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

Abstract

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.