In this work, we studied the carbon quantum dots (CQDs) and functionalized them using phosphorus acid groups and used it as an acid nano-catalyst. The structure and morphology of carbon quantum dots (CQDs) with phosphorous acid tags fully characterized by using various techniques such as Fourier transform infrared (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), fluorescence, thermogravimetric (TG) and X-ray diffraction (XRD) measurements. The final structure of the products was identified using FT-IR and NMR techniques. Among the features of this work are the synthesis of products in green condition, high efficiency, the ability to recover the catalyst several times and short reaction time.
