Cellulose as a photocatalyst support material: extraction, structural features, and environmental applications

Cellulose is the most abundant and renewable biopolymer found in nature, primarily derived from plant biomass. Its wide availability, low cost, biodegradability, and non-toxic nature make it a promising candidate for sustainable material development across various industries. This review focuses on the extraction and isolation of cellulose from different types of biomass waste, including agricultural residues, forestry byproducts, and industrial waste. Several conventional and advanced methods for cellulose extraction were also explored such as acid hydrolysis, enzymatic hydrolysis, oxidation, and mechanical or solvent-based techniques. Besides that, this review highlights the role of cellulose in photocatalytic applications, where its high surface area, structural porosity, and abundance of functional groups enable it to act as an effective support matrix for photocatalysts such as ZnO, TiO₂, Cu₂O, and various hybrid nanocomposites. Through stabilizing nanoparticles, preventing their aggregation and contributing to pollutant adsorption, cellulose enhances the overall efficiency of photocatalytic systems, improving its performance under a wide range of light sources. Moreover, cellulose-supported systems often show enhanced recyclability and mechanical durability, making them suitable for repeated use in wastewater treatment and environmental remediation. The relationship between cellulose's structural properties and photocatalytic functionality offers a green and efficient solution to pressing environmental challenges. Overall, this review underscores the importance of cellulose not only as a raw material but also as an active component in next-generation, eco-friendly photocatalytic technologies.