Synthesis of multi-walled phosphorus and sulfur co-doped CNTs
Phosphorous and sulfur co-doped carbon nanotubes (PSCNTs) has prepared from the catalytic chemical vapor deposition (CVD) method, starting from available materials and cheap catalyst. Triphenyl phosphine and sulfur were applied in first zone and the catalyst applied in second zone to prepare the product from acetylene gas at 720 °C. The structure of product was confirmed using field emission scanning electron microscopy (FESEM) and the presence of phosphorous and sulfur atoms was defined using energy-dispersive X-ray spectroscopy (EDS) method. Thermal behavior of the prepared PSCNT was analyzed from thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in 25–890 °C, showing total 25% weight loss. Moreover, XRD patterns and Raman spectrum were obtained to define more properties of the product. Finally, the electrocatalytic ability of the prepared PSCNT in oxygen reduction reaction (ORR) was analyzed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) diagrams. The obtained diagrams showed appropriate catalytic activity in the ORR region.