The graphene (Gr)/PI (pyromellitic dianhydride (PMDA) modified g-C₃N₄) heterojunction was fabricated by a handy sonochemical method. After adding PMDA in the forming process of g-C₃N₄, the conduction position of obtained catalyst was lowered to −0.59 eV (closer to the Fermi level of Gr), which is beneficial for constructing high-efficient heterojunction with less energy loss. The photocatalytic efficiency of Gr/PI for Rodamine B (RhB) degradation was greatly enhanced compared with Gr/g-C₃N₄. The k of RhB removal on Gr/PI was 1.60 times as that of Gr/g-C₃N₄. The excellent photocatalytic ability of Gr/PI was mainly attributed to the effective separation of photogenerated electron-holes.

石墨烯（Gr）/ PI（均苯四甲酸二酐（PMDA）改性的gC ₃ N ₄）异质结是通过便捷的声化学方法制备的。在gC ₃ N ₄的形成过程中添加PMDA后，所得催化剂的导电位置降低至-0.59 eV（更接近于Gr的费米能级），这有利于构建具有更少能量损失的高效异质结。与Gr / gC ₃ N ₄相比，Gr / PI对罗丹明B（RhB）降解的光催化效率大大提高。在Gr / PI上去除RhB的k是Gr / gC ₃ N _4的1.60倍。Gr / PI的优异的光催化能力主要归因于光生电子空穴的有效分离。