Photoassisted Oxygen Reduction Reaction in H2–O2 Fuel Cells

Abstract The oxygen reduction reaction (ORR) is a key step in H 2 –O 2 fuel cells, which, however, suffers from slow kinetics even for state‐of‐the‐art catalysts. In this work, by making use of photocatalysis, the ORR was significantly accelerated with a polymer semiconductor (polyterthiophene). The onset potential underwent a positive shift from 0.66 to 1.34 V, and the current was enhanced by a factor of 44 at 0.6 V. The improvement was further confirmed in a proof‐of‐concept light‐driven H 2 –O 2 fuel cell, in which the open circuit voltage ( V oc ) increased from 0.64 to 1.18 V, and the short circuit current ( J sc ) was doubled. This novel tandem structure combining a polymer solar cell and a fuel cell enables the simultaneous utilization of photo‐ and electrochemical energy, showing promising potential for applications in energy conversion and storage.