title: Quantitative nucleation and growth kinetics of gold nanoparticles via model-assisted dynamic spectroscopic approach.
abstract: Lacking of quantitative experimental data and/or kinetic models that could mathematically depict the redox chemistry and the crystallization issue, bottom-to-up formation kinetics of gold nanoparticles (GNPs) remains a challenge. We measured the dynamic regime of GNPs synthesized by l-ascorbic acid (representing a chemical approach) and/or foliar aqueous extract (a biogenic approach) via in situ spectroscopic characterization and established a redox-crystallization model which allows quantitative and separate parameterization of the nucleation and growth processes. The main results were simplified as the following aspects: (I) an efficient approach, i.e., the dynamic in situ spectroscopic characterization assisted with the redox-crystallization model, was established for quantitative analysis of the overall formation kinetics of GNPs in solution; (II) formation of GNPs by the chemical and the biogenic approaches experienced a slow nucleation stage followed by a growth stage which behaved as a mixed-order reaction, and different from the chemical approach, the biogenic method involved heterogeneous nucleation; (III) also, biosynthesis of flaky GNPs was a kinetic-controlled process favored by relatively slow redox chemistry; and (IV) though GNPs formation consists of two aspects, namely the redox chemistry and the crystallization issue, the latter was the rate-determining event that controls the dynamic regime of the whole physicochemical process.
authors.affiliation: Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, National Engineering Laboratory for Green Chemical Productions of Alcohols, Ethers, and Esters, Xiamen University, Xiamen 361005, PR China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Zhou
authors.forename: Huixuan
authors.initials: H
authors.lastname: Wang
authors.forename: Wenshuang
authors.initials: W
authors.lastname: Lin
authors.forename: Liqin
authors.initials: L
authors.lastname: Lin
authors.forename: Yixian
authors.initials: Y
authors.lastname: Gao
authors.forename: Feng
authors.initials: F
authors.lastname: Yang
authors.forename: Mingming
authors.initials: M
authors.lastname: Du
authors.forename: Weiping
authors.initials: W
authors.lastname: Fang
authors.forename: Jiale
authors.initials: J
authors.lastname: Huang
authors.forename: Daohua
authors.initials: D
authors.lastname: Sun
authors.forename: Qingbiao
authors.initials: Q
authors.lastname: Li
mesh_terms: D003460:Crystallization; D006046:Gold / Q000737:chemistry*; D007700:Kinetics; D053768:Metal Nanoparticles / Q000737:chemistry*; D008956:Models, Chemical; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
chemical_list: D006046:Gold
keywords: Crystallization; Gold nanoparticles; Kinetics; Model; Redox