Solar‐Driven Co‐Production of Hydrogen and Value‐Add Conductive Polyaniline Polymer

To reduce the reliance on fossil fuel, H2, as a clean fuel, has attracted substantial research and development activities in recent years. The traditional water splitting approach requires an applied bias of more than 1.5 V and the use of ion‐selective membranes to prevent the formation of a potentially explosive H2–O2 gas mixture, resulting in increased cost and system design complexity. Here, a solar‐driven H2 production process requiring a much lower applied bias of 1.05 V is reported whereby aniline (ANI) is oxidized to polyaniline (PANI) at the anode with a yield of 96% and H2 evolution reaction occurs at the cathode with a faradaic efficiency of 98.6 ± 3.9%. The process has multiple advantages including the elimination of ion‐exchange membrane as PANI is a solid product that also is of substantially higher value than O2. For demonstration, a single junction perovskite solar cell and low‐cost earth abundant CoP catalyst are successfully applied for this process. This process contributes to the advancement of solar‐driven low‐cost H2 generation coupled with co‐production of a high‐value product expediting the transition to a hydrogen economy. A solar‐driven process with co‐production of H2 and a value‐add conductive polyaniline (PANI) polymer is reported. Compared to conventional water splitting, this process is driven at a lower applied bias of 1.05 V without the use of ion‐exchange membrane producing PANI with a higher value than O2.