Effect of precursor structure mediated by phthalic acid on the structure and properties of CN

The dicyandiamide/phthalic acid (DCDA/PA) precursor with molecular assembly strategy was prepared by hydrothermal treatment the mixture of dicyandiamine and phthalic acid, in which some of the amines were bound by phthalic acid through hydrogen bonding interactions, and the carbon nitride (CN) photocatalyst was further prepared by thermal polymerization. The results showed that the new chemical structure formed by the interaction of melamine cyanurate and phthalic acid through hydrogen bonding could hinder the intermolecular collision chances during the calcination process of DCDA/PA precursor, which made the polymerization reaction difficult to be carried out, and the CN photocatalysts with irregular layered stacking structure were formed. In addition, the presence of more amino groups in the CN-0.3 structure can effectively improve the separation efficiency of its photogenerated charge carriers, and after simulated visible light irradiation for 60 min, the photocatalytic activity presented by CN-0.3 for MB was 2.72 times higher than that of pristine g-C₃N₄.