The present disclosure generally relates to compositions comprising substrate-free 2D tellurene crystals, and the method of making and using the substrate-free 2D tellurene crystals. The 2D tellurene crystals of the present disclosure are characterized by an X-ray diffraction pattern (CuKα radiation, λ=1.54056 A) comprising a peak at 23.79 (2θ±0.1°) and optionally one or more peaks selected from the group consisting of 41.26, 47.79, 50.41, and 64.43 (2θ±0.1°).

The present disclosure generally relates to compositions comprising substrate-free 2D tellurene crystals, and the method of making and using the substrate-free 2D tellurene crystals. The 2D tellurene crystals of the present disclosure are characterized by an X-ray diffraction pattern (CuKα radiation, λ=1.54056 A) comprising a peak at 23.79 (2θ±0.1°) and optionally one or more peaks selected from the group consisting of 41.26, 47.79, 50.41, and 64.43 (2θ±0.1°).

A method for efficiently removal of oxidised selenium from liquid, such as FGD wastewater. The method involves adding a non-iron-based reducing agent (e.g. sodium dithionite) and preferably Fe(II) ions to the liquid at a pH of above 7.5 or 8 and precipitating elemental selenium from the liquid.

A method for efficiently removal of oxidised selenium from liquid, such as FGD wastewater. The method involves adding a non-iron-based reducing agent (e.g. sodium dithionite) and preferably Fe(II) ions to the liquid at a pH of above 7.5 or 8 and precipitating elemental selenium from the liquid.

A method for efficiently removal of oxidised selenium from liquid, such as FGD wastewater. The method involves adding a non-iron-based reducing agent (e.g. sodium dithionite) and preferably Fe(II) ions to the liquid at a pH of above 7.5 or 8 and precipitating elemental selenium from the liquid.

The invention relates to elemental selenium nanoparticles, especially a product containing selenium nanoparticules, that can be produced from at least one organic compound and at least one selenium source, with a step of drying by atomisation. The invention also relates to a method for producing such a product and to a method for enriching, with elemental selenium nanoparticles, a product which already comprises elemental selenium nanoparticles.

The invention relates to elemental selenium nanoparticles, especially a product containing selenium nanoparticules, that can be produced from at least one organic compound and at least one selenium source, with a step of drying by atomisation. The invention also relates to a method for producing such a product and to a method for enriching, with elemental selenium nanoparticles, a product which already comprises elemental selenium nanoparticles.

An electrically conductive thin film including a compound represented by Chemical Formula 1 and having a layered crystal structure:
A.sub.xM.sub.yCh.sub.z  Chemical Formula 1 wherein A is V, Nb, or Ta, M is Ni, Co, Fe, Pd, Pt, Ir, Rh, Si, or Ge, Ch is S, Se, or Te, x is a number from 1 to 3, y is a number from 1 to 3, and z is a number from 2 to 14.

An electrically conductive thin film including a compound represented by Chemical Formula 1 and having a layered crystal structure:
A.sub.xM.sub.yCh.sub.z  Chemical Formula 1 wherein A is V, Nb, or Ta, M is Ni, Co, Fe, Pd, Pt, Ir, Rh, Si, or Ge, Ch is S, Se, or Te, x is a number from 1 to 3, y is a number from 1 to 3, and z is a number from 2 to 14.

Provided is a method of making colloidal selenium nanoparticles. The method includes the steps as follows: Step (A): providing a reducing agent and an aqueous solution containing a selenium precursor; Step (B): mixing the aqueous solution containing the selenium precursor and the reducing agent to form a mixture solution in a reaction vessel and heating the mixture solution to undergo a reduction reaction and produce a composition containing selenium nanoparticles, residues and a gas, and guiding the gas out of the reaction vessel, wherein an amount of the residues is less than 20% by volume of the mixture solution; and Step (C): dispersing the selenium nanoparticles with a medium to obtain the colloidal selenium nanoparticles. The method has advantages of simplicity, safety, time-effectiveness, cost-effectiveness, high yield and eco-friendliness.