A method for producing a tetrahydroborate is disclosed. The method includes a plasma treatment step of exposing a borate to a hydrogen plasma. The method also includes that the plasma treatment is performed using hydrogen plasma generated by microwave or RF excitation, and the plasma treatment is performed while heating the borate at a temperature between 40° C. and 300° C.

A reducing material including a two-dimensional hydrogen boride-containing sheet having a two-dimensional network composed of (BH).sub.n (n≥4).

A composite including a two-dimensional hydrogen boride-containing sheet having a two-dimensional network composed of (BH).sub.n (n≥4) and a metal nanoparticle.

A reduction method including: a step of dispersing the reducing material according to any one of Claims 1 to 5 in an organic solvent to prepare a dispersion liquid containing the reducing material; and a step of reducing a metal ion having a redox potential which is given as a standard electrode potential of −0.26 V/SHE or higher by mixing the dispersion liquid with the metal ion.

The present disclosure relates to a method for producing a tetrahydroborate, the method including a plasma treatment step of exposing a borate to a hydrogen plasma.

A quantum dot device, a method of manufacturing the same, a thin film having a multilayered structure, and an electronic device including the same. The quantum dot device includes a first electrode and a second electrode, a quantum dot layer disposed between the first electrode and the second electrode, and a hole transport layer disposed between the quantum dot layer and the first electrode, wherein the hole transport layer includes a first hole transport layer including a three-dimensional structure perovskite thin film and a second hole transport layer including a two-dimensional structure perovskite thin film.

A method for obtaining solid-state metal borohydrides without toxic precursors and expensive solvents includes dry mixing of metal hydrides and metal polyhydro-closo-borate starting materials. High pressure and heating is also used in the method. These materials can be used for hydrogen storage, general reducing agents, organic synthesis, wastewater treatment, and paper pulp bleaching.

Heat ray shielding fine particles contain calcium lanthanum boride fine particles represented by a general formula Ca.sub.xLa.sub.1-xB.sub.m, a shape of each fine particle of the calcium lanthanum boride fine particles satisfies at least one of the following: 1) when scattering intensity of the calcium lanthanum boride fine particles diluted and dispersed in a solvent is measured using small-angle X-ray scattering, value Ve of a slope of a straight line is −3.8≤Ve≤−1.5, 2) the particle shape is a flat cylindrical shape, or a flat spheroidal (wherein a length of a long axis is d and a length of a short axis is h) shape, with a value of aspect ratio d/h being 1.5≤d/h≤20.

A two-dimensional hydrogen boride-containing sheet of the present invention has a two-dimensional network that consists of (HB).sub.n (n4).

Heat ray shielding fine particles contain calcium lanthanum boride fine particles represented by a general formula Ca.sub.xLa.sub.1-xB.sub.m, a shape of each fine particle of the calcium lanthanum boride fine particles satisfies at least one of the following: 1) when scattering intensity of the calcium lanthanum boride fine particles diluted and dispersed in a solvent is measured using small-angle X-ray scattering, value Ve of a slope of a straight line is 3.8Ve1.5, 2) the particle shape is a flat cylindrical shape, or a flat spheroidal (wherein a length of a long axis is d and a length of a short axis is h) shape, with a value of aspect ratio d/h being 1.5d/h20.

One aspect of this invention relates to synthesis of borophane polymorphs by hydrogenating borophene with atomic hydrogen in ultrahigh vacuum, including growing borophene on a substrate in an ultrahigh vacuum chamber; and performing hydrogenation of the borophene in situ to obtain borophane having a diverse set of borophane polymorphs. The borophane polymorphs are metallic with modified local work functions that can be reversibly returned to pristine borophene via thermal desorption of hydrogen. Hydrogenation also provides chemical passivation such that the borophane polymorphs have negligible oxidation for multiple days following ambient exposure.

A two-dimensional hydrogen boride-containing sheet of the present invention has a two-dimensional network that consists of (HB).sub.n (n4).