Light-driven hydroiodic acid splitting from semiconductive fuel generator

A device for generating hydrogen gas comprising:

• a chamber compartmentalized to have a first subchamber and a second subchamber;
• an ionomer membrane sealably separating the first subchamber and second subchamber;
• a plurality of elongated structures comprising an Si material extending through the ionomer membrane and having the following parameter(s):
• a bandgap energy of about 0.80 to 1.90 eV,
• each elongated structure having a first end and a second end,
• wherein the first ends of the plurality of elongated structures are n-Si comprising a p+ emitter layer and extend into the first subchamber and wherein the second end of the plurality of elongated structures are undoped n-Si and extend into the second subchamber;
• and
• catalyst disposed on the surface of the first end of elongated structures in the first subchamber, wherein the catalyst on the first end of elongated structure performs the following half reaction:
• 3I−→I3−+2e−,
• catalyst disposed on the second end of elongated structures in the second subchamber, wherein the catalyst on the second end of elongated structure performs a half-reaction:
• 2H++2e−→H2,
• when exposed to light.