Photocatalytic Activity of Iron-Doped Titania Coupled with Biochar for Wastewater Treatment

The photocatalytic activity of iron-doped titania nanoparticles under visible light was enhanced through coupling with biochar. Preliminary tests evaluated the adsorption capacities of biochar derived from various sources, including coffee grounds, mate wood, deglet noir date pits, and licorice roots. Based on these results, different synthesis strategies were explored to select the most effective catalyst for degrading methylene blue, paracetamol, and methyl orange, which represent cationic, neutral, and anionic contaminants, respectively. The most effective catalyst was identified as an iron-doped nano-titania coupled with licorice-derived biochar, produced via an innovative solid-state synthesis method that is both waste-free and efficient. This composite catalyst performance was compared with a similar catalyst lacking biochar. Among the biochar sources tested, licorice biochar demonstrated the highest adsorption capacity and significantly enhanced the photocatalytic activity of the iron-doped titania. Results indicated that the composite catalyst was most effective in degrading cationic contaminants, while its efficiency for neutral and anionic molecules was comparatively lower.