Construction of Ti3C2/ZnTCPP/CTFs Ohmic/S-scheme hybrid heterojunction with robust built-in electric field for boosting photocatalytic hydrogen evolution

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2023-11, Vol.676, p.132198, Article 132198
• Main Authors: Qin, Xiang, Ji, Lijun, Zhu, Aiping
• Format: Article
• Language: English
• Subjects: Covalent triazine frameworks; Hydrogen production; Porphyrins; Ti3C2 MXene
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2023.132198

A heterostructure of Ti3C2/ZnTCPP/CTFs was constructed by the freeze-drying method and steam-assisted method. In visible light, the hydrogen evolution rate of Ti3C2/ZnTCPP/CTFs-3 was 6.2 times that of ZnTCPP, 4.4 times that of CTFs, 5.6 times that of Ti3C2/ZnTCPP and 1.7 times that of Ti3C2/CTFs. The hydrogen evolution rate of the optimized ternary composite reached 462.6 μmol·g−1·h−1, and the quantum efficiency at 420 nm was 3.34 %. At the same time, the ternary photocatalyst showed high stability. The strong S-type interfacial electric field promoted the separation of space charges between ZnTCPP and CTFs effectively. The two-dimensional Ti3C2 nanosheets, as an Ohmic-junction H2-evolution co-catalyst, provided more electron transfer pathways and a large number of active sites for photocatalysis. This work provides some new ideas and enlightenment for the rational design of efficient Ohmic/S-scheme heterojunction photocatalysts. [Display omitted] •A Ti3C2/ZnTCPP/CTFs Ohmic/S-scheme heterojunction was reported for the first time.•The interfacial electric field between ZnTCPP and CTFs promoted charge separation.•Ti3C2 promoted the separation and transfer of photogenerated electrons.•The S-scheme photocatalytic mechanism of the heterojunction was proposed.