 This study investigates the charge transfer dynamics between two phases of a crystalline triazine-heptazine-carbon nitride hetero structure. The researchers use a combination of surface bimetallic cocatalysts and in situ photoemission spectroscopy to trace the S-scheme charge transfer process. They find that the S-scheme charge transfer pathway is reversed when the sample is exposed to light or dark environments. This reversal is supported by theoretical calculations, which suggest that the reversal is caused by the change in the energy levels at the molecules. Additionally, the researchers show that the S-scheme charge transfer can be used to enhance the efficiency of CO2 reduction reactions. This article was offered by Fang Li, Xiaoyang Yu, Yulong Liao, and others.