Fabrication of a novel type visible-light-driven heterojunction photocatalyst: Metal-porphyrinic metal organic framework coupled with PW12/TiO2

Abstract

Metalloporphyrinic metal-organic framework (PCN-222) is a promising photocatalytic material due to its large surface area and 1D channel, exceptional stability, high visible-light capture capability, and semiconductor properties. Herein, we constructed a highly efficient visible-light-driven type II heterojunction photocatalyst PCN-222-PW12/TiO2 by one step solvothermal method. The 5 wt% PCN-222-PW12/TiO2 showed the superior photocatalytic properties for degrading rhodamine B (RhB) and Ofloxacin, which are 10.69 and 10.48 times higher than pure TiO2 under same conditions. The excellent photocatalytic performance of PCN-222-PW12/TiO2 ternary composite material was attributed to the improved adsorption capacity of organic pollutants, optical absorption in the entire visible light region, and highly-efficient separation of photoinduced carriers. Besides, we found that h+, O2−, and OH are the main active elements in the photocatalytic degradation process. This will back up the higher photocatalytic activity of PCN-222-PW12/TiO2 compared with pure TiO2. The photocatalytic efficiency of composite maintained a similar level of photoactivity after four times recovery, which showed excellent stability and recyclability of PCN-222-PW12/TiO2. This work provides new insights into the fabrication porphyrin-MOF composite materials with high photocatalytic efficiency for environmental remediation.