An overview on cellulose-supported photocatalytic materials for the efficient removal of toxic dyes

Recently, the concept of green chemistry has emerged as a novel and efficient way for environmental remediation. Amongst several biomaterials, cellulose is the most widely utilized natural biopolymer and significant adsorbent due to its unique and exceptional characteristics such as biodegradability, biocompatibility, reproducibility, non-toxicity, cost-effectiveness, increased specific area, greater interaction between active sites and pollutants, and high adsorption capacity. On the other hand, photocatalysis, an advanced water purification technique accelerates chemical reactions in the presence of light. But, the photocatalysts are inherited with certain limitations like low surface area for adsorption, charge carriers’ recombination rate, etc. In this regard, the combination of cellulose with other photocatalysts typically results in adsorptional photocatalysis which improved porosity, surface area, and photocatalytic efficacy of photocatalysts. Cellulose serves as a support material and acts as an electron mediator that effectively enhanced charge carrier’s migration ability and decreases their recombination rate. Hence, the current review mainly focuses on the incorporation of cellulose materials with various photocatalysts to enhance their photocatalytic efficiency. Also, the review briefly discussed the structural properties and various types of cellulose biomaterials as well as various types of harmful dyes with their hazardous effects. Additionally, the photocatalytic efficacy of various metal-oxides, metal-sulfides, metal-free photocatalysts, and cellulose-supported photocatalysts was explored with mechanistic insights toward the photodegradation of toxic dyes.