In a recent study featured in the journal Environmental Science and Ecotechnology, scientists hailing from the Harbin Institute of Technology have unveiled an innovative double Z-scheme photocatalyst named the molecularly imprinted TiO2@Fe2O3@g-C3N4 (MFTC) composite, tailored specifically for the targeted removal of SMX from water.
Conventional photocatalytic techniques have grappled with the challenge of selectivity, often leading to the indiscriminate breakdown of organic pollutants and coexisting contaminants, particularly when present in high concentrations. However, the MFTC composite was meticulously engineered to surmount this limitation by incorporating molecularly imprinted sites on its surface. These specialized sites possess a unique capacity to recognize and enhance the adsorption of sulfamethoxazole (SMX), rendering the MFTC exceptionally adept at singling out SMX in the presence of other contaminants such as sulfadiazine (SDZ), ibuprofen (IBU), and bisphenol A (BPA). In simulated wastewater conditions, the MFTC composite showcased an impressive selective degradation efficiency rate of 96.8% for SMX, nearly twice as effective as rival catalysts for handling other pollutants.
The “lock and key” mechanism inherent to the molecularly imprinted sites played a pivotal role in selectively capturing SMX, resulting in superior performance. The degradation process of SMX by the MFTC photocatalytic system entailed the generation of •OH and •O2− free radicals, thereby expediting the removal of SMX through a novel double Z-scheme mechanism. This mechanism substantially bolstered the transfer and separation of charge carriers, thereby resulting in significantly enhanced photocatalytic activity.
Furthermore, the MFTC composite exhibited remarkable stability and recyclability across multiple cycles, making it a highly promising and practical solution for water treatment applications. The outstanding performance and selectivity of the MFTC composite hold great promise for advancing efficient and selective photocatalysts, thereby contributing to the development of eco-friendly and cost-effective solutions for water purification and environmental remediation.
This research not only furnishes invaluable insights into the selective elimination of sulfamethoxazole (SMX) but also paves the way for further exploration of molecularly imprinted nanocomposite materials aimed at selectively eradicating other pharmaceutical residues and organic pollutants.