Provided is a novel polyoxometalate and a method for producing the polyoxometalate. The polyoxometalate is represented by the compositional formula: M.sub.xO.sub.y in which M is tungsten, molybdenum or vanadium; 4x1000; and 2.5y/x7.

Provided is a novel polyoxometalate and a method for producing the polyoxometalate. The polyoxometalate is represented by the compositional formula: M.sub.xO.sub.y in which M is tungsten, molybdenum or vanadium; 4x1000; and 2.5y/x7.

Disclosed is a process for the selective removal of copper compounds, and other impurities with respect to molybdenum and rhenium, from concentrates of molybdenite (MoS.sub.2) with a copper content that is higher than 0.5% in dry weight.

Disclosed is a process for the selective removal of copper compounds, and other impurities with respect to molybdenum and rhenium, from concentrates of molybdenite (MoS.sub.2) with a copper content that is higher than 0.5% in dry weight.

Methods are provided for growing a thin film of a nanoscale material. Thin films of nanoscale materials are also provided. The films can be grown with microscale patterning. The method can include vacuum filtration of a solution containing the nanostructured material through a porous substrate. The porous substrate can have a pore size that is comparable to the size of the nanoscale material. By patterning the pores on the surface of the substrate, a film can be grown having the pattern on a surface of the thin film, including on the top surface opposite the substrate. The nanoscale material can be graphene, graphene oxide, reduced graphene oxide, molybdenum disulfide, hexagonal membrane boron nitride, tungsten diselenide, molybdenum trioxide, or clays such as montmorillonite or lapnotie. The porous strate can be a porous organic or inorganic membrane, a silicon stencil membrane, or similar membrane having pore sizes on the order of microns.

Polymeric photovoltaic cell (or solar cell) with an inverted structure comprising: an anode; a first anode buffer layer; an active layer comprising at least one photoactive organic polymer as the electron donor and at least one organic electron acceptor compound; a cathode buffer layer; a cathode; wherein between said first anode buffer layer and said active layer a second anode buffer layer is placed comprising a hole transporting material, said hole transporting material being obtained through a process comprising: reacting at least one heteropoly acid containing at least one transition metal belonging to group 5 or 6 of the Periodic Table of the Elements; with at least an equivalent amount of a salt or a complex of a transition metal belonging to group 5 or 6 of the Periodic Table of the Elements with an organic anion, or with an organic ligand; in the presence of at least one organic solvent selected from alcohols, ketones, esters, preferably alcohols. Said polymer photovoltaic cell (or solar cell) with an inverted structure displays high photoelectric conversion efficiency values (), i.e. a photoelectric conversion efficiency () greater than or equal to 4.5%, and good open circuit voltage (Voc), short-circuit current density (Jsc) and fill factor (FF) values. Furthermore, said polymer photovoltaic cell (or solar cell) with an inverted structure is able to maintain said values over time, in particular, in terms of photoelectric conversion efficiency ().

Polymeric photovoltaic cell (or solar cell) with an inverted structure comprising: an anode; a first anode buffer layer; an active layer comprising at least one photoactive organic polymer as the electron donor and at least one organic electron acceptor compound; a cathode buffer layer; a cathode; wherein between said first anode buffer layer and said active layer a second anode buffer layer is placed comprising a hole transporting material, said hole transporting material being obtained through a process comprising: reacting at least one heteropoly acid containing at least one transition metal belonging to group 5 or 6 of the Periodic Table of the Elements; with at least an equivalent amount of a salt or a complex of a transition metal belonging to group 5 or 6 of the Periodic Table of the Elements with an organic anion, or with an organic ligand; in the presence of at least one organic solvent selected from alcohols, ketones, esters, preferably alcohols. Said polymer photovoltaic cell (or solar cell) with an inverted structure displays high photoelectric conversion efficiency values (), i.e. a photoelectric conversion efficiency () greater than or equal to 4.5%, and good open circuit voltage (Voc), short-circuit current density (Jsc) and fill factor (FF) values. Furthermore, said polymer photovoltaic cell (or solar cell) with an inverted structure is able to maintain said values over time, in particular, in terms of photoelectric conversion efficiency ().

A spinel compound oxide particle includes metallic atoms, aluminum atoms, oxygen atoms, and molybdenum atoms, wherein the metallic atoms are selected from the group consisting of zinc atoms, cobalt atoms, and strontium atoms, and a crystallite size in a [111] plane is 100 nm or more. Included are a step (1) of firing a first mixture including a molybdenum compound and a metallic-atom-containing compound or a first mixture including a molybdenum compound, a metallic-atom-containing compound, and an aluminum compound to prepare an intermediate; and a step (2) of firing, at a temperature higher than a temperature selected in the step (1), a second mixture including the intermediate or a second mixture including the intermediate and an aluminum compound.

A spinel compound oxide particle includes metallic atoms, aluminum atoms, oxygen atoms, and molybdenum atoms, wherein the metallic atoms are selected from the group consisting of zinc atoms, cobalt atoms, and strontium atoms, and a crystallite size in a [111] plane is 100 nm or more. Included are a step (1) of firing a first mixture including a molybdenum compound and a metallic-atom-containing compound or a first mixture including a molybdenum compound, a metallic-atom-containing compound, and an aluminum compound to prepare an intermediate; and a step (2) of firing, at a temperature higher than a temperature selected in the step (1), a second mixture including the intermediate or a second mixture including the intermediate and an aluminum compound.

This invention describes a new method for reducing the bandgap of titanium dioxide by forming solid solutions with other dioxides that a) have either rutile or anatase crystal structure, b) exhibit either metallic or semiconducting characteristics and c) maintain stable 4+ valence during high temperature processing as well as during cooling to room temperature.