Copper oxide (CuO) and cerium oxide (CeO2) of various concentrations have been prepared through an ultrasonically assisted dispersion of CuO and CeO2 nanoparticles (NPs) in which water and nanofluids (NFs) were formulated. The morphological properties of the CuO and CeO2 NPs are reported. Few of the physicochemical properties that can influence the photocatalytic activities of the NFs are evaluated, such as viscosity, activation energy, density, thermal conductivity, electrical conductivity, alternating current (AC) conductivity, pH, stability, refractive index and optical band gap of the CuO and CeO2 NFs. Viscosity studies have been made at four different temperatures (303 K, 308 K, 313 K and 318 K) and the activation energy is calculated and compared between the CuO and CeO2 NFs. The thermal conductivity of the two NFs is calculated and compared. Electrical conductivity is measured for CuO and CeO2 NFs using an impedance analyzer at different frequencies at 303 K. The dielectric constant and AC conductivity were studied. The electrical conductivity and pH of the prepared NFs are measured and the results are compared. The stability of the NFs is determined from Zeta potential values obtained from dynamic light scattering measurements. UV-Visible diffuse reflectance measurements were used to deduce the optical bandgap of the respective metal oxide NPs in the NFs. The photocatalytic efficiencies of the CuO NFs and CeO2 NFs were evaluated using methylene blue (MB) as the model dye. The rate constant for the photodegradation of MB was higher for CuO NF as compared CeO2 NF and also higher than simple NPs-based photocatalysts. A plausible explanation for the role of NFs over the simple NPs-based photocatalytic solution is presented.

<p>The conversion of biomass into valuable carbon composites as an efficient non-precious energy storage electrode material have elicited extensive research interest. As synthesized partially graphitized iron oxide-carbon composite material (Fe₃O₄/Fe₃C@C) shows an excellent property as an electrode material for supercapacitor. X-ray diffraction, High resolution transmission electron microscopy, X-ray photo-electron spectroscopy and Brunauer-Emmett-Teller analysis is used to study the structural, compositional and surface areal properties. The electrode material shows a specific surface area of 827.4 m²/g. Due to the synergistic effect of graphitic layers with iron oxide/carbide, Fe₃O₄/Fe₃C@C hybrid electrode materials display high-performance for supercapacitor with excellent capacity of 878 F/g at a current density of 5A/g (3-electrode) and 211.6 F/g at a current density of 0.4A/g (2-electrode) in 6M KOH electrolyte with good cyclic stability.</p>

<div><p>Here, we report a highly efficient adsorbent obtained from the carbonization of metallized bagasse. The material is characterized using FESEM, HRTEM, PXRD, zeta-potential and VSM techniques. The material shows an impressive adsorbent property for anionic dyes, pharmaceutical (paracetamol) along with commercially used ‘hair dye’. Further, pH triggered adsorption of Methylene orange (MO), Congo red (CR), Amido black (AB), and paracetamol were studied and results show an impressive adsorption capacity of 1102.9, 1253.9, 877.2, 227.8 mg/g respectively. It is seen that under experimental conditions, adsorbent shows ultrafast adsorption kinetics where ~96% AB dye gets adsorbed in just 5 min, 93% of CR adsorption in 5 min and ~89% of MO adsorption in 5 min. Also, we could observe fast adsorption rate for commercially used ‘hair dye’ and paracetamol drug. Interestingly, in just 5 min, 95% of hair dye adsorption is seen and ~84% drug removal with maximum adsorption capacity of , recyclability of the adsorbent demonstrates the practical benefits of the material for waste water remediation.</p></div>

Copper oxide nanoparticles are used in the synthesis of CuO nanofluids for increasing the thermal conductivity of nanofluids. The method of preparation of nanofluids in stable form is of much significant in the field of nanofluid and its application. In this present work, CuO nanoparticles (particle size: 40 nm) are dispersed in double distilled water and nanofluids are prepared at ten different concentration (0.2%-2.0%) in steps of 0.2 at room temperature. Viscosity studies are carried out at different temperatures (303K, 308K, 313K & 318K) for the prepared nanofluids. From the experimental values, the activation energy is calculated and ultrasonic velocity, density, refractive index and thermal conductivity studies are performed at room temperature. Various molecular interaction parameters are determined to analyze the nature of molecular interaction in the sample taken for study.