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Electrochemical supercapacitors could be thought of as a major energy storage instrument for electrical devices. Nano metal oxides supercapacitors as materials with high electro-activity are attracting supreme consideration due to the best electrochemical efficiency. In this project, synthesis of pure and gold doped PdO-reduced graphene oxide nanocomposites by sonochemical and deposition-precipitation process was performed. The characterization of synthesized un-doped and Au doped PdO-RGO composites were performed by using X-ray photoelectron and Raman spectroscopy, transmission electronic microscopy, and X-ray diffraction method. The characterization results demonstrated PdO particles are embedded into the interlayer of RGO sheets. The electrochemical supercapacitive efficiency of the nanosamples was evaluated by different electrochemical analysis. Au-doped PdO-RGO nanocomposite shows enhanced specific capacitance of 253.0 Fg− 1 at 5 mVs− 1 and its high excellent effect was collated with PdO-RGO. The high cyclic stability and specific capacitance of Au doped PdO-RGO demonstrates to the doping of gold and good dispersion of PdO particles on RGO.

TiO2 nanofibers were synthesized by hydrothermal method and characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM). The specific surface area of the nanofibers was determined using the Brunauer–Emmett–Teller (BET) method. The value of specific surface area was 67.89 m2 g− 1 for TiO2 nanofibers. The aim of this study was to evaluate the effectiveness of TiO2 nanofibers in removal of Diazepam from water solutions. The maximum adsorption capacity occurred in Diazepam concentration of 20 mg/l, contact times of 60 min, pH = 6 and adsorbent mass of 0.09 mg/L. The result of the Langmuir and Freundlich isotherm study show that of TiO2 nanofibers behave more similar to Langmuir isotherm model. The adsorption process was exothermic and TiO2 nanofibers follow the pseudo second order kinetic model and the other adsorbent follows the pseudo first order kinetic model. Since TiO2 nanofibers are available and affordable and according to this study have high capacity for removal of Diazepam. Finally, the catalytic ability of TiO2 nanofibers was investigated for catalytic ozonation of Diazepam. Results showed that TiO2 nanofibers have high efficiency in catalytic ozonation of Diazepam.

Heavy metals, such as vanadium, are some of the most toxic types of water contaminants. In this study, vanadium was removed using a new nanocomposite adsorbent called PdO-MWCNTs. The effects of pH and initial concentration of vanadium (V) on the removal efficiency of this metal by using PdO-MWCNTs were investigated in the first step of the study. Vanadium removal decreased as pH increased to 3–10. The removal efficiency then decreased. Response surface methodology and central composite design were applied to investigate experimental data. Initial concentration of V (mg/L), pH, and dosage of adsorbent (g/L) were the independent factors. Based on RSM, the removal effectiveness of vanadium was 95.47% at the optimum of initial concentration (60.0 mg/L), pH (3.0), and adsorbent dosage (1.0 g/L). Adsorption isotherm study shows the Langmuir isotherm could explain vanadium adsorption by PdO-MWCNTs better than the Freundlich isotherm. The adsorption equilibrium and kinetic data were well fitted and found to be in good agreement with the Langmuir isotherm and pseudo-second-order kinetic model.

A novel multi-walled carbon nanotubes–WO3–Pt nanocomposite (Pt-WO3-MWCNTs) was synthesized using a simple facile two-step precipitation method. Several analytical techniques such as X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, were used for the surface characterization of the synthesized nanocomposites and the specific surface area of the synthesized nanocomposites i.e. WO3-MWCNTs and Pt-WO3-MWCNTs using BET method was found to be 24.31 and 37.81 m2/g respectively. Effective parameters such as pH, reaction time, temperature, and initial concentrations which plays a significant role in adsorption phenomenon of typical hazardous pharmaceutical waste on Pt-WO3-MWCNTs was optimized using the batch adsorption experiments and the optimized values of pH, and contact time is 5, and 1 h respectively. It was observed that the warfarin uptake decreases from 141.2 mg/g to 121.1 mg/g as the solution pH increases from 5 to 9. Non-linear regression method was adopted to analyze the obtained equilibrium data in terms of Langmuir, Freundlich, and Temkin models. The Langmuir isotherm fitted the equilibrium data best among the four models, and the adsorption capacity increased with the temperature increased from 5 °C to 35 °C. Hence, Pt-WO3-MWCNTs could be used as an efficient adsorbent for adsorption of warfarin.

Molybdenum trioxide (MoO3) and molybdenum disulfide (MoS2) nanoparticles were synthesized using simple and facile techniques, i.e. hydrothermal and co-precipitation method, respectively. The synthesized nanoparticles were nicely characterized using various investigative techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) for analysing the structural, textural, topological and photocatalytic properties. The effective parameters, i.e. contact time, pH and rate of degradation, were well investigated and elucidated. From the optimized data, it is clear that the high quantity adsorption and degradation of morphine onto the MoO3 and MoS2 nanoparticles at 30 min, and the %age removal of morphine onto the developed adsorbents, i.e. MoO3 and MoS2, increases quickly with the increase in the adsorbent dose up to 20 mg/L, and is later on followed by the sluggish augmentation with an increase in the adsorbent dose up to 25 g/L. The maximum %age degradation of morphine using MoO3 and MoS2 was approximately 95% and 98%, respectively. Hence, synthesized MoO3 and MoS2 nanoparticles show strong photocatalytic efficiency with cooperation between visible or UV light and ultrasonic irradiation for the degradation reaction, whereas photolytic and sonophotocatalytic degradation processes were found to operate independently.

Un-doped and carbon-doped zirconium dioxide (ZrO 2 ) nanoparticles were synthesized through the simple sol–gel method. The synthesized doped and un-doped nanoparticles were later characterized using various analytical techniques such as X-ray diffraction analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy. The optical properties were evaluated using photoluminescence and UV–Vis diffuse reflectance spectroscopy. The optimum doping level of the atom dopant for enhanced PL properties was analyzed through optical study. It was found that band gap of the synthesized nanoparticles increases with increase in the carbon doping amount and the presence of peaks of Zr 4 p , Zr 3 d , Zr 3 p 3/2 , Zr 3 p 1/2 , and Zr 3 s at 28.5, 181.5, 333, 346.5, and 433.5 eV indicates the presence of ZrO 2 additionally the peak of O 1 s at 530.9 eV is ascribed to O − 2 in ZrO 2 . Two peaks overlap around 282.5 and 286.7 eV, which possibly originate from carbon in Zr–C and Zr–O–C bonds. The antibacterial property of the synthesized carbon doped and un-doped nanoparticles was well investigated and elucidated. Results obtained revealed that the carbon-doped ZrO 2 nanoparticles exhibit enhanced antibacterial activities in comparison to the un-doped ZrO 2 , which could be attributed to the significant carbon synergistic effect.

Normative batch adsorption studies of Cefotaxime, Cefradine and Cefazolin onto the developed CdS-MWCNT nanocomposites were well elucidated and investigated. The whole experimentation was carried out as a function of several influential parameters such as adsorbent dose, pH, contact time, and temperature. The developed adsorbent i.e. CdS-MWCNT nanocomposites were found to have high specific surface area and prodigious adsorption capacity. Several adsorption isotherm models such as Freundlich, Langmuir, Temkin and Scatchard were applied for the examination of equilibrium data, but Langmuir isotherm was found to be well fitted and in good agreement with the equilibrium data. One of the key finding is that the adsorption capacity increases on increasing pH and decreasing temperature. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were calculated, the analysis showed negative values of ΔG, which reveals the spontaneous nature, negative values of ΔH reveals the exothermic nature as well as physical nature of adsorption, additionally negative values of ΔS reveals the decreased disturbance interface of Cefotaxime, Cefradine and Cefazolin removal using CdS-MWCNT nanocomposites.

To improve the performance of NiO nanoparticles under source light, a nitrogen and boron co-doped nano powder photocatalyst was collected. The UV–Vis diffusive reflectance spectroscopy (DRS) and photoluminescence (PL) spectroscopy were used to measure photoabsorbance. The morphology of NiO nanophotocatalyst was characterized using Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), and X-ray diffraction (XRD). The particle size was in correlation with the calcination temperature. It is found that the average crystallite size and specific surface area of the three co-doped NiO catalysts are near 9.57–10.21 nm, and 132.7–151.9 m2/g, respectively. Degradation of 1-chloro-4-nitrobenzene under UV and visible light illumination was applied to appraise the photocatalytic efficiency. The results indicated that the co-doping of nitrogen and boron performance is a major designation in the band gap decrease, which led to the enhancement of the activity of photocatalytic reaction. The binding energies of O 1s, Ni 2p1/2, Ni 2p3/2, N 1s and B 1s ready a justly complete image of the synthesis sample. The peak of Ni 2p3/2 that emerges at 855.6 eV indicated the detection for NiO. The peak of O 1s at 530.9 eV is ascribed to the O2 − in the NiO. The particles exhibited excellent antimicrobial property.

We report the preparation of the efficient photocatalyst Bi2O3, and FeS2-Bi2O3 nanocomposites. Nanomaterials prepared with sonochemical assisted hydrothermal methods. The morphology sensitization and optical changes of the nanocomposites were studied using dynamic light scattering and UV–vis spectroscopy analysis, X-ray photoelectron and diffraction analysis and Scanning Electron Microscopy. The crystallite size and band gap values of Bi2O3, FeS2-Bi2O3-0, FeS2-Bi2O3-1 and FeS2-Bi2O3-2 have obtained from XRD and UV–vis DRS analysis and found 50.12, 59.60, 61.42 and 63.44 nm and 2.85, 2.67, 2.56 and 2.50 eV, respectively. Photocatalytic degradation of Phenytoin as drug pollution has been investigated under UV light irradiation. The FeS2-Bi2O3–2 showed higher efficiency in the degradation of Phenytoin with 97.5% degradation efficiency after 50 min under UV light illumination. The optimum catalytic parameters such as time and pH were discussed. The efficacy of degradation of Phenytoin increased as time raised. The optimal pH was around 5 where the reaction rate decreases above and under this pH value. The other objective of this study is the investigation of cytotoxicity properties of FeS2-Bi2O3 nanocomposites against HeLa cell line with MTT assay method. The synthesized nanomaterials were tested for their antibacterial properties against pathogenic microorganisms Mycobacterium tuberculosis and Salmonella. The antimicrobial property FeS2-Bi2O3-2 was observed with a maximum of zone inhibition.