ZnO nanoparticles as efficient sunlight driven photocatalyst prepared by solution combustion method involved lime juice as biofuel

[Display omitted] •ZnO nanoparticles synthesised by solution combution method with lemon juice extract.•Samples were characterized by XRD, UV–Vis, PL, FESEM, TEM, XPS, PDS.•Structural and morphological characterizations confirmed the formation of wurzite hexagonal structure.•XPS and PL analysis confirms that the synthesized ZnO will offer effective photocatalytic action.•Exhibits excellent photocatalytic degradation of various organic dyes under UV and sun light (Vis) illumination.•The maximum photocatalytic degradation efficiency was observed about 98.8% for PRA dyes under75 minutes of sunlight irradiation duration. We have prepared high purity Zinc oxide (ZnO) nanoparticles (NPs) by solution combustion synthesis (SCS) method with the aid of lime juice extract. From powder X-ray diffraction (XRD) spectra, it is observed that the ZnO NPs possess single phase, hexagonal wurzite structure with sharp intense peak at (101) plane, agrees with the planes of SAED pattern. Further, the crystallite size is found to be around 18 nm. UV–Vis analysis shows strong UV absorbance band at 381 nm and PL measurements reveals the presence of strong UV emission at 347 nm along with few weak visible emissions. Optical studies infer the existence of lower recombination rate of electron-hole pair, influence the photocatalytic activity of ZnO. From XPS measurements, presence of oxygen rich states on surface are also confirmed (O 1 s states). The degradation performance and reusability of four different dyes (methylene blue (MB), methyl orange (MO), rhodamine B (RhB), Pararosaniline (PRA)) under UV and sunlight irradiations are carried out to illustrate the photo-catalytic activity in presence of a catalyst like ZnO NPs. Comparatively, about 98.8% of PRA and MB dyes are photodegraded at 90 and 75 min of sunlight irradiation, respectively. Among these two, PRA dye shows maximum degradation performance with shorter irradiation time along with good stability, which can be extend very well to minimize the pollution issues happening in society especially, industrial wastes.