Versatile g-CN/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-CN/AlOOH photocatalytic nanocomposites via thermal condensation, enhancing adsorption and visible light degradation by 36-fold and 11-fold, respectively, compared to g-CN alone. The nanocomposites achieved a 98% removal rate of methyl orange under xenon lamp irradiation (>400 nm) for 1 h. 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 h of photocatalyzing by g-CN/AlOOH, doubling that of g-CN 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-CN-AlOOH heterostructures, high surface potential, and Type II heterojunctions, which reduce electron-hole pair recombination. Furthermore, g-CN/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.