Oxygen vacancy and Van der Waals heterojunction modulated interfacial chemical bond over Mo2C/Bi4O5Br2 for boosting photocatalytic CO2 reduction

• Published in: Applied catalysis. B, Environmental Vol. 318; p. 121866
• Main Authors: Peng, Haiyan, Deng, Xiaoxu, Li, Gen, Wang, Qiuchen, Song, Meiyang, Chen, Peng, Yin, Shuang-Feng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.12.2022
• Subjects: CO2 reduction; Heterojunctions; Oxygen vacancy; Photocatalysis; Van der Waals; Heterojunctions; Van der Waals; CO2 reduction; Photocatalysis; Oxygen vacancy
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2022.121866

The establishment of heterojunctions between phase interfaces is an important strategy to enhance catalytic activity, but the behavior of charge transfer and exciton dissociation is unsharpness and significant. Here, a Van der Waals heterojunction (VDWH) of Mo2C/Bi4O5Br2 composite with oxygen vacancies (BM) was synthesized via a facile method. Various experimental results and density functional theory calculations demonstrated that the compact VDWH and unsaturated oxygen vacancy induced interfacial Mo-O bonds to modulate surface electronic structure. Consequently, the electron extracted from the exciton formed a strong internal electric field, which boosted the dissociation of the excitons and charge transfer via the electron transfer channel of the Mo-O bond. Therefore, the BM shows excellent CO2 reduction performance (1277.4 µmol g−1 h−1) and stability without using sacrificial agents and cocatalysts, which is about 6 times of Mo2C/Bi4O5Br2. This work not only gives deep insights into charge separation in VWDH and oxygen vacancy but also provides an efficient photocatalyst for efficient green energy conversion. [Display omitted] •The Bi4O5Br2 and Mo2C VDWH with oxygen-rich defects was prepared by the self-assembly method.•The interfacial Mo-O bonds for modulating surface electronic structure.•The Mo-O bonds could boost the excitons dissociation and charge transfer.•BM materials exhibited excellent photocatalytic activity and stability.