▎ 摘　　要

The acid-base chemistry of cationic 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin (TMPyP) and graphene oxide (GO) complex was studied in aqueous solution using absorption and fluorescence spectroscopy. By varying the pH from 0 to 13, we controlled the electrostatic properties of TMPyP and/or GO. The neutrality on GO or negative charge on TMPyP induced the dissociation of the TMPyP/GO complex, indicating that the electrostatic attractive force is indispensable for both forming and preserving the complex. Furthermore, our results suggest that the molecular flattening of the TMPyP in the TMPyP/GO complex is mainly caused by the pi-pi interaction.