Abstract: A composite material comprising NiMoO4—CoMoO4 nanosheets can be an electrode in a hybrid supercapacitor. A hybrid supercapacitor having a cathode comprising the composite material exhibits a large operating window, high energy density and high cycling stability. The heterostructure material may be formed by a one-step chemical bath deposition process.

Abstract: The high-rate hybrid supercapacitor (HSC) has a positive electrode made from copper oxide (CuO)-cobalt oxide (CoO) core-shell nanocactus-like heterostructures produced on a nickel foam substrate, a negative electrode made by coating nickel foam with graphene ink, and a separator of cellulose paper. The heterostructures each have a core of CuO nanoflakes and a shell of CoO nanoneedles extending from the nanoflakes. The HSC achieves a specific capacity of 173.9 mA h g?1 at 1 A g?1 and long cycle life with 94% retention over 5000 cycles at 4 A g?1, and also exhibits a stable operating voltage window of 1.6 V, energy density of 56.5 W h kg?1, and cycling stability of 98.8% retention with coulombic efficiency of 98.7% over 4000 cycles.

Abstract: The quantum dot-sensitized solar cell (QDSSC) includes a photoelectrode, a counter electrode, and an electrolyte sandwiched between the photoelectrode and the counter electrode. The photoelectrode is formed from a titanium dioxide (TiO2) layer, a cadmium sulfide (CdS) quantum dot sensitizer layer, and a tin dioxide (SnO2) nanograss layer sandwiched between the titanium dioxide (TiO2) layer and the cadmium sulfide (CdS) quantum dot sensitizer layer.

Abstract: A quantum dot sensitized solar cell (QDSSC) includes a highly catalytic Ni-doped CuS thin film as a counter electrode (CE). The Ni-doped CuS CE can deliver outstanding electrocatalytic activity, conductivity, and low-charge transfer resistance at the CE/electrolyte interface. As a result, the QDSSC can achieve higher efficiency (?=4.36%) than a QDSSC with a bare CuS CE (3.24%).

Abstract: Hierarchical nanostructured cathode and anode are provided for an asymmetric supercapacitor, with the cathode including Co9S8—Ni3S2 nanoparticles anchored on CuMn2O4—NiMn2O4 nanosheet arrays and the anode including rhombus-like shaped MnFe2O4—ZnFe2O4 nanocrystals grown on a graphene-ink coated Ni foam. The asymmetric supercapacitor with the cathode and anode exhibits a large operating window, high energy density, and high cycling stability.

Abstract: The method of synthesizing magnetite/maghemite core/shell nanoparticles is a modified co-precipitation method for producing iron oxide (Fe3O4/?-Fe2O3) nanoparticles that allows for production of the Fe3O4/?-Fe2O3 core/shell nanoparticles with a desired shell thickness ranging between about 1 nm to 5 nm for biomedical and data storage applications. Aqueous solutions of ferric and ferrous salts are mixed at room temperature and pH of the mixture is raised to 10. The mixture is then heated at 80° C. for different lengths of time at atmospheric pressure to adjust particle size, and the precipitate is dried at 120° C. in vacuum. Oxidation in an oxygen atmosphere for different lengths of time is used to adjust the thickness of the ?-Fe2O3 shell.

Abstract: The method of synthesizing magnetite/maghemite core/shell nanoparticles is a modified co-precipitation method for producing iron oxide (Fe3O4/?-Fe2O3) nanoparticles that allows for production of the Fe3O4/?-Fe2O3 core/shell nanoparticles with a desired shell thickness ranging between about 1 nm to 5 nm for biomedical and data storage applications. Aqueous solutions of ferric and ferrous salts are mixed at room temperature and pH of the mixture is raised to 10. The mixture is then heated at 80° C. for different lengths of time at atmospheric pressure to adjust particle size, and the precipitate is dried at 120° C. in vacuum. Oxidation in an oxygen atmosphere for different lengths of time is used to adjust the thickness of the ?-Fe2O3 shell.