Fabrication of Ti-MOF/Ti3C2 heterojunction with boosted activity for visible light-driven photocatalytic degradation

Regulating the separation and transport capabilities of the photocarriers is an important strategy to enhance corresponding activity of photocatalysts. In this work, novel Ti-MOF/Ti 3 C 2 heterojunction with face-to-face intimate contact was design and synthesized through a hydrothermal assemble route. The negatively charged Ti 3 C 2 not only facile the absorb of Ti nodes but also offer rich nucleation sites for the in-situ growth Ti-MOF. Under visible light irradiation, the optimized TM-0.05 exhibited exceptional photocatalytic activity and reusability during tetracycline photocatalytic degradation process. The rate constant reaches 1.83 × 10 −2 min −1 over TM-0.05, which was 5.3 times and 2.3 times higher than that of sole Ti-MOF and Ti 3 C 2 , respectively. Combined photoelectric characterization confirmed the improved photocatalytic activity was predominantly due to the excellent conductivity of Ti 3 C 2 and the tight interface connection between the two semiconductors, thus accelerating the interfacial charge separation and transport. Scavenger experiments, EPR, and LC-MS analysis confirmed the key role of •O 2 - , •OH and photogenerated holes during tetracycline degradation, and finally a possible mechanism was postulated. This work provides a new approach for constructing MOF/MXene structures via in situ self-assembly strategy, and expand their application in refractory pollutants photocatalytic degradation process.