A post-synthetically modified porous organic polymer for photocatalytic water purification

The incremental discharge of chemicals and textile waste into industrial effluents makes water unbearably polluted for humans and other living organisms. Conventional water treatment processes are efficient in degrading stable conjugated organic dye molecules. Therefore, sustainable technology for degrading toxic organic pollutants is in continuous demand. Heterogeneous photocatalytic degradation of organic pollutants has been advantageous because of its cost-effectiveness and recycling abilities. Herein, we developed a new porphyrin-based porous organic polymer (PNP) and modified it with platinum clusters to get the Pt@PNP which is endowed with enhanced photocatalytic degradation efficiency of toxic organic dyes in water. It effectively decomposed carcinogenic organic dyes methyl orange (MO) and rhodamine B (Rh B) into smaller organic compounds by generating reactive oxygen species (ROS) under mild light irradiation. The significant enhancement in the photocatalytic efficiency can be ascribed to the fine-tuned band positions of PNP and Pt clusters resulting in increased light absorption and restricted charge recombination. After the water purification process, this heterogeneous photocatalyst was also found to be easily separable and robust in recycling without any significant activity loss. This work presents an efficient method to enhance the porous organic polymer's (POP's) photocatalytic activity and pave the way to the development of photocatalytic water purification devices using modified POPs.