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Ni doped V2O5 nanorods were synthesized by simple sol–gel route. The effect of Ni doping has been studied through XRD, Micro-Raman, SEM and CV analysis. The XRD result shows that the synthesized samples were exhibits orthorhombic structured V2O5. SEM images illustrate the Ni particles are decorated on the V2O5 rod surfaces. From the Raman analysis, the prepared samples are observed in V-O vibrational modes without impurities. Both V2O5 and Ni:V2O5 electrodes are exhibits pseudocapacitance nature, which shows the superior specific capacitance values for 112 and 152 Fg−1 at 10 mVs−1, respectively.

In this paper, we report Tin Selenide (SnSe) nanoparticles preparation through co-precipitation method and characterised by UV–Vis spectroscopy, scanning electron microscopy, Fourier transforms inf...

Europium vanadate (EuVO4) nanorods were synthesized via the facile solvothermal route by using europium oxide as europium (Eu) source and ammonium metavanadate as vanadium (V) source. The synthesized EuVO4 nanorods were characterized by X-ray diffraction spectrum (XRD), Fourier transform spectroscopy (FTIR), micro-Raman spectroscopy, scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), ultraviolet (UV)–visible absorption spectrum, and photoluminescence (PL) to find the structural, optical, morphological, and magnetic and luminescence behaviors. Also, electrochemical analysis was performed to analyze the capacitive nature of the prepared EuVO4 electrodes by using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. XRD spectrum declares that the synthesized EuVO4 nanorods were highly crystalline in nature with tetragonal structure. FTIR and micro-Raman spectrum reveals the bonding nature of the prepared EuVO4 nanorods. SEM and HRTEM expose the rod-shaped morphology of the prepared EuVO4 nanorods. EDX spectrum justifies the purity of the prepared sample by showing the only presence of Eu, V, and O elements. UV–Vis spectrum shows the broad band from 260 to 280 nm which is due to VO43− absorption. PL spectrum of EuVO4 nanorods illustrate the electronic transitions that occur at 4f6, 5d1 → 4f7, which make an excellent photoluminescence emission in the region of blue (484 nm). From the CV and GCD studies, the maximum specific capacitance values of the EuVO4 nanorods were estimated as 106.9 F g−1 (5 mV s−1) and 146 F g−1 (1 A g−1) and the Columbic efficiency for 5 A g−1 and 6 A g−1 as 94.7% and 94.5%, respectively, which gives hope for the prepared EuVO4 nanorods that can act as perfect electrodes in supercapacitors.

In this study, pristine ZrO2 (600 °C) and Mg (0.02, 0.04, 0.06, 0.08 M)-doped ZrO2 nanoparticles were effectively synthesized at about 10 nm size and achieved complete degradation of methyl violet and methyl blue dyes under UV irradiation. The calcined products were analyzed by XRD, FTIR, UV-DRS, PL, FESEM-EDX, TEM-SAED pattern and XPS techniques. The tetragonal crystal structure of the pristine ZrO2 and Mg (0.02–0.08 M)-doped ZrO2 nanoparticles were affirmed by XRD analysis. The Mg (0.08 M)-doped ZrO2 nanoparticles were approximately in quasi-spherical morphology and high agglomeration was confirmed by FESEM and TEM results. The surface defects and oxygen vacancies were analyzed by PL spectroscopy. The Mg (0.08 M)-doped ZrO2 nanoparticles exhibited enlarged photocatalytic activity with 94% and 90% degradation of methyl violet and methyl blue dyes under UV irradiation.

Reduced graphene oxide (RGO) anchored vanadium pentoxide (V2O5) nanorods have been synthesized by using simple and cost efficacious sol–gel method. The prepared sample was analyzed by different physical and electrochemical techniques such as TG/DTA, XRD, XPS, FTIR, Micro-Raman, FESEM, HRTEM and cyclic voltammetry and galvanostatic charge/discharge. The electrochemical characterization shows that all the curves exhibit quasi-rectangular shape with redox peak, which indicates the pseudocapacitance nature of the V2O5 and RGO/V2O5 electrode materials. V2O5 electrode material exhibits the high specific capacitance (112 F/g) at low scan rate (10 mV/s) due to high surface area. The RGO/V2O5 electrode material exhibits two folds greater specific capacitance values (218.4 F/g at 10 mV/s) than pure V2O5 electrode material. This result clearly indicates the pseudocapacitance nature was enhanced by the RGO nanosheets. The GCD curve also reveals the RGO/V2O5 electrode has good charge/discharge time and superior specific capacitance than bare V2O5 electrode. These excellent electrochemical activities may credit due to RGO nanosheets, which induce large transfer of electrons and also provides high surface sites and short transport path length for the diffusion of electrolyte ions.

In this paper, tin Sulfide (SnS) nanoparticles are synthesized with three different solvents through hydrothermal method and characterized by using X-ray diffraction, scanning electron microscopy, UV-DRS spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectrum, supercapacitor, and photovoltaic performance. XRD patterns indicate that the prepared SnS nanoparticles exist in the orthorhombic phase. The SEM analysis clearly picturizes the morphological changes in the SnS nanoparticles synthesized through different solvents. The UV-DRS spectrum gives direct energy band gap which lies between 1.0 and 2.0 eV. The FT-IR spectrum explains various functional groups present in the SnS nanoparticles. The prepared SnS counter electrodes (CEs) showed good electrocatalytic activity in the redox reaction of the I−/I3−. The efficiency of tin sulfide prepared in ethanol (SnS-e), tin sulfide prepared in acetone (SnS-a), and tin sulfide prepared in methanol (SnS-m) counter electrodes (CEs) are 9.99%, 9.90%, and 9.86% in Dye-sensitized solar cells (DSSC) than that of platinum counter electrode which is 9.80%. The specific capacitance of 284 F/g is obtained for SnS-e electrode at a current density of 5 A/g and an energy density of 216 Wh/kg corresponding to power density value of 1.6 KWh/kg which proves SnS-e electrode possesses better capacitive performance than SnS-a and SnS-m electrodes, respectively.

Pure ZrO2 and Mn (0.02, 0.04, 0.06, 0.08 M) doped ZrO2 nanoparticles were successfully prepared by chemical precipitation method. The structural, optical, morphological and electronic properties were determined using XRD, UV-DRS, PL, FE-SEM, TEM and XPS techniques. The XRD pattern of pure and Mn doped ZrO2 shows the formation of t-tetragonal phase and shifting of tetragonal phase to monoclinic phase. The energy gap of pure and Mn doped ZrO2 nanoparticles were computed by UV-DRS spectroscopy. The energy gap value of pure and Mn doped ZrO2 nanoparticles decreased from 5.12 to 2.46 eV with increase of manganese concentration. X-ray Photoelectron spectroscopy (XPS) affirmed the presence of Zr4+ and Mn2+ ion in prepared nanoparticles. PL spectra of the pure and Mn doped ZrO2 nanoparticles exhibited oxygen vacancies. The photocatalytic actvity of Mn (0.08 M) doped ZrO2 nanoparticles was successfully sought on photo degradation of Methyl violet and Methylene blue under sunlight irradiation.

CdSe:Zn/CdS core–shell nanoparticles have been synthesized through the chemical precipitation method. The structural, optical and morphological properties of the synthesized core–shell nanoparticles were characterized by an X-ray diffraction, UV–vis absorption spectroscopy, photoluminescence spectroscopy and high-resolution transmission electron microscopy techniques. The X-ray diffraction analysis of the synthesized core–shell nanoparticles confirms the formation of cubic phase. The absorption and emission spectra of the synthesized core–shell nanoparticles show the red shift with respect to the CdS shell thickness on Zn-doped CdSe core. High-resolution transmission electron microscopy images display the synthesized core–shell nanoparticles were in spherical shape.

Undoped and Zn-doped CdSe quantum dots (QDs) were successfully synthesized by the chemical precipitation method. The structural, optical and morphological properties of the synthesized undoped and Zn-doped CdSe QDs were studied by X-ray diffraction (XRD), UV–visible absorption spectroscopy, photoluminescence (PL) spectroscopy, fluorescence lifetime spectroscopy, scanning electron microscopy (SEM), field emission transmission electron microscopy (FE-TEM) and FTIR. The synthesized undoped and Zn-doped CdSe QDs were in cubic crystalline phase, which was confirmed by the XRD technique. From the UV–visible absorption spectral analysis, the absorption wavelengths of both undoped and Zn-doped CdSe QDs show blue-shift with respect to their bulk counterpart as a result of quantum confinement effect. The highest luminescence intensity was observed for CdSe QDs doped with 4% Zn by PL studies. TEM analysis shows that the prepared QDs are spherical in shape.

In this paper Se NPs have been synthesised through precipitation technique by using different sorts of solvents such as sodium hydroxide, tin chloride, sodium borohydride, hydrochloric acid and citrus acid so as to consider its antibacterial activities. These Se NPs are characterised by experimental techniques such as UV-Vis spectrophotometer, SEM, TEM, FT-IR, XRD, EDX and antibacterial activities. Powder XRD analysis reveals the hexagonal phase (HCP) of Se NPs with average particle size of 27 nm. SEM and TEM reveal agglomerated spherical images with spherical shape and EDX spectra of the pure Se NPs show the peaks of pure selenium. Maximum absorption occurs in the range of 200–400 nm with an energy band gap of 3.58 eV. Presence of different functional groups liable for the production and stability of the Se NPs was confirmed by FT-IR spectrum. The antibacterial activity was achieved against two Gram-negative microorganisms (Escherichia coli, Salmonella typhi) and two Gram-positive microorganisms (Staphylococcus aureus, Streptococcus epidermidis).

Ni, Zn co-doped CdSe quantum dots (QDs) were synthesized by chemical precipitation method through aqueous route. The prepared QDs were characterized by X-ray diffraction (XRD) technique, UV–Vis absorption spectroscopy, photoluminescence (PL) spectroscopy and high resolution transmission electron microscopy (HRTEM). XRD technique results indicate that the prepared samples have a zinc blende cubic phase. From UV–Vis absorption spectroscopy technique, the prepared samples were blue shifted with respect to their bulk counter part due to quantum confinement effect. Among different doping ratios examined, a maximum PL emission intensity was observed for CdSe:Ni(1 %):Zn(1 %) QDs. HRTEM pictures show that the prepared QDs were in spherical shape.

This article reports the synthesis of undoped and Ni (1–5%) doped CdSe quantum dots (QDs) through chemical precipitation method. The structure and size of synthesized QDs were studied by X-ray diffraction pattern. The absorption wavelength of both samples were blue shifted with respect to the bulk CdSe phase due to quantum confinement effect. The enhanced photoluminescence was observed for Ni (2%) doped CdSe QDs. The morphology of the undoped and Ni (2%) doped CdSe QDs was studied using FE-TEM analysis.

The spectroscopicstudies have been carried out for Indian Portland cement hydrated with distilled and sea water in a water to cement ratio of 0.4. This study aims to analyze the effect of water on Portland cement. FTIR, DTA, XRD and EPR studies were used to characterize the hydration reaction of the cement pastes. Experimental results on setting time, compressive strength are also reported. The unreacted clinker phases and g-factors are calculated. The results indicate that sea water accelerates the cement hydration at early stage but retards in the latter stage of hydration.

The present works reports the effect of Flyash on the properties of Portland cement hydrated with ground water and seawater through magnetic susceptibility study. Cement pastes containing 0, 10, 20, 30% replacement of flyash with cement and in a Water cement ratio (W/C) ratio of 0.4 have been prepared. The magnetic susceptibility at different hydration ages has been determined by Faraday Curie balance method and this has been correlated to changes in setting time and compressive strength measurement. The observed result shows that, irrespective of water the magnetic suscepti- bility increases with increasing flyash percentage replacement level in cement.

The present work reports the effect of waste glass (WG) on the properties of Portland cement through Electron Para- magnetic Resonance (EPR) study. Cement pastes containing 0, 10, and 30% replacement of waste glass with cement and in a water to cement ratio of 0.4 have been prepared. The g factors of Fe(III) and Mn(II) impurities at different hydration ages have been calculated. The decreased gFe values and simultaneous increase in gMn values with increase in replacement % of WG are explained due to retardation of cement hydration.

The present works reports the hydration processes of Portland cement through Electron paramagnetic resonance study. Cement pastes in a Water to cement ratio (W/C) of 0.4 at different hydration time intervals have been prepared. The g-factor of Fe(III) and Mn(II) impurities at different hydration ages has been related to changes in setting time of cement. Both gFe and gMn values are reach a maximum values at final setting time of OPC paste.

The present research deals with strength, porosity and hydric behavior of metakaolin cement admixtured with different types of water. The hydration of ordinary Portland cement in the presence of 0%, 10%, 20% and 30% metakaolin treated with distilled, ground and sea water with the water to cement ratio of 0.4 was studied. The experimental results on setting time, strength, porosity and hydric parameters are reported. The results show that, metakaolin percentage increases in strength with a decrease in porosity. The observed results are discussed with SEM micrographs. Further, sea water accelerates the cement hydration at the early stages but retards it in the latter stages of hydration.

The role of metakaolin in the properties of Portland cement hydrated with ground water and sea water was described by magnetic susceptibility study. Cement pastes containing 0wt%, 10wt%, 20wt% and 30wt% replacement of metakaolin and in a water/cement (W/C) ratio of 0.4 were prepared. The susceptibility at different hydration periods was determined by Faraday Curie balance and it was related to the changes in setting time and compressive strength of admixtured cement. Compared with sea water-treated cement paste, the magnetic susceptibility of ground water-treated cement paste is higher in value. The observed result shows that, irrespective of water, the magnetic susceptibility increases with increasing metakaolin percentage replacement level in cement.

The present work reports the effect of metakaolin (MK) on the properties of Portland cement through electron paramagnetic resonance study. Cement pastes containing 0%, 10%, 20% and 30% replacements of MK with cement and a water to cement ratio of 0.4 have been prepared. The g factors of Fe(III) and Mn(II) impurities at different hydration ages have been related to changes in the setting time of cement. The increase in g Fe values and simultaneous decrease in g Mn values with an increase in the replacement percentage of MK are explained due to pozzolanic reaction.

Pastes containing High Alumina Cement (HAC) and Ordinary Portland Cement (OPC) were prepared using Ground Water (GW) and 5, 10, 15 and 20%SF. The setting time and compressive strength of these admixtured cement pastes were measured. The hydrated HAC blends were subjected to DTA/TG and DSC analysis. The recorded spectra were compared with the observed mechanical measurements of these blends. The hydration kinetics is well explained through these results. It is evidenced that 10%SF addition is optimum for this blend.

The dielectric constant (?') of Sulfate Resisting Portland Cement (SRPC) blended with 30% of fly ash by addition ismeasured using microwave bench at 9.54 GHz, for initial 30 hours of hydration. The heat of hydration for the sameblend using heat of solution calorimetry is also measured. It is observed that contrary to the usual trend of retarding offly ashes, it shows an accelerating trend with increasing strength as times passes. SEM micrographs and XRD patternsare also recorded and observed that C4Al2SO16 (C4A3S¯) is found to be responsible for the accelerating trend of the mix.The hydration process in the early period is studied and it is suggested that suitable retarder should be adopted for theeffective utilization.Cement chemistry notations: C=CaO, A=Al2O3, S¯=SO3, H=H2O, F=Fe2O3, S=SiO2

The paper aims to investigate hydration and pozzolanic reaction in Portland cement paste with different replacement percentages (0%, 10%, 20% and 30%) of metakaolin. The compressive strength of the metakaolin admixtured cement was measured at 1 day, 1 week and 4 weeks. The compressive strength developments of the metakaolin admixtured cement are compared with Portland cement. It is found that metakaolin contributes significantly to strength development as an accelerating admixture for Portland cement. The pozzolanic reactions and the reaction products were determined by DTA, XRD and SEM.