Photoelectrochemical cells for the oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid and/or 2,5-diformylfuran are provided. Also provided are methods of using the cells to carry out the electrochemical and photoelectrochemical oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid and/or 2,5-diformylfuran.

The invention concerns a solution of tungstate ions W.sup.6+ (VI) comprising as solvent at least one optionally partly etherified polyalcohol, a preparation method and uses thereof. The invention further concerns a layer comprising at least one tungsten oxide WO.sub.z comprising one or more polyoxotungstate complexes, methods for preparing the same and uses thereof, and in particular a photovoltaic device comprising said layer of material.

The present invention discloses an isodiketopyrrolopyrrole dye and use thereof. A series of pure organic dye based on isodiketopyrrolopyrrole are synthesized in the present invention, using 4,4′-dihexyloxytriphenylamine as an electron donor, isodiketopyrrolopyrrole as a π-bridge, and cyanoacetic acid as an electron acceptor and an anchoring group, and with a alkyl chain introduced on an isodiketopyrrolopyrrole group. The types of dyes have a relatively good light-harvesting performance as well as a relatively large steric hindrance, and they are not easy to gather while being absorbed on a semiconducting film. The pure organic dye with isodiketopyrrolopyrrole as an electronic π-bridge, which is used in a dye-sensitized solar cell, has a good ability of inhibiting the recombination of electrons, and the dye-sensitized solar cells have a high photoelectric conversion efficiency.

Described herein is an ink solution, comprising a composition of formula (I): ABX.sub.3(I), wherein A comprises at least one cation selected from the group consisting of methylammonium, tetramethylammonium, formamidinium, cesium, rubidium, potassium, sodium, butylammonium, phenethylammonium, phenylammonium, and guanidinium; B comprises at least one divalent metal; and X is at least one halide; and a mixed solvent system comprising two or more solvents selected from the group consisting of dimethyl sulfoxide, dimethylformamide, γ-butyrolactone, 2-methoxyethanol, and acetonitrile. Methods for producing poly-crystalline perovskite films using the ink solutions described herein and the use of the films in photovoltaic and photoactive applications are additionally described.

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 (TiO.sub.2) layer, a cadmium sulfide (CdS) quantum dot sensitizer layer, and a tin dioxide (SnO.sub.2) nanograss layer sandwiched between the titanium dioxide (TiO.sub.2) layer and the cadmium sulfide (CdS) quantum dot sensitizer layer.

The present invention provides a solid-liquid electrolyte in the form of a gel which comprises an organic carbonate-based solvent, precipitated silica, at least one ionically conducting salt and optionally additives. The invention also relates to batteries containing said solid-liquid electrolyte. The solid-liquid electrolyte according to the present invention can improve the electrochemical properties of batteries and prevent electrolyte leakage thus reducing the risk of corrosion of the batteries.

The present invention provides a hybrid ferroelectric discotic liquid crystal solar cell by incorporating an electrolyte composition for improving power conversion efficiency of the solar cell. The hybrid ferroelectric (FE) discotic liquid crystal solar cell comprises a first layer of n-type inorganic semiconductor deposited on conductive fluorine doped tin oxide (FTO) glass plate 101, a second thin layer of light absorbing inorganic sensitizer 103; wherein the inorganic sensitizer strained titania FTO glass-plate acts as a photo anode, a third layer of ferroelectric discotic liquid crystal electrolyte 104 applied between the photo anode and a photo cathode and a fourth layer of reflective platinum deposited FTO glass-plate 105 configured to act as the photo cathode. The ferroelectric discotic liquid crystal electrolyte composition comprises of an achiral HAT6 discotic molecule (2,3,6,7,10,11-Hexakis-hexyloxy triphenylene) and at least two additives, wherein the additives includes tertiary butyl pyridine (t-bPy) and lithium bis(trifluoromethylsulphonyl)imide Li[CF3SO2]2N.

The nitrogen battery of the present disclosure includes a positive electrode that uses nitrogen as a positive electrode active material, a negative electrode, and an ion conducting medium that contains a silane compound and conducts alkali metal ions.

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%).

An electrolytic solution comprising N-(fluorosulfonyl)-N-(fluoroalkylsulfonyl)imide or di(fluorosulfonyl)imide, from which a residual solvent that affects the properties of the electrolyte solution material is reduced, is provided. A method for producing an electrolyte solution material containing fluorosulfonyl imide salt represented by the following general formula (1) and an electrolyte solution preparation solvent comprises decompressing and/or heating a solution containing the fluorosulfonyl imide salt and the electrolyte solution preparation solvent to volatilize a production solvent for the fluorosulfonyl imide salt.

##STR00001##

In general formula (1), R.sub.1 represents a fluorine atom or a fluorinated alkyl group having 1 to 6 carbon atoms, R.sub.2 represents an alkali metal ion.