Enhanced visible-light catalytic degradation of methylene blue by improving adsorption of porous zirconium-based porphyrin MOFs sensitized TiO2 photocatalyst

The zirconium-based porphyrin MOFs sensitized TiO 2 (PCN224–TiO 2 ) was synthesized in situ by self-assembly of porphyrin, ZrCl 4 with nano TiO 2 . The composite catalyst was determined by detailed structural and photoelectrochemical characterization. The UV–Vis absorption and fluorescence spectrum confirm that PCN224 and TiO 2 are coupled. The PCN224–TiO 2 had significant absorption of visible light and the PCN224–TiO 2 had the largest photo-generated current, which proved the porphyrin MOFs material has good internal conductivity and has a close combination with TiO 2 . Compared with carboxyphenyl porphyrin sensitized TiO 2 (HTCPP–TiO 2 ), mixture of TCPP and TiO 2 (TCPP/TiO 2 ) and PCN224, the PCN224–TiO 2 showed better removal performance of methylene blue under visible light. Under low-power xenon lamp irradiation, the removal rate of PCN224–TiO 2 (1:3) on methylene blue reached 93.2% in 4 h. And PCN224–TiO 2 had stable cycling catalytic performance. The PCN224–TiO 2 promoted the degradation process by strengthening the adsorption of organic pollutants, thus improving the removal performance. Graphic abstract