The incorporation of metal oxide nanoparticles into magnesium oxide (MgO) powder enhances its supercapacitor performance. This study investigates the influence of cooper oxide nanoparticles (CuO-NPs) incorporated into magnesium oxide (MgO) powder on the electrochemical performance of supercapacitors.  Magnesium oxide (MgO), Copper Oxide nanoparticles (CuO-NPs), and their composite (MgO/CuO) were synthesized and evaluated under both three- and two-electrode configurations. Structural, morphological, and electrochemical characterizations were performed to assess the effect of CuO addition. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the successful integration of CuO into the MgO matrix, accompanied by notable changes in crystallinity and particle morphology. Electrochemical performance was evaluated using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). The MgO/CuO composite demonstrated a markedly enhanced specific capacitance of 444.4 F/g at 2 A/g in a three-electrode system, significantly higher than individual MgO and CuO. The composite retained 96.8% capacitance after 5000 GCD cycles, showing excellent cyclic stability. EIS results revealed low series resistance, fast ion diffusion, and improved charge-transfer kinetics.  The enhanced performance is attributed to the synergistic interaction between MgO and CuO, which improves surface activity, electron transport, and structural stability, thereby establishing MgO/CuO as a promising, cost-effective, and environmentally benign electrode material for next-generation high-performance supercapacitors.

Passive solar-thermal systems depend on efficient heat transfer to keep absorber temperatures low. Nanofluid working media and microstructured copper interfaces can intensify boiling and rewetting using passive modifications. Integrated, stability-screened comparisons that combine nanofluids with fabricated microstructures under unified boundary conditions remain limited. This study quantifies the coupled influence of nanofluid formulation and copper surface topology on passive phase-change devices. Graphene, CuO, Al₂O₃, and TiO₂ nanofluids (0.05–0.30 wt%) were prepared and characterized for dispersion size, zeta potential, UV–Vis retention, viscosity, and thermal conductivity, and were tested in circular and flat-plate wicked heat pipes and a wickless thermosyphon with plain, hemispherical, and micropillar evaporators from 20–100 W at 0°–90° with triplicate repeats (k=2). Micropillar evaporators exhibit low resistance; the maximum reduction was 48% compared with plain copper, indicating enhanced capillary replenishment and wetted area. Graphene provides the strongest fluid effect; at 100 W on micropillars in the circular device, the thermal resistance fell from 0.210 to 0.168 °C/W, supporting coupled conductivity and interfacial conditioning. These quantified gains support absorber-interface redesign for higher energy efficiency and reduced orientation sensitivity. Future work targets long-cycle durability, fouling, and outdoor exposure of nanomaterial suspensions.

This review article is concerned with the environmentally benign manufacturing of nanoparticles using microorganisms, particularly fungi. To create nanoparticles, scientists and researchers have Used a variety of physical and chemical processes and procedures. However, these types of nanoparticles are not environmentally friendly and frequently allow for the release of hazardous substances, which could have a negative impact on both humans and the environment. As a result, it is crucial to develop affordable and eco-friendly nanoparticle synthesis techniques and adopt green syntheses by utilizing natural microorganisms like bacteria, fungi, algae, etc.  Fungi are the main focus for shaping these materials into nanoparticles since they can help cut processing time and manufacture nanoparticles in the proper size and form. They are the favored biological materials as the synthesized nanoparticles are non-toxic, thus energy efficiency is improved along with reduced environmental pollution. This is also the main justification for using fungal microorganisms in the synthesis of nanoparticles to produce ideal and non-toxic materials, which can assist in lessening the effects on the environment, improving energy efficiency, and reducing environmental pollution. The biological mechanism by which fungi synthesize iron nanoparticles, the development of diverse forms of iron nanoparticles by fungi, and the use of novel nanoparticles in the currently emerging industry are the main focus of this review.