Hanani Yazid, Abdul Mutalib Md Jani, Farah Wahida Ahmad Zulkifli, Najwa Afifi Abdul Wahab and Najatin Syahirah Ahmad Sabri.
Keywords: Gold nanoparticles, Carbon nanotubes, Metal oxides, Polymers, p-nitrophenol
Abstract: Gold nanoparticles (Au NPs) on various support materials such as carbon nanotubes (CNTs), metal oxides (MOs), and polymers were successfully prepared by deposition-precipitation method (DP). Supported Au NPs were synthesized in two different platforms which are in the form of powder and thin film. The Au NPs are in form of powder when CNTs as support. While supports such as polymeric materials including polyethylene (PE), and polydimethylsiloxane (PDMS), as well as some porous materials such as anodized aluminium oxide (AAO) and titania oxide (TiO2) membrane produce Au NPs catalyst in form on thin film. The supported Au NPs catalyst also was improvised by the hybridization of Au NPs on bi-supported material such as CNTs/AAO. Collectively, it was found that the method of preparation was successful and the formation of Au NPs were characterized by Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscope (FESEM). All the prepared Au supported catalysts were tested in the of reduction p-nitrophenol (p-NP) to p-aminophenol (p-AP). The catalytic reaction was carried out at room temperature and atmospheric pressure in an excess sodium borohydride (NaBH4) and monitored by UV-Vis spectrophotometer. It was found that bi-supported Au catalysts show an excellent catalytic performance up to 10-2 s-1 of rate constant, which was higher in one order of magnitude compared to conventional catalyst for reduction of p-NP. Besides, this Au-CNTs/AAO catalyst was in form of thin film which facilitated the removal of catalyst from liquid-phase reaction medium, thus improved the reusability of the catalyst.