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

Abstract 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 ·O2- 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.