Optimization of Sodium Tripolyphosphate as a Kinetic Controller in the Nucleation and Growth of CdS Nanoparticles

Authors:
Preprint
Publisher website
Google Scholar
Abstract
Sodium tripolyphosphate has been demonstrated to act as a highly effective kinetic controller in the aqueous synthesis of cadmium sulphide nanoparticles, Redefining its conventional role as a stabilizing agent. By analytically tuning the Sodium tripolyphosphate concentration as 0.5 - 2.5 g, precise control over the nucleation and growth phases was achieved, enabling the formation of cadmium sulphide nanoparticles with a mean diameter of 5.1 nm. High-resolution TEM confirmed excellent crystallinity with lattice spacings of 0.14 nm and 0.15 nm, while XRD revealed a mixed hexagonal cubic phase, with the cubic phase dominating at higher Sodium tripolyphosphate concentrations. UVVis analysis exhibited a tuneable quantum-confined band gap, reached as minimum of 2 eV. XPS measurements verified surface passivation through CdS bond formation and the presence of POCd linkages at 532.1 eV (O 1s), confirming strong coordination between Sodium tripolyphosphate and the CdS surface. Raman spectroscopy further identified the longitudinal optical phonon mode at 148 cm¹ for cadmium sulphide and a symmetric stretching mode at 932 cm¹corresponding to phosphate groups. Collectively, these findings reveal that Sodium tripolyphosphate not only suppresses Ostwald ripening but also modulates crystal phase evolution and surface electronic structure, offering a new kinetic pathway for designing high quality, stable semiconductor nanomaterials through inorganic polyphosphate-assisted synthesis.

This publication has 35 references indexed in Scilit: