pH Dependence on the Synthesis of Gold Nanoparticles Capped Na-Citrate from Adsorbed Au(III) and Au(0) on Salicylic Acid Immobilized Mg/Al Hydrotalcite

Abstract

The investigation of pH dependence on the synthesis of gold nanoparticles capped Na-citrate from adsorbed Au(III) and Au(0) on salicylic acid immobilized hydotalcite had been carried out under ultrasound irradiation. Evidenced by UV-visible spectrophotometer, pH 3.0 revealed to be the optimum condition where gold nanoparticles show the evidence of surface plasmon resonance (SPR) at 547 nm. The deprotonation of 1-and 2-carboxylic groups of capping agent citrate was lead to the forming of [C6H6O7] 2-which acts as both reduction and desorption agents of Au(III) and Au(0), respectively. Characterization using X-ray diffraction and transmission electron microscopy supported the successful synthesis of gold nanoparticles by the appearance of gold lattice index (111; 200; 220 and 311) and 2D nanoparticles image with the average size of 84.72 nm.

Immobilization of Salicylic Acid on Ni-Zn Layered Hydroxide Salts

“…It is also shown here that the neutral pH was favorable for the immobilization of the acid. This outcome of salicylate adsorption behavior is in substantial agreement with those in the report of immobilized salicylic acid Mg/Al hydrotalcite [7,8]. XRD and IR characterization.…”

“…The first band is attributed to the bending mode of C-O in the phenolate group while the second one is assigned to the asymmetric stretching mode of C-H (sp 2 ) groups. These results were confirmed by the literature [7,8].…”