Synergistic nanomaterial system for luminescence sensing of MnO4- anion and enhanced photocatalytic removal of antibiotic chloramphenicol (CAP) in aqueous environments using Dy3+/Tb3+ co-doped NaYF4 and graphene oxide hybrid

The presence of industrial pollutants in water bodies, particularly metal anions and organic pollutants, has put human health and the environment at risk worldwide, triggering the research and development of multifunctional nanoparticles that not only have excellent luminescence detection ability but also possess simultaneous photo-degradation activity against harmful pollutants. Herein, we have synthesized Dy3+/Tb3+ co-doped NaYF4 (Tb-NP) and (Tb-GO) NaYF4:Dy3+/Tb3+@GO(GO=Graphene oxide) nano hybrids via hydrothermal approach and tested their functional activity for the fluorescence selective detection of MnO4- anions and photocatalytic degradation of drug Chloramphenicol (CAP) in aqueous medium. The physicochemical characterization of prepared nanosamples was examined utilizing variety of analytical methods. The luminescent property of NaYF4:Dy3+/Tb3+(7%) revealed that it is exceptionally sensitive and selective towards the detection ofMnO4- anion in aqueous medium. It was observed that, when varied amount of MnO4- anion was added to a suspension solution containing the synthesized NaYF4:Dy3+/Tb3+(7%) chemosensor, the photoluminescence emission band at 545 nm was significantly quenched. Moreover, NaYF4:Dy3+/Tb3+(Tb-NP) exhibited the limit of detection (LOD)value of 0.65 ppm along with high Stern-Volmer (Ksv) quenching constant value of 4.75 ×105 M-1 for MnO4- anion, indicating great selectivity and sensitivity of the designed nanosensors towards MnO4- anion. Further, the Graphene oxide (GO) conjoined NaYF4:Dy3+/Tb3+(7%) nanohybrid showed accelerating photocatalytic activity toward the degradation of CAP in aqueous medium under UV-irradiation. The obtained results of UV-Vis spectroscopy clearly indicate that NaYF4:Dy3+/Tb3+@GO (Tb/GO) nanohybrid can act as a superior nanocatalyst than that of NaYF4:Dy3+/Tb3+(Tb-NP) nanophosphors. The photocatalytic efficiency of NaYF4:Dy3+/Tb3+@GO (Tb/GO) nanohybrid toward degradation of CAP is around 95.6% within 50 minutes under UV light and it maintains remarkable stability even after five repeated catalytic cycles. In conclusion, this study presents a feasible method for immediate detection of MnO4- anion and improved photo-catalytic degradation of CAP in an aqueous medium employing NaYF4:Dy3+/Tb3+(Tb-NP) and NaYF4:Dy3+/Tb3+@GO (Tb/GO) as dual functional nanomaterials.