Construction of 2D Co-TCPP MOF decorated on B-TiO2-X nanosheets: Oxygen vacancy and 2D-2D heterojunctions for enhancing visible light-driven photocatalytic degradation of bisphenol A

Visible light driven photocatalytic degradation of organic pollutants, such as bisphenol A (BPA) in wastewater, is considered as a promising strategy to solve the environmental issue. A two-dimensional (2D) porphyrin Co-TCPP MOF decorated 2D B-TiO2-X nanosheet was successfully prepared through a facile hydrothermal method. The 2D-2D heterostructure could give rise to a built-in electric field to effectively promote the interfacial charge transfer and separation of photogenerated electron and holes. The presence of oxygen vacancy in the as-prepared heterostructure could greatly enhance the visible light harvesting ability to generate more photogenerated carriers. The Co-TCPP MOF@B-TiO2-X exhibited remarkable photocatalytic performance for the degradation of BPA, whose degradation rate was up to 97% within 120 min irradiation. The degradation efficiency of this composite was 7.3 and 19.3 times higher than those of single Co-TCPP MOF and B-TiO2-X respectively. The intimate contact between B-TiO2-X and Co-TCPP MOF reduced interface resistance for charge migration, prolonged photoelectron lifetime and facilitated the charge carriers' separation. The trapping tests verified that center dot O-2(-) was the mainly active species of BPA degradation. This strategy not only proves that the combination of B-TiO2-X and Co-TCPP MOF is a feasible strategy to improve the photocatalytic degradation of BPA, but also provides some new inspirations for the construction of efficient 2D-2D composite photocatalysts.

Automated summary

The 2D porphyrin Co-TCPP MOF decorated 2D B-TiO2-X nanosheet exhibited remarkable photocatalytic performance for the degradation of organic pollutants, with the heterostructure effectively promoting interfacial charge transfer and separation of photogenerated carriers, leading to enhanced visible light harvesting ability.