Abstract: A photocatalyst suspension reactor for solar fuel formation. The reactor may comprise a shallow pool filled with a first portion of an electrolyte solution. The electrolyte solution may comprise a solvent, a plurality of redox shuttle molecules, and a plurality of photocatalyst particles. The reactor may further comprise a plurality of tubes disposed on a surface of the shallow pool, each tube of the plurality of tubes comprising an upper half and a lower half. The upper half may comprise a transparent material configured to be minimally permeable to hydrogen gas and oxygen gas. The lower half may be configured to be filled with a second portion of the electrolyte solution and comprises an ion bridge material permeable to the plurality of redox shuttle molecules and minimally permeable to the plurality of photocatalyst particles.