A comprehensive review on the photocatalysis of Congo red dye for wastewater treatment

Abstract Congo red (CR) dye, due to its structural stability and non-degradable nature, is hazardous for humans and the aquatic environment. Among various methods used for degradation of CR, photocatalysis have been widely reported as a cost effective and environment-friendly method. Besides, extensive studies have been carried out regarding the use of nanomaterial-based photocatalyst for degradation of CR. This review describes the basics of photocatalysis along with the factors affecting the process, mechanism, and kinetics in detail. Additionally, literature related to synthetic and bio-based stabilizing mediums in photocatalytic assemblies have been arranged in a systematic manner. Advanced hybrid materials, i.e., metal–organic frameworks (MOFs) have also been described briefly. Future directions are discussed to address existing shortcomings in this field and also to expand research in this area.