Atmospheric pressure non-thermal plasma-liquid interactions for a template-free synthesis of Al-doped CdS nanorods

In this study, Al-doped CdS nanorods were grown via a novel non-thermal plasma-liquid interaction (PLI) at atmospheric pressure. Cd (SO4), Al (NO3)(3) and Na2S2O3 were used as precursors and thioglycolic acid as capping agent. Crystalline structure, morphology and optical properties of nanomaterials have been characterized by means of X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDS), photoluminescence (PL) and UV-vis analyses. XRD patterns showed that as Al incorporates into CdS, the hexagonal phase of CdS developed in new crystalline planes. The FESEM imaging confirmed that one-directional Al-doped CdS nanorods (NRs) were fabricated via PLI method. It was also depicted that NRs size increases simultaneously when plasma treatment time increases till it reaches a diameter and length of 80 and 500 nm, respectively, after 50 min of plasma treatment. EDS analysis demonstrated that Al was introduced in CdS structure successfully via this plasma method. The optimal PL intensity of QD NRs was reached after 40 min synthesis time and Al concentration of 1%. Also as treatment time increases, PL and absorption spectra are red-shifted. The nanostructures indicated a good activity for methyl orange photo-degradation as pollution, in which the activity largely increased after Al-doping. Impedance spectroscopy indicated an enhancement of the electron transport via Al insertion in CdS nanorods.