Methods of sulfurizing metal containing particles in the absence of hydrogen are described. One method includes contacting a bed of metal containing particles with a gaseous stream comprising hydrogen sulfide and inert gas under reaction conditions sufficient to produce sulfided metal containing particles. The gaseous stream is introduced into a vertical reactor at an inlet positioned at the bottom portion of the reactor and any unreacted hydrogen sulfide and inert gas is removed at an outlet positioned above the inlet. The sulfided metal containing particles can be removed from the reactor and stored.

A bacterially induced crystal particle is formed by a composite shell that encloses a hollow space. The composite shell layer includes a biomaterial and a metallic material. The biomaterial includes cell wall or cell membrane of a bacterium. The metallic material includes oxides, sulfides, selenides, acid salt compounds of a transition metal, or any combination thereof. When the bacterially induced crystal particle is spheric, the composite shell is formed by two dome-shaped portions, and a thickness of each of the dome-shaped portions is not less than 1/73 of a diameter of the bacterially induced crystal particle. Alternatively, when the bacterially induced crystal particle is rod-shaped, the thickness of the dome-shaped portions is not less than 1/73 of a width of the bacterially induced crystal particle, and a thickness of the cylindrical portion is not less than 1/37 of the width of the bacterially induced crystal particle.

A bacterially induced crystal particle is formed by a composite shell that encloses a hollow space. The composite shell layer includes a biomaterial and a metallic material. The biomaterial includes cell wall or cell membrane of a bacterium. The metallic material includes oxides, sulfides, selenides, acid salt compounds of a transition metal, or any combination thereof. When the bacterially induced crystal particle is spheric, the composite shell is formed by two dome-shaped portions, and a thickness of each of the dome-shaped portions is not less than 1/73 of a diameter of the bacterially induced crystal particle. Alternatively, when the bacterially induced crystal particle is rod-shaped, the thickness of the dome-shaped portions is not less than 1/73 of a width of the bacterially induced crystal particle, and a thickness of the cylindrical portion is not less than 1/37 of the width of the bacterially induced crystal particle.

Methods for making of nanomaterials from a bulk source material involve heating the material in an inert atmosphere, whereby a material having at least one nanometer scale dimension is formed on a nearby substrate surface. The heated bulk source material forms a vapor phase which is deposited in the form of the nanomaterial on a growth surface of the substrate. The methods require no complex machinery or devices, unlike chemical vapor deposition, and can be tuned to provide different forms of nanomaterials, such as two-dimensional or other crystalline forms. The methods can be used to make two-dimensional semiconductor materials and semiconductor devices.

A method for synthesizing two-dimensional (2D) nanosheets comprises heating a bulk material in a solvent. The process is scalable and can be used to produce solution-processable 2D nanosheets with uniform properties in large volumes.

A method for synthesizing two-dimensional (2D) nanosheets comprises heating a bulk material in a solvent. The process is scalable and can be used to produce solution-processable 2D nanosheets with uniform properties in large volumes.

Methods of sulfurizing metal containing particles in the absence of hydrogen are described. One method includes contacting a bed of metal containing particles with a gaseous stream comprising hydrogen sulfide and inert gas under reaction conditions sufficient to produce sulfided metal containing particles. The gaseous stream is introduced into a vertical reactor at an inlet positioned at the bottom portion of the reactor and any unreacted hydrogen sulfide and inert gas is removed at an outlet positioned above the inlet. The sulfided metal containing particles can be removed from the reactor and stored.

Methods of sulfurizing metal containing particles in the absence of hydrogen are described. One method includes contacting a bed of metal containing particles with a gaseous stream comprising hydrogen sulfide and inert gas under reaction conditions sufficient to produce sulfided metal containing particles. The gaseous stream is introduced into a vertical reactor at an inlet positioned at the bottom portion of the reactor and any unreacted hydrogen sulfide and inert gas is removed at an outlet positioned above the inlet. The sulfided metal containing particles can be removed from the reactor and stored.

A method for manufacturing bacterially induced crystal particle includes culturing bacteria in a culture medium including a carbon source and a raw metal material including a transition metal, so that the bacteria induce a raw metal material to undergo a reduction-oxidation reaction; isolating a wet powder material from the culture medium; and drying the wet powder material to obtain a powder material. The powder material includes at least one bacterially induced crystal particle.

A method for manufacturing bacterially induced crystal particle includes culturing bacteria in a culture medium including a carbon source and a raw metal material including a transition metal, so that the bacteria induce a raw metal material to undergo a reduction-oxidation reaction; isolating a wet powder material from the culture medium; and drying the wet powder material to obtain a powder material. The powder material includes at least one bacterially induced crystal particle.