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

Abstract To reduce the reliance on fossil fuel, H 2 , 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 H 2 –O 2 gas mixture, resulting in increased cost and system design complexity. Here, a solar‐driven H 2 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 H 2 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 O 2 . 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 H 2 generation coupled with co‐production of a high‐value product expediting the transition to a hydrogen economy.