Biosynthesis and characterization of carbon quantum Dots@CuS composite using water hyacinth leaves and its usage in photocatalytic dilapidation of Brilliant Green dye

The investigation on the degradation of water-soluble dye Brilliant green was done by using CQDs@CuS. Water-dissolvable, green incandescent CQDs (carbon quantum dots) were fabricated with a high yield by carbonization of water hyacinth (Eichhornia crassipes) weed for the first time at a mild temperature without using any surface activating reagents or salt. The sol-gel method was utilized for the fabrication of copper sulfide (CuS) nanoparticles. An attempt was made to synthesize a composite of CuS NPs with CQDs. The structural and composition determination of synthesized CuS, CQD, and composite (CQDs/CuS) was done by HRTEM, FESEM, XRD, XPS, FTIR, BET, and EDS techniques. TEM and XRD studies are congruent with the amorphous and hexagonal structure of CQDs and CuS, respectively. Various quality parameters such as DO (dissolved oxygen), COD (chemical oxygen demand), conductivity, salinity, and TDS (total dissolved solids) have been measured to observe the extent of degradation of dye. The comparative study has proven that composite (CQDs/CuS) have shown the greatest photocatalytic action for the dilapidation of Brilliant green than CuS NPs only. The probable trail of the dilapidation of dye has also been suggested. [Display omitted] •CQDs were prepared by Water hyacinth.•Prepared CQDs were composited with CuS for the removal of pollutants.•Green routes were employed.•BG is degraded completely using the prepared composite.•A sustainable way of removal of pollutants by the use of weed.