The interaction of sodium mercaptobenzothiazole with gold electrode and nanorod surfaces

Attenuated total reflectance Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy have been applied to characterise and investigate the interaction of sodium mercaptobenzothiazole (MBT) with gold surfaces and gold nanorods. Gold nanorods (Au NRs) with average aspect ratio of 4.04 ± 0.08 were synthesised and reacted with MBT. Gold(I) mercaptobenzothiazole and the dithiolate, 2,2′-dithiobisbenzothiazole ((MBT)₂) were synthesised and characterised to provide a basis for compound identification. It was concluded that MBT could link two Au NRs by adsorption through the exocyclic S atom on one NR and the endocyclic S atom on the other NR, thereby leading to the formation of Au nanochains in the suspension. The MBT flotation of 100 μm gold particles was also investigated utilising controlled potential techniques. The gold metal particles floated in the cell when the potential reached 0.5 V. At that potential, (MBT)₂ was observed on the gold particles, and their floatability was attributed to the adsorption of that dithiolate species.