Solvent assisted shape dependent MAPbI3/polyfluorene heterostructures with a larger surface area for improved photocatalytic H2 evolution

Abstract

Although lead based MAPbI₃ has been used as a material for photocatalytic hydrogen evolution, conventionally synthesized MAPbI₃ in HI solution suffers from very low HER activity with a hydrogen evolution rate of 30 μmol h⁻¹ g⁻¹. Several efforts have been made to boost the HER performance by tagging a co-catalyst. But no such significant approach was developed to improve the HER activity of pristine MAPbI₃. In this work, the shape and morphology of MAPbI₃ have been modified by a simple solvent change route. This led to substantial transformation in shape and morphology affecting various facets of photocatalytic and photoelectrochemical performance. DMF assisted pristine MAPbI₃ exhibited an HER activity of 830 μmol h⁻¹ g⁻¹, almost 28-fold better than that of typical HI based MAPbI₃. This work highlights how solvent transition from HI to DMF can influence the shape and surface morphologies which impact the photocatalytic and photoelectrochemical performances of pristine MAPbI₃. To further enhance the HER activity of DMF assisted MAPbI₃, the as-synthesized polyfluorene co-catalyst was integrated on the MAPbI₃ surface. Under optimized conditions, the hydrogen evolution of MAPbI₃/polyfluorene composites can reach up to 6200 μmol h⁻¹ g⁻¹.