Schiff-base-rich g-CxN4 supported PdAg nanowires as an efficient Mott-Schottky catalyst boosting photocatalytic dehydrogenation of formic acid

Developing an efficient photocatalyst, catalyzing formic acid (FA) dehydrogenation, can satisfy the demand of the H-2 energy. Herein, a graphitic carbon nitride (g-CxN4)-based nanosheet (x = 3.2, 3.6 or 3.8) with melem rings conjugated by Schiff-base bond (N=C-C=N) was synthesized, tuning the bandgaps (E-g) of graphitic carbon nitride (g-C3N4) in the range of 1.8 < E-g < 2.7 eV, and grown PdAg nanowires (NWs) on its surface forming an efficient PdAg NWs/g-CxN4 Mott-Schottky heterojunction for enhancing dehydrogenation photocatalysis of FA. The boosting photocatalysis benefits from the Schiff-base bond tuning the E-g of g-C3N4 and strongly coupling from the heterojunction. Among the heterojunction, the Pd5Ag5 NWs/g-C3.6N4 exhibits the best dehydrogenation photocatalysis of FA [turnover frequency (TOF) = 1230 h(-1)] under visible light (lambda > 400 nm) without any additive at 25 degrees C, which is the best value among ever-reported ones. This work provides a new strategy to boost dehydrogenation photocatalysis of FA, which will be promising for practical application of H-2 in future energy field.

Automated summary

The study found that the synthesized Pd5Ag5 NWs/g-C3.6N4 heterojunction exhibits the best dehydrogenation photocatalysis of formic acid without any additive at 25 degrees Celsius under visible light.