Lithium-Doped Graphitic Carbon Nitride: Optimized Design for Visible-Light Photocatalytic Application
Dhavalkumar Bhanderi, Pratikkumar Lakhani, Vandana Rao, Ashita Sharma, Saurabh S. Soni, Chetan K. Modi
Abstract
In this study, visible-light-responsive photocatalysts were developed by doping lithium (at varying concentrations of 5%, 10%, and 15%) onto graphitic carbon nitride (g-C 3 N 4 ) nanosheets synthesized by using urea and dicyandiamide as precursors, resulting in Li@g-C 3 N 4 catalysts. These catalysts demonstrated exceptional photocatalytic performance in the synthesis of 4 H -chromenes under visible LED light (60 W), outperforming that of pristine g-C 3 N 4 . Comprehensive characterization of the photocatalysts was conducted using techniques such as FT-IR, XRD, XPS, TEM, EIS, Mott–Schottky analysis, photocurrent density measurements, UV–vis DRS, and SEM. Among the catalysts, Li@g-C 3 N 4 with 15% lithium loading achieved the highest efficiency, yielding 96% of 2-amino-7-hydroxy-4-(4-(trifluoromethyl)phenyl)-4 H -chromene-3-carbonitrile. Additionally, this catalyst was tested with various benzaldehyde derivatives, yielding products with efficiencies ranging from 80% to 96%. The catalyst also exhibited excellent stability with minimal activity loss after five recyclability cycles. This work establishes Li@g-C 3 N 4 as a highly efficient and sustainable material for photocatalytic applications.