Optical, bio-sensing, and antibacterial studies on Ni-doped ZnO nanorods, fabricated by chemical co-precipitation method

The wet chemical precipitation method has been used to synthesize Zn1-xNixO (x = 0.0, 0.05, 0.1, 0.15, 0.2) nanorods. The morphological and optical properties of Ni-doped ZnO samples annealed at 500 0C are characterized by X-ray diffraction (XRD), reveals that Ni-doped ZnO crystallites were in hexagonal wurtzite crystal structure with secondary phase (NiO) was detected with a sensitivity of XRD measurement with increasing in the dopant concentration (X = 0.1–0.2). The FTIR spectroscopy furnishes additional evidence on functional groups. The outcome scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results indicated the presence of hexagonal rods like nanostructures. From the BET technique, calculated the pore size distribution and specific surface area of fabricated nanorods. Further, the optical energy bandgap obtained in the series of 3.33–3.11 eV was determined by Kubelka-Munk method. Room temperature photoluminescence (PL) spectra exhibited band edge emission, violet, blue, green, orange, and red emission regardless of the concentration of doping, but intensity increased with levels of Ni2+ ion doping. Cyclic voltammetric (CV) reveals that the Ni incorporation ZnO lattice notably enhanced electrochemical activity with regards to electrochemical sensing of 10 µM uric acid (UA) at a scan rate of 50 mVs−1. Antibacterial studies reveal that the Ni-doped ZnO nanorods possess improved antibacterial activity against both gram-positive (Escherichia coli) and the gram-negative (Enterococcus faecalisis) bacterial strains than the pure ZnO nanorods.