Tuning the structural, morphological, optical, wetting properties and anti-fungal activity of ZnO nanoparticles by C doping

Sol–gel (SG) and direct precipitation (DP) routes were used to synthesize zinc oxide (ZnO) nanoparticles. C-doping (1At.% and 2At.%) in ZnO nanoparticles was performed by precipitation method (PM) and C doping (10% and 20%) was performed by thermal deposition (TD) method. The structural, morphological, optical, wetting properties and antifungal activity of the undoped and doped nanoparticles were studied. X-ray diffraction (XRD) revealed the hexagonal wurtzite crystalline phase for SG and DP derived nanoparticles. The C-doping of ZnO revealed that there is no transition in crystallinity and phase of ZnO nanostructure. The crystallinity and phase remain the same even after doping of carbon atoms. The XRD results show that the peaks of pure and C-doped ZnO nanoparticles are present in the same phase. Field-emission scanning electron microscopy (FESEM) revealed the morphology of undoped and doped ZnO nanoparticles. Almost spherical nanoparticles were revealed for SG and DP derived pure ZnO nanoparticles. The C-doped ZnO nanoparticles revealed spherical and hexagonal-rod shaped nanoparticles for PM and TD derived nanoparticles, respectively. The doped ZnO showed the increased band gap compared to the band gap of the pure ZnO nanoparticles. Photoluminescence (PL) spectroscopy was performed to find out the optical properties. The hydrophilic nature of DP and SG derived ZnO nanoparticles changed to the hydrophobic nature owing to C doping which is attributed to the variation in the roughness of the doped nanostructures. The doped ZnO nanostructures revealed better resistance to the growth of the ‘Rhizopus Stolonifer’ fungus compared to the undoped ZnO nanoparticles.