Versatile g-C₃N₄/AlOOH Nanocomposites: Efficient photocatalyst for Dye Removal, Algae Inactivation, and Glucose Detection

Visible light photocatalysts hold great promise for water purification, yet research on highly efficient, non-toxic photocatalysts is limited. This study synthesized novel g-C₃N₄/AlOOH photocatalytic nanocomposites via thermal condensation, enhancing adsorption and visible light degradation by 36-fold and 11-fold, respectively, compared to g-C₃N₄ alone. The nanocomposites achieved a 98% removal rate of methyl orange under xenon lamp irradiation (>400 nm) for 1 hour. This study marked the first demonstration of using a low-power LED (0.6W) for photocatalytic algae inactivation in an aquarium ecosystem. Fluorescence spectroscopy showed a 98.9% removal efficiency of chlorophyll a after 12 hours of photocatalyzing by g-C₃N₄/AlOOH, doubling that of g-C₃N₄ alone. Algae inactivation was attributed to rupture, dehydration, and changes in dissolved organic matter. Hole (h⁺) trapping experiments identified them as the primary active species for degrading methyl orange and algae. Materials analyses confirmed the formation of g-C₃N₄-AlOOH heterostructures, high surface potential, and Type II heterojunctions, which reduce electron-hole pair recombination. Furthermore, g-C₃N₄/AlOOH demonstrated selective non-enzymatic fluorescence detection of glucose, showing a linear relationship in 0∼4 mM, suitable for tears glucose detection. This study offers crucial insights and strategies for designing novel, non-toxic, high-performance visible light photocatalytic materials, efficient dye degradation, algae inactivation, and selective glucose detection.