and UV‐Diffuse reflectance spectroscopy (UV‐DRS) studies. The synthesized rare earth nanomaterials were successfully applied for the photoreduction of the organic pollutant p‐nitrophenol with the addition of NaBH4 as reducing agent using 300 W Xenon lamp. The addition of the synthesized photocatalyst enhanced the reduction ability of NaBH4 in reducing p‐nitrophenol to p‐aminophenol. The results confirmed the superior photocatalytic activity of Lu0.05CeO2 compared to the other rare earth doped photocatalysts. The time taken by Lu0.05CeO2 photocatalyst for the complete reduction of p‐nitrophenol was 45 min and was found to be 96 % efficient in the reduction of 0.5 mM p‐nitrophenol to p‐aminophenol compared to the other photocatalysts.

Sol-Gel Synthesis of Multifunctional Bismuth Ferrite Nanostructures: Effect of Heating Conditions on their Photocatalytic Activity

Bismuth ferrite (BiFeO3) is a multifunctional perovskite material well-known for its lead-free chemistry, multiferroic properties at room temperature, photovoltaic properties, and photocatalytic activity. BiFeO3 nanostructures were synthesized using sol-gel method by varying annealing temperature and annealing rate. The formation of phase-pure BiFeO3 was confirmed using X-ray diffraction and Raman spectroscopy.Using scanning electron microscopy, the size of BiFeO3nanostructures was evaluated to be around 100-500 nm depending on the annealing parameters. The bandgap of the synthesized nanostructures was estimated to be 2.18-2.26 eV, with UV diffuse reflectance spectroscopy. The photocatalytic activity was assessed by the degradation of malachite green dye under visible light irradiation and their correlation with heating parameters is discussed in detail.

Hollow TiO2/g-C3N4 nanocomposite for photodegradation of volatile organic carbons under visible-light

Hollow TiO2/g-C3N4 nanocomposite was prepared using solvothermal method. Two-dimensional g-C3N4 nanosheets were coupled with TiO2 hollow spheres at different ratios to investigate the charge-carrier interactions with the aim of enhancing the photocatalytic properties of the nanocomposite. This coupling was systematically examined by scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, photoluminescence, X-ray photoelectron spectroscopy, and UV diffuse reflectance spectroscopy. The prepared nanocomposite was used for the photodegradation of the volatile organic carbons methyl tetra-butyl ether and toluene present in aqueous solution. Elemental analysis and X-ray diffraction revealed a high-purity sample, while the UV diffuse reflectance spectroscopy demonstrated the presence of a well-defined anatase crystal phase for the TiO2 hollow sphere; and the photoluminescence measurements showed an enhancement in visible-light absorbance, with a good reduction in the electron-hole recombination rate. The performance of the nanocomposites in the photocatalytic degradation of toluene under irradiation with visible-light was evaluated. The 20/80% TiO2/g-C3N4 nanocomposite materials showed highest photocatalytic activity for toluene and methyl tetra-butyl ether, achieving a degradation of more than 90%; this is attributed to the interaction between the two surfaces in the TiO2/g-C3N4 nanocomposite, resulting in a higher performance than the individual components.

Investigations of structural, morphological, and optical properties of CoS/Fe3O4 composites

Developing novel multifunctional hybrid magnetic nanocomposites are highly significant in biomedical applications. In this study, a simple one-step hydrothermal route was used to synthesize CoS/Fe3O4 composites. The sample was characterized by XRD, FESEM, EDS, FTIR, and UV-Diffuse Reflectance spectroscopy. XRD studies reveal the successful formation of CoS/Fe3O4 composites. Morphological analysis using FESEM and FTIR data reveals good synergy of the composite material. UV-DRS studies show the composite material's possible use for photothermal applications.

Synthesis of S doped TiO2 (S-TiO2) to enhance photocatalytic degradation of Ciprofloxacin in aqueous solutions under visible light

In this study, the sol-gel method was successfully used to synthesize S-TiO2 for efficient photocatalytic degradation of Ciprofloxacin solution under visible irradiation. These synthesized materials were characterized by various analytical methods such as XRD, SEM-EDX, FT-IR, and UV diffuse reflectance spectroscopy (DRS). XRD, SEM-EDX, and FT-IR confirmed the successful preparation of these materials. The UV-DSR demonstrated that the material has a lower bandgap in comparison with prime TiO2. The photodegradation results reported that the 0.33S-TiO2 had shown high efficiency in the degradation of Ciprofloxacin in comparison with TiO2. The decomposition of 10 mg/L Ciprofloxacin concentration reached approximately 90% for 150 minutes of visible light irradiation at room temperature at pH = 4.

Evaluating the Band Gaps of Semiconductors by Cataluminescence

A rapid and efficient methodology for the evaluation of band gaps of semiconductors is highly desirable to analyze and assess the intrinsic properties and extending application scopes of semiconductor materials. Here, the negative correlation of the cataluminescence (CTL) signal in the presence of H2S and the band gap of Aurivillius-type perovskite oxide Bi4+nFenTi3O12+3n (n = 1-4) was confirmed, where the H2S-induced CTL signal acts as a probe to evaluate the band gaps of semiconductor materials. The related mechanism shows that the thermal energy obtained by heating makes the electrons in the valence band more easily excite into the conduction band of a narrower band gap material and further promotes electron transfer between the gaseous compounds and semiconductor materials, causing acceleration of the catalytic oxide process. In addition, the extensibility was further verified by exploring the layered perovskite containing other insertion structures, including Bi4+nConTi3O12+3n (n = 1-4), Bi5NiTi3O15, and Bi5MnTi3O15, which was also consistent with the results characterized by UV diffuse reflectance spectroscopy. The established CTL probe for band gap evaluation shows rapid response, is simple to operate, and is of low cost, which is expected to become an innovative alternative to the conventional band gap assessment approach.

Synthesis, structural, topographical, optical and luminescence of CeO2/SnO2 2D hexagonal nanostructures

Optical properties of 2D nanostructures are widely attracted due to its tremendous applications. In this work, CeO2/SnO2 nanocomposites with 2D hexagonal nanostructures were synthesized by the wet chemical method using mixed solvent water/ethane-1,2-diol. The properties of the CeO2/SnO2 nanocomposites were characterized by X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), Transmission electron microscopy (TEM), UV-Diffuse Reflectance spectroscopy (UV-DRS) and Photoluminescence (PL) spectroscopy. The TEM images show that the water/ethane-1,2-diol assisted CeO2/SnO2 nanocomposite exhibit formation of uniformly dispersed 2D hexagonal nanostructure. The powder XRD results confirmed the formation of CeO2/SnO2 nanocomposites, further it shows the water/ethane-1,2-diol assisted nanocomposite exhibit low intensity peak which is due to the small particle size. Roomtemperature photoluminescence (RTPL) emission studies indicate that as obtained CeO2/SnO2 2D hexagonal nanostructure have much stronger emission than water/ethanol assisted CeO2/SnO2 nanocomposites. The band gap energies of the samples prepared for water/ethanol and water/ethane-1,2-diol obtained by the tauc plots of (αhυ)2 versus (hυ) curve are 3.21 and 3.22 eV respectively.

Enhanced photocatalytic degradation of organic dyes from aqueous environment using neodymium-doped mesoporous layered double hydroxide

Neodymium-doped Zn–Al layered double hydroxide (Nd/Zn-Al LDH) with excellent photocatalytic activity was prepared by a one-step hydrothermal method. The morphology and physicochemical properties of as-synthesized photocatalysts were well analyzed by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL), UV-diffuse reflectance spectroscopy (UV-DRS), and Brunauer-Emmett-Teller (BET) surface analysis. Doping Nd3+ into Zn–Al LDH enhances the overall catalytic activity of the nanocomposite, like better electron–hole pair separation, increase in interplanar distance, fast electron transfer, and large surface area. The as-prepared nanocomposite shows excellent degradation of three different dyes under visible light irradiation. The degradation efficiency of these dyes follows the order of Congo red > rose Bengal > fast green. Furthermore, liquid chromatography-mass spectrometry (LC-MS) was employed to propose a possible photocatalytic degradation pathway for Congo Red and Rose Bengal dyes by Nd/Zn–Al LDH. With the help of radical trapping experiments, it is revealed that during the photoexcitation process, the primary reactive intermediates are hydroxyl radicals.

Optimization of Energy and Time Variations for Synthesis of N doped TiO2 Nanotube using Microwave-Asssisted Hydrothermal Method

This study aimed to determine the effect of energy and time hydrothermal microwave time variations on the crystal structure and N-TiO2 nanotube photocatalytic activity. The synthesis of N-TiO2 nanotube was performed with the hydrothermal microwave method. The N-TiO2 preparationwas carried out by dissolving ethylenediamine precursor in 80 ml of 96% ethanol and 3 ml TTIP which was reacted at 70 °C for 4 hours. The obtained N-TiO2 was formed into nanotubes used the hydrotermal microwave method in low temperature (180W), medium temperature (360 W), and high temperature (720 W) with time variations of 30 minutes, 1 hour, and 2 hours. The microwave hydrothermal process in this study used 10 M NaOH to form a tubular structure and 0.5 M HCl as an ion exchange. The characterization analysis performed by X-Ray Diffraction, UV-Diffuse Reflectance Spectroscopy, and blue methylene degradation. The results of this study indicate that the variations of time and energy of the microwave hydrothermal method affect the crystal structure of the N-TiO2 nanotubes. The nanotubes structure has been formed at a variety of low energy 2 hours, medium energy 0.5 hours, 1 hour and 2 hours, and high energy 2 hours. Energy and time variations of hydrothermal microwave affect the photocatalytic activity of N-TiO2 nanotubes showed second-order kinetics. The best percentage of degradation produced in the T2 variation is the photocatalyst reaction of 71.89% and the adsorbs reaction of 64.81%.

A facile hydrothermal synthesis of novel CeO2/CdSe and CeO2/CdTe Nanocomposites: Spectroscopic investigations for economically feasible photocatalytic degradation of Congo red dye

The photocatalytic activity of CeO2 nanoparticles in the visible spectrum can be greatly improved via incorporating of narrow band gap semiconductors like CdSe and CdTe into CeO2 structure bringing out a new heterojunction structure to boost the visible-light absorption efficiency. Therefore, CeO2/CdSe and CeO2/CdTe nanocomposites were felicitously fabricated through a simple and effective hydrothermal route without using any expensive surfactant or capping agent keeping a molar ratio of 1:1:1 (Ce:Cd:Se/Te). The as-synthesized materials were identified utilizing different spectroscopic investigation techniques such as X-ray diffraction (XRD), Raman spectroscopy and Solid-state UV-diffuse reflectance spectroscopy (UV-DRS). Transmission electron microscopy (TEM) confirmed the semi-spherical structure of all as-synthesized samples with deposition of CdSe and CdTe particles on CeO2 surface leading to binary composites formation. The specific surface areas (BET) were explored to be 55.2 m2/g and 20.8 m2/g for CeO2/CdSe and CeO2/CdTe nanocomposites, respectively. The photocatalytic performance of CeO2/CdSe and CeO2/CdTe nanocomposites was tested under visible-light irradiation on an aqueous solution of Congo red (CR) dye using an energy-saving lamp (LED). The degree of degradation was monitored by UV–Vis spectroscopy and verified by chemical oxygen demand (COD) studies. The photocatalytic degradation efficiency of CeO2/CdSe nanocomposite (97.3%) was about 3.5 times greater than of bare-CeO2 NPs (28.2%) within only 150 min of irradiation. Photo-induced electrons were found to be the primary active participating species that was verified using the relevant radical scavengers and a clear photocatalytic mechanism was proposed. The recycling test confirmed that CeO2/CdSe is a highly photostable catalyst with four-repeating cycles displaying degradation efficiencies, respectively, at 97.3%, 96.1%, 95.5% and 95.1%. The structural stability of the operated catalyst was confirmed by XRD studies.

Agro and industrial residues: Potential raw materials for photocatalyst development

Contamination by organic effluents is currently one of the most serious environmental problems and, as a result, the elimination of these pollutants has been widely studied, mainly with organic phenolic pollutants. Photocatalysis have been showing an interesting process in order to optimize the conventional wastewater treatments. Thus, agroindustrial waste (exhausted bark acacia) and Ziegler–Natta catalyst slurry waste were used as supports for photocatalysts. The morphology and chemical composition of the catalysts were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and the X-ray photoelectron spectroscopy (XPS). Band-gaps were determined using UV diffuse reflectance spectroscopy (DRS). Multiscale structural characterization, pore analysis and specific surface area were determined by small-angle X-ray scattering (SAXS) and N2 porosimetry 77 K. Zeta potential (ζ) measurements were carried out to verify the stability of catalyst suspensions. The photocatalysts contained Al, Mg, Si and Ti. Metallic content ranged from 0.01 to 0.83 wt%. Ti-samples showed specific surface area between from 27.3 562.30 m g-to 562.30 m² g−1, a band gap energy (2.55–3.65 eV), negative surface potential and the presence of mass and surface fractals. The prepared photocatalytic systems (catalyst with support) were evaluated for phenol photodegradation, where the greatest percentage of phenol degradation was 68.4% under UV-V % under UV–vis radiation, while industrial standard Degussa P25 showed 43.8 % degradation. Therefore, (agro)industrial waste can be used as precursors or catalytic supports of photocatalysts for application in the treatment of wastewater meeting sustainable development.

Superior photocatalytic removal of metamitron and its mixture with Rhodamine B dye using combustion synthesized TiO2 nanomaterial

In this study, photocatalytic degradation of a herbicide, metamitron, was carried out using combustion synthesized nano-TiO2. The synthesized catalyst was characterized using X-ray diffraction, porosimetry and UV-diffuse reflectance spectroscopy. The combustion synthesized catalyst showed lower crystallite size, better surface area and narrower band-gap compared to the commercial TiO2. The effect of catalyst loading, initial concentration of metamitron, pH and presence of inorganic ions on the extent of degradation was studied. The pseudo first order rate constant of metamitron degradation using combustion synthesized TiO2 was 1.5–2.5 times higher than that using commercial TiO2 at different initial concentrations of metamitron. The effect of another component, Rhodamine-B dye, on the degradation of metamitron was also probed in this study. The rate of degradation of both metamitron and Rhodamine B were high when the combined system was treated. The degradation by-products were tracked using liquid chromatograph/mass spectrometer, and a possible degradation pathway is proposed.

Fe–TiO 2 composite beads driven hybrid process of photocatalysis and photo-Fenton for the degradation of isoproturon

The concept of hybrid process of photo-Fenton and photocatalysis, particularly in the fixed mode, has been presented in this study for the degradation of the pesticide isoproturon with reduction at the time of treatment. For fixed-bed studies, spherical beads were prepared by combining definite proportions of clay, foundry sand, and fly ash, which were utilized as iron sources for titanium dioxide (TiO2) immobilization. The optimization of various parameters was performed by utilizing the Box–Behnken design model under response surface methodology. The process of degradation followed first-order kinetics under an optimized condition for the integrated degradation of isoproturon with a 700 mg·L-1 dose of H2O2, 42 spherical beads, and 190 mL of solution for a duration of 176 min at pH 3.7. Approximately 80.96% degradation of isoproturon was observed after inducing the optimized conditions. The integrated treatment was also carried out in a solar batch reactor under optimized conditions to expand its application to industries for treating bio-recalcitrant compounds. The mineralization of isoproturon was confirmed through the generation of nitrate, nitrite, and ammonical nitrogen with a definite chemical oxygen demand reduction. The recyclability of the catalyst was confirmed by recycling the spherical beads characterized by scanning electron microscopy–energy dispersive X-Ray analysis. For confirming the dual effect, that is, the presence of TiO2 along with Fe on the bead’s surface, various analyses including UV–diffuse reflectance spectroscopy, scanning electron microscopy–energy-dispersive spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy were carried out. A tentative pathway for isoproturon removal was also predicted based on intermediate analysis through gas chromatography–mass spectroscopy.

Highly efficient Imprinted Polymer Nanocomposites for photocatalytic desulfurization of real diesel fuel

The well-prepared imprinted nanocomposite polymer (MIP/AgPx) was used as a highly photo-active material in the oxidative desulfurization process. The synthesized nanocomposites were characterized using various analytical techniques including X-ray diffraction (XRD), UV diffuse reflectance spectroscopy (UV-DR), Fourier-transform infrared spectroscopy (FTIR), Photoluminescence spectroscopy (PL), and scanning electron microscope (SEM). The experimental parameters of the photo-desulfurization process, such as the source of radiations, the dosage of catalyst, reaction time, and addition of oxidizing agents such as hydrogen peroxide (H 2 O 2 )/acetic acid, were evaluated. The photo-degradation efficiency of dibenzothiophene (DBT, 450 ppm) was achieved ∼ 96% at room temperature in the presence of oxidizing agents with irradiation time 2h using xenon lamp (420 nm, 500 W). The removal efficiency enhanced to be 98% at the optimum conditions with high-quality diesel index: 96.17. The photocatalytic activity was attributed to the reduction of the recombination rate between electrons & holes and fast charge transfer. Furthermore, the MIP/AgP25 can be quickly recovered and reused by simple filtration for six times with a negligible decrease in the catalytic performance. • The imprinted polymer MIP/AgPx was used in the oxidative desulfurization process. • The catalytic photochemical process has highly proven desulfurization performance. • The treatment of real diesel leads to 96% degradation of organic sulfur compounds. • The prepared composite proven to be reused for 6 times with high activity and stability.

Facile fabrication of green nano pure CeO2 and Mn-decorated CeO2 with Cassia angustifolia seed extract in water refinement by optimal photodegradation kinetics of malachite green.

To eradicate the aquatic pollution caused by dyes, trendily the global researchers provide dedication to dye degradation using nanostructured photocatalyst. This research work is dedicated to explore an advanced, facile, bio-compact green fabricated nanostructure for water refinement. In this regard, plant-mediated syntheses of pure CeO2 and Mn-decorated CeO2 nano-powders have been inspected using seed extract of Cassia angustifolia. Investigations through UV-diffuse reflectance spectroscopy explored the significantly tuned band gap of Mn:CeO2. FT-IR spectroscopy shows the existing functional groups of high-potential phenolic compounds, proteins, and amino acids in Cassia angustifolia act as reducing and capping agents involved in the green fabricated nanostructured samples. X-ray diffraction pattern has been exposed to crystalline cubic fluorite morphology in a single phase and it leads to a regulated optimized amount of Mn on CeO2 nanostructure. The FESEM analysis predicts the morphology of CeO2 in spherical and Mn:CeO2 in flower-like structure. The HRTEM analysis has portrayed particle size of CeO2 is 11nm and tuned Mn:CeO2 nanostructure is 9nm. The HRTEM images revealed the average particle size in the range 10-12nm in CeO2 and 8-9nm in 5mol% Mn:CeO2 nanoparticles. It showed a decrease in average particle size with an increase in Mn concentration and the reduction in size may be due to the replacement of Ce(IV) with Mn(II) ions. The elemental composition in nanostructure was predicted using energy-dispersive X-ray analysis. The rapid photocatalytic degradation efficiency of malachite green was effectually performed and compared with the kinetics model of Mn:CeO2 and pure CeO2 nanostructures. From the augmented results, tuned Mn:CeO2 was found to act as the finest green fabricated photocatalyst in the amputation of lethal and carcinogenic dye.

Features of Lignin Destruction in Wood under the Action of Ozone

Samples of pine wood ozonated with different contents of water are studied via UV diffuse reflectance spectroscopy. It is shown that polyaromatic and stilbene structures, guaiacyl derivatives, and carbonyl- and carboxyl-containing aromatic structures of lignin are destroyed during ozonation of pine wood. The destruction of aromatic structures proceeds efficiently in wood with a moisture content of more than 60–65% in the 2–3 mmol/g range of ozone consumption. When the moisture content is below 40%, ozone treatment of pine wood at low ozone consumption allows us to obtain different modifications of oxygen-containing aromatic and polyaromatic structures on surfaces of lignocellulosic material (LCM). IR absorption spectra of dioxane lignin obtained from the initial and ozonated wood samples confirm the different direction of lignin transformations, depending on the content of moisture in the wood.

Investigation on structural, optical and electrochemical behavior of NiO/ZnMn2O4 ternary nanocomposites via two-step synthesis approach for supercapacitor application

The present investigation deals with the synthesis of nickel oxide (NiO)/zinc manganite (ZnMn2O4) nanocomposites (NCs) by a two-step approach. The powder X-ray diffraction (PXRD) pattern revealed the existence of face-centered cubic (FCC) phase of NiO and tetragonal rutile phase structure of ZnMn2O4 in NiO/ZnMn2O4 NCs. The optical properties of NiO/ZnMn2O4NCs have been investigated by the UV-diffuse reflectance Spectroscopy (UV-DRS) and photoluminescence (PL) spectral analysis. The surface morphology and elemental composition of NiO/ZnMn2O4NCs was investigated by field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectrum (EDX) analysis. The surface area and the nature of porosity of the samples were analyzed using Brunauer–Emmett–Teller (BET) method. The electrochemical properties were investigated from the cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) measurements. In 0.5 M potassium hydroxide (KOH) electrolyte solution, NiO/ZnMn2O4NCs exhibited higher specific capacitance of 886 F/g at a current density of 1Ag−1 with high cyclic stability over 1000 charge–discharging cycles. Thus, the result demonstrates that the prepared NiO/ZnMn2O4NCs is a promising electrode material for future energy-storage devices.