Understanding the unique S-scheme charge migration in triazine/heptazine crystalline carbon nitride homojunction

• الحاوية / القاعدة: Nature Communications
• المؤلفون الرئيسيون: Fang Li, Xiaoyang Yue, Yulong Liao, Liang Qiao, Kangle Lv, Quanjun Xiang
• التنسيق: مقال
• اللغة: الإنجليزية
• منشور في: Nature Portfolio 2023-07-01
• الوصول للمادة أونلاين: https://doi.org/10.1038/s41467-023-39578-z

Abstract Understanding charge transfer dynamics and carrier separation pathway is challenging due to the lack of appropriate characterization strategies. In this work, a crystalline triazine/heptazine carbon nitride homojunction is selected as a model system to demonstrate the interfacial electron-transfer mechanism. Surface bimetallic cocatalysts are used as sensitive probes during in situ photoemission for tracing the S-scheme transfer of interfacial photogenerated electrons from triazine phase to the heptazine phase. Variation of the sample surface potential under light on/off confirms dynamic S-scheme charge transfer. Further theoretical calculations demonstrate an interesting reversal of interfacial electron-transfer path under light/dark conditions, which also supports the experimental evidence of S-scheme transport. Benefiting from the unique merit of S-scheme electron transfer, homojunction shows significantly enhanced activity for CO2 photoreduction. Our work thus provides a strategy to probe dynamic electron transfer mechanisms and to design delicate material structures towards efficient CO2 photoreduction.