Colloidal metal nanocatalysts to advance orange II hydrogenolysis tracked by a microplate reader

The thermal reduction method was applied to synthesize metal nanoparticles using poly(1-vinyl-2-pyrrolidone) as an organic stabilizer to control metal nanoparticle agglomeration. Colloidal metal nanoparticles, gold, palladium, and gold-palladium nanoparticles were synthesized, and UV-visible spectrophotometry and high-resolution transmission electron microscopy analyses were conducted to characterize them. The metal nanoparticle micrographs showed well-dispersed particles with an average size of 9.6 nm (Au), 15.4 nm (Pd), and 10.6 nm (AuPd). All the colloidal metal nanoparticles served as nanocatalysts to advance a reductive degradation of orange II in presence of borohydride ions. For a prompt screening of catalytic activity, the microplate reader system was considered at a fixed maximum absorbance wavelength of lambda 489 nm respected by orange II. Excess borohydride ions were used to construct pseudo-first kinetic conditions. The Langmuir-Hinshelwood model allowed the finding of kinetic activity on the surface of metal nanoparticles. AuPd nanocatalyst interface exhibited low activation energy (5.38 kJ -mol(-1)) compared to the one on Au (8.19 kJ -mol(-1)) and Pd (7.23 kJ -mol(-1)). [Graphics] .

Automated summary

The thermal reduction method was used to synthesize metal nanoparticles with poly(1-vinyl-2-pyrrolidone) as an organic stabilizer. The synthesized colloidal metal nanoparticles, including gold, palladium, and gold-palladium nanoparticles, were characterized by UV-visible spectrophotometry and high-resolution transmission electron microscopy. All of these metal nanoparticles exhibited catalytic activity in the reductive degradation of orange II in the presence of borohydride ions. The kinetic activity on the surface of the AuPd nanocatalyst interface was found to be lower than that of Au and Pd.