Efficient visible light catalytic degradation of toxic organic pollution by hollow urchin-like TiO2@g-C3N4/GQDs composite

Abstract

In order to expand the photoresponsive spectrum of TiO2 and improve its catalytic activity under visible light, the hollow urchin-like composites of TiO2@g-C3N4/GQDs (TCN/GQDs) with a core-shell structure heterojunction was synthesized through a hydrothermal method and calcination. Potassium titanium oxalate, melamine, and citric acid were utilized as the raw materials for this synthesis process. The TCN/GQDs composites were subjected to a range of analyses to examine their microstructure and photoelectric properties. The findings indicated that the synthesized composites effectively enhanced the absorption spectrum of TiO2 in the visible light range by creating the stable heterojunctions among TiO2, g-C3N4 and GQDs. Additionally, the ability of these composites to degrade toxic organic pollutants under visible light was studied by using several different organic dyes and antibiotics. The results demonstrated that the TCN/GQDs composites exhibited efficient visible light catalytic degradation capability on organic pollutants, and the degradation efficiency could approach to 100 % under visible light in a short time. Furthermore, the photocatalyst exhibited hardly change of degradation efficiency towards organic pollutants even after 5 cycles of testing, suggesting its commendable performance in visible light catalysis and potential for repeated utilization.