Optimization of Spikey Gold Nanoparticles and 2D Gold Nanosheets Syntheses

Due to their unique optoelectronic properties, gold nanoparticles (Au NPs) can be used in a variety of applications including electronics, photodynamic therapy, sensors [especially surface enhanced Raman spectroscopy (SERS)], biological probes and imaging, diagnostics, and heterogeneous catalysis. Also, Au NPs can be incorporated into the LiFePO₄ cathode of a lithium ion battery to increase electrical conductivity as they do not alter the crystal structure of the cathode nor readily oxidize¹. This work involves optimizing the anisotropic shape of spikey Au NPs through varying the chemical parameters, such as the reducing agent and colloidal stabilizer or surfactant. Au NPs in 2D shapes, similar to graphene, are intriguing materials for next generation electronics and optoelectronics. Their unique morphology readily allows for incorporation in nanoelectronic devices and layered heterostructures. Using polyvinylpyrrolidone (PVP) as a colloidal stabilizer, ethylene glycol as a reducing agent, and dimethyl sulfoxide (DMSO) as a shape directing agent, micron-sized 2D nanosheets can be selectively synthesized. We optimized a previously-reported synthesis that had many impurity particles to develop an improved version with a higher yield of 2D Au nanosheets.