Green Synthesis of TiO2-CeO2 Nanocomposites Using Plant Extracts for Efficient Organic Dye Photodegradation
Quang Ho Dinh, Van Duy Lai, Quỳnh Anh Nguyễn, Dinh Duc Nguyen, Duong Duc La
Abstract
The growing presence of hazardous organic pollutants in wastewater poses severe environmental and health risks, necessitating sustainable and efficient treatment solutions. Traditional remediation methods have limitations, highlighting the need for innovative approaches. A green synthesis method was developed to produce TiO2-CeO2 nanocomposites using Cleistocalyx operculatus leaf extract. The photocatalytic efficiency of the synthesized nanocomposites was evaluated under simulated sunlight by degrading Methylene Blue (MB) dye. Various compositions were tested to determine the optimal performance. The 0.1% TiO2-CeO2 nanocomposite achieved the highest degradation efficiency (95.06% in 150 min) with a reaction rate constant (k) of 18.5 × 10−2 min−1, outperforming commercial TiO2 (P25, 74.85%, k ≈ 3.7 × 10−2 min−1). Additionally, the material maintained excellent stability over eight consecutive cycles with only a slight decrease in efficiency from 95.85% to 93.28%. The enhanced photocatalytic activity is attributed to the synergistic effects of CeO2 incorporation, which enhances charge separation, extends visible light absorption, and promotes reactive oxygen species (ROS) generation. These findings highlight the potential of green-synthesized TiO2-CeO2 nanocomposites as a cost-effective and sustainable solution for wastewater treatment.