It only produces microliters of hydrogen/cm^2 in six hours and the amount of hydrogen produced was cut in half after that. Doesn't sound very promising to me.
It's got a home run but I hope the researchers continue to refine the work. 30% faradic efficiency, even with the material degradation, shows a lot of promise.
It seems like they were using a low intensity light source which could explain the reduced output per cm². I didn't read any specifics about light source or intensity in the original publication.
At 30%, and the fact the output can be stored directly in that form (as hydrogen and oxygen) and used in a fuel cell later when power output is required seems promising.
