The development of cost-effective metal molybdates with enhanced energy storage capabilities has garnered significant attention as promising redox-active electrodes for asymmetric supercapacitors (ASCs). In this work, we synthesized binder-free copper molybdate (CMO) nanostructures on nickel foam using a simple hydrothermal process and thoroughly investigated their structural and electrochemical properties. The resulting CMO nanostructures exhibited a hybrid nanosheet–nanoplate morphology with a layered structure, providing an increased electroactive surface area. The structural integrity and elemental composition were confirmed using X-ray diffraction, X-ray photoelectron and X-ray (EDX) spectroscopy, showing a homogeneous distribution of copper, molybdenum, and oxygen elements. Electrochemical analysis showed that the hydrated CMO (CMO_BH) electrode provides higher specific capacitance and redox behavior than the thermally treated CMO (CMO_AH) electrode. The higher performance is attributed to the superior conductivity of CMO_BH and the presence of hydroxyl groups, which enhance redox-type charge storage. Moreover, the ASC device fabricated using the hydrated CMO_BH and activated carbon electrodes achieved a high operating voltage of 1.6 V with a maximum specific capacitance of 142.1 F g⁻¹ at 1 A g⁻¹, an energy density of 48.6 W h kg⁻¹ and a power density of 12.5 kW kg⁻¹, respectively. Additionally, the device demonstrated excellent cycling stability, retaining 89.1% of its capacitance after 10 000 cycles. The ASCs also successfully powered light-emitting diodes, emphasizing their potential for practical energy storage applications.

In the current work, aluminum dross from the aluminum industry and fired-clay brick waste (Homra) were combined with alkaline activators (Na₂SiO₃/NaOH) with varying molarities of NaOH to create insulating geopolymer bricks. An alkaline activator with an (S/L) ratio of 3/1 was combined with Homra to replace it partly. The mixture was then molded into 50 × 50 × 50 mm³ stainless steel molds. Water absorption, compressive strength, bulk density, and apparent porosity of the produced geopolymer were measured at various curing durations and NaOH molarities. The findings showed that adding more aluminum dross waste replacement leads to a decrease in bulk density and compressive strength and an increase in the creation of pores that improve the produced bricks’ ability to insulate against heat. Using 8 M of NaOH after 28 days, the findings revealed that 3% aluminum dross waste replacement has a compressive strength of about 8.6 MPa, water absorption of 14.6%, bulk density of 1.307 g/cm³, and thermal conductivity of 0.32 W/m·K. The Egyptian standard, ASTM C62, satisfies these outcomes. Using DesignBuilder energy simulation software version 6.1.06, the constructed insulating brick under ideal circumstances was utilized to calculate its contribution performance in energy consumption. The annual energy consumption was reduced by about 21% compared to traditional hollow cement bricks.