Photocatalytic cell and hydrogen gas generation system

Abstract

A photocatalytic cell of the disclosure is installed in an inclined manner at an angle of 5° or more and 45° or less with respect to a horizontal plane. The photocatalytic cell includes: a translucent member; an electrolytic solution; a photocatalytic sheet including photocatalytic particles; an injection port through which the electrolytic solution is injected into an inside of the photocatalytic cell; a discharge port through which the electrolytic solution is discharged to an outside of the photocatalytic cell; and an exhaust port through which gas inside the photocatalytic cell is discharged, at least a part of the photocatalytic sheet is immersed in the electrolytic solution, a position of the exhaust port is higher than a position of the injection port, a gap between a surface of the translucent member and a surface of the photocatalytic sheet is 5 mm or more and 50 mm or less in width, and the injection port and the discharge port allow the electrolytic solution to flow from an upper part toward a lower part in the gap between the translucent member and the photocatalytic sheet.

1 . A photocatalytic cell installed in an inclined manner at an angle of 5° or more and 45° or less with respect to a horizontal plane,
 the photocatalytic cell comprising: a translucent member that takes in light from an upper side or an obliquely upper side; an electrolytic solution housed in the photocatalytic cell; a photocatalytic sheet including photocatalytic particles that receive the light taken in from the translucent member; an injection port through which the electrolytic solution is injected into an inside of the photocatalytic cell; a discharge port through which the electrolytic solution is discharged to an outside of the photocatalytic cell; and an exhaust port through which gas inside the photocatalytic cell is discharged, wherein 
 at least a part of the photocatalytic sheet is immersed in the electrolytic solution, 
 a position of the exhaust port is higher than a position of the injection port, 
 a gap between a surface of the translucent member and a surface of the photocatalytic sheet is 5 mm or more and 50 mm or less in width, and 
 the injection port and the discharge port allow the electrolytic solution to flow from an upper part toward a lower part in the gap between the translucent member and the photocatalytic sheet. 
 
     
     
         2 . The photocatalytic cell according to  claim 1 , wherein
 the electrolytic solution contains a first cation, and   the electrolytic solution and the photocatalytic particles allow the first cation to be reduced to a second cation by photocatalytic activity of the photocatalytic particles produced by receiving light.   
     
     
         3 . The photocatalytic cell according to  claim 2 , wherein
 the first cation is a trivalent iron ion, and   the second cation is a divalent iron ion.   
     
     
         4 . The photocatalytic cell according to  claim 1 , wherein the position of the exhaust port is higher than the position of the injection port by 10 mm or more. 
     
     
         5 . The photocatalytic cell according to  claim 1 ,
 wherein the photocatalytic particles include tungsten oxide particles.   
     
     
         6 . A hydrogen gas generation system comprising: the photocatalytic cell according to  claim 2 ; and an electrolyzer including a cathode and an anode, the electrolyzer generating hydrogen gas from water or hydrogen ions at the cathode, and oxidizing a second cation to a first cation at the anode,
 wherein the photocatalytic cell and the electrolyzer allow an electrolytic solution containing the second cation generated in the photocatalytic cell to be supplied to the electrolyzer, and an electrolytic solution containing the first cation generated at the anode to be supplied to the photocatalytic cell.