Chlorophyll sensitization of green-synthesized TiO2 nanoparticles for visible light activation to purify wastewater

Water is essential for all life forms, yet industrial effluents from sectors such as textiles, pharmaceuticals, and food processing release persistent organic pollutants that severely degrade water quality. Contaminated water causes nearly five million deaths annually, and around two billion people still lack access to safe drinking water. Conventional wastewater treatment methods often fail to remove resistant pollutants, prompting interest in advanced oxidation processes (AOPs), which generate reactive radicals for pollutant degradation. Among AOPs, photocatalysis stands out for its ability to mineralize contaminants into harmless CO₂ and H₂O with minimal sludge. Titanium dioxide (TiO₂) is a popular photocatalyst due to its abundance, stability, and non-toxicity, but its wide bandgap limits activity to UV light, which is only a small portion of sunlight. Therefore, modifying TiO₂ to enhance visible-light activity through eco-friendly synthesis and surface modifications is crucial. Strategies include doping, composite formation, and dye sensitization. Natural dyes like chlorophyll and anthocyanin are promising, green alternatives to costly and toxic synthetic dyes. This study explores the green synthesis of TiO₂ nanoparticles using chickpea peel extract and their chlorophyll sensitization from pomelo leaves to efficiently degrade organic pollutants in real wastewater under visible light.

• Research Project