Devices for hydrogen production and methods of fabricating a hydrogen catalyst layer

Abstract

Disclosed herein are devices for hydrogen production and methods of fabricating hydrogen catalyst layers. The method may comprise forming on a substrate a first horizontal crystal and a first standing crystal that include each molybdenum oxide; forming a second horizontal crystal, a second standing crystal, and a preliminary layer on the second horizontal and standing crystals by supplying a sulfur gas onto the first horizontal crystal and the first standing crystal, the preliminary layer including molybdenum disulfide (MoS 2 ); and removing the second horizontal crystal and the second standing crystal.

What is claimed is: 
     
         1 . A method of fabricating a hydrogen catalyst layer, the method comprising:
 providing a substrate comprising a first horizontal crystal and a first standing crystal that each include molybdenum oxide;   forming a second horizontal crystal, a second standing crystal, and a preliminary layer on the second horizontal and second standing crystals by supplying a sulfur gas onto the first horizontal crystal and the first standing crystal, the preliminary layer including molybdenum disulfide (MoS 2 ); and   removing the second horizontal crystal and the second standing crystal.   
     
     
         2 . The method of  claim 1 , wherein forming the second horizontal crystal and the second standing crystal includes reducing at least a portion of oxygen atoms in the first horizontal crystal and in the first standing crystal. 
     
     
         3 . The method of  claim 1 , wherein the second horizontal crystal and the second standing crystal include molybdenum dioxide (MoO 2 ). 
     
     
         4 . The method of  claim 1 , wherein the molybdenum oxide in the first horizontal crystal and the first standing crystal has a chemical formula of Mo a O b , wherein a and b are each independently an integer equal to or greater than 1, and a ratio of b/a is from 2 to 3. 
     
     
         5 . The method of  claim 1 , wherein providing the substrate comprising the first horizontal crystal and the first standing crystal includes supplying the substrate with an inert gas and a molybdenum oxide gas. 
     
     
         6 . The method of  claim 1 , wherein removing the second horizontal crystal and the second standing crystal includes spraying the substrate with an etchant that etches the second horizontal crystal and the second standing crystal. 
     
     
         7 . The method of  claim 1 , wherein forming the second horizontal crystal and the second standing crystal includes increasing a temperature of the substrate. 
     
     
         8 . A method of fabricating a hydrogen catalyst layer, the method comprising:
 forming on a substrate a first horizontal crystal and a first standing crystal that each include molybdenum dioxide (MoO 2 );   forming a preliminary layer on the first horizontal crystal and the first standing crystal; and   removing the first horizontal crystal and the first standing crystal,   wherein the preliminary layer includes molybdenum disulfide (MoS 2 ).   
     
     
         9 . The method of  claim 8 , wherein the first horizontal crystal extends in a first direction that is parallel to a top surface of the substrate, and
 the first standing crystal extends in a second direction that intersects the top surface of the substrate.   
     
     
         10 . The method of  claim 8 , wherein forming the preliminary layer on the first horizontal crystal and the first standing crystal includes supplying a sulfur gas onto the substrate. 
     
     
         11 . The method of  claim 8 , wherein forming on the substrate the first horizontal crystal and the first standing crystal includes:
 forming on the substrate a second horizontal crystal and a second standing crystal; and   reducing at least a portion of oxygen atoms in the second horizontal crystal and in the second standing crystal.   
     
     
         12 . The method of  claim 8 , wherein removing the first horizontal crystal and the first standing crystal includes spraying the substrate with an etchant that etches the first horizontal crystal and the first standing crystal. 
     
     
         13 . The method of  claim 8 , wherein removing the first horizontal crystal and the first standing crystal includes forming a standing structure,
 wherein the standing structure includes:   a first standing segment that extends in a direction intersecting a top surface of the substrate;   a second standing segment that extends in the direction intersecting the top surface of the substrate; and   a first void between the first standing segment and the second standing segment.   
     
     
         14 . The method of  claim 13 , wherein the first standing segment and the second standing segment are parallel to each other. 
     
     
         15 . A device for hydrogen production, the device comprising:
 a substrate;   a horizontal structure that lies on the substrate and extends in a first direction that is parallel to a top surface of the substrate; and   a first standing structure and a second standing structure that each extend in a direction that intersects the top surface of the substrate,   wherein each of the first and second standing structures includes:
 a first standing segment and a second standing segment that are parallel to each other; and 
 a first void between the first standing segment and the second standing segment, 
   wherein extending directions of the first and second standing structures cross each other.   
     
     
         16 . The device of  claim 15 , wherein the horizontal structure, the first standing segment, and the second standing segment each include molybdenum disulfide (MoS 2 ). 
     
     
         17 . The device of  claim 15 , wherein a thickness of each of the first and second standing segments is less than a shortest interval between the first standing segment and the second standing segment. 
     
     
         18 . The device of  claim 15 , wherein the first standing segment includes a first inner sidewall facing the second standing segment,
 the second standing segment includes a second inner sidewall facing the first standing segment, and   the first void completely exposes the first and second inner sidewalls.   
     
     
         19 . The device of  claim 15 , wherein the horizontal structure, the first standing segment, and the second standing segment each have a plate shape. 
     
     
         20 . The device of  claim 15 , wherein a second void is provided between the first standing structure and the second standing structure.