Nitrogen doped carbon quantum dots and GO modified WO3 nanosheets combination as an effective visible photo catalyst

[Display omitted] •Nitrogen doped carbon quantum dots based highly efficient ternary photo catalyst are fabricated by facile route of wet chemical method.•The surface of WO3 nano sheets is modified with morphological defects making more active sites available.•NCQDs modified ternary photo catalyst confirmed the efficient charge separation to suppress the electron/hole pair recombination.•This enhanced photocatalytic activity of NCQDs is attributed to the availability of active sites for carrying of charges.•The amphiphilic nature of GO sheets reduces the tension among WO3 floral nano-sheets making the surface rough and distorted.•Ternary WO3/GO/NCQDs nanocomposite is highly stable.•By introduction of nitrogen doped CQDs into the system recovers the sheet like structure with increased transparency. Nitrogen doped carbon quantum dots (NCQDs) based highly efficient ternary photocatalyst are fabricated by modifying surface of GO incorporated WO3 nano-sheets. XRD confirmed the formation of monoclinicWO3 nano-sheets. All the characteristic peaks of WO3, GO and NCQDs are obvious in XRD patterns of WO3/GO/NCQDs ternary photocatalysts confirming successful fabrication of the photocatalysts. SEM images showed that WO3 host matrix is distorted after incorporation of GO and NCQDs owing to lower interfacial tension. The surface of WO3 nano-sheets is modified with morphological defects making more active sites available. UV–vis spectra exhibited extended visible light absorption and remarkable reduction of WO3 band gap energy. The photoluminescence spectra confirmed the efficient charge separation in NCQDs modified ternary photocatalyst. The synthesized composites were applied for the photocatalytic degradation of harmful organic dye i.e. methyl orange (MO). The ternary composites represented the excellent photocatalytic activity as compared to binary and pure WO3 photocatalysts. This enhanced photocatalytic activity is attributed to the availability of active sites, extended light absorption in visible region and enhanced charge separation efficiency.