The use of phthalocyanines@g-C3N4 nanosheets conjugates supported on TiO2 fibers for photosono-catalytic degradation of rhodamine 6G

In this study, four differently substituted phthalocyanines (named as 1,2,3 and 4) were conjugated to graphitic carbon nitride nanosheets and used to functionalize TiO2 fibers (to form 1@g-C3N4-TiO2 fibers, 2@g-C3N4-TiO2 fibers, 3@g-C3N4-TiO2 fibers and 4@g-C3N4-TiO2 fibers) for ultrasound and visible light (photosono-catalysis) initiated degradation of Rhodamine 6G are reported. The catalysts were characterized with microscopic and spectroscopic techniques. All the functionalized fibers obtained 100 % efficiency toward Rhodamine 6G degradation for photosono-catalysis. 4@g-C3N4-TiO2 fibers showed higher catalytic efficiency than all the catalysts, which was confirmed by higher rate constant. The electron paramagnetic resonance (EPR) and trapping agents showed that photo-catalytic process is initiated by singlet oxygen (O-1(2)) and whereas sono- and photosonocatalytic processes were initiated by singlet oxygen (O-1(2)) and hydroxide radicals (center dot OH). The high efficiency and affordability of the process makes it a potential prospect to be used in removal of organic pollutants in wastewater.