Self-assembled meso-tetra(4-carboxyphenyl)porphine: Structural modulation using surfactants for enhanced photoelectrochemical properties

Porphyrin based nanomaterials have attracted widespread attention due to their similarity of the key dyes of natural photosynthesis. To develop new chromophores for photoelectrochemical (PEC) devices, in this work, we synthesized 3 different aggregated nanostructures of meso-tetra(4-carboxyphenyl)porphine (TCPP) via self-assembly technique. The micro-environments of porphyrin self-assembly were modulated by using sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) as “soft template” respectively, aqueous solution without surfactant as control. Due to the different driving forces of self-assembly, the as-prepared TCPP nanostructures exhibited remarkably different morphologies, electrochemical and PEC properties. Among them, the self-assembled TCPP using SDS (SA-TCPP/SDS) possessed enhanced PEC performance. In presence of dopamine, a significant photocurrent response can be feasibly obtained in aqueous media at −0.4 V (vs. Ag/AgCl). Moreover, the self-assembly process was also investigated using in situ UV–visible spectroscopy and the corresponding structure formation mechanisms were proposed.