Effect of hydrogen bond interaction in precursor on photocatalytic oxidation of MB by C-GA/g-C3N4 composites

It is well known that the design of precursor structure is an effective method to optimize the photocatalytic activity of g-C 3 N 4 , and it will be interesting to investigate the relationship between the precursor structure and the structure of the target catalyst. In this paper, by adjusting the addition amount of glutaraldehyde (GA), three kinds of glutaraldehyde/dicyandiamide (GA/DCDA) precursors with equilibrium/imbalance hydrogen bond interaction can be obtained, and the carbonized glutaraldehyde (C-GA)/g-C 3 N 4 composite catalysts with different carbon content can be obtained after calcination. The obtained C-GA/g-C 3 N 4 composite catalysts have different photocatalytic activity for methylene blue degradation. Compared with the original g-C 3 N 4 , the photocatalytic activity of C-GA/g-C 3 N 4 -2 composite is increased by 2.69 times. Through the analysis of thermal decomposition kinetics and structural characterization, we can see that the equilibrium interaction in the structure of GA/DCDA-2 precursor can promote the conversion of dicyandiamide to melamine, and glutaraldehyde carbonization will form more C-GA, and form a composite catalyst with closer interaction with g-C 3 N 4 . C-GA with close interaction and higher content can effectively promote the separation of photogenerated carriers and visible light absorption, thus improving its photocatalytic activity.