Habib G.Ranjbar personal website - Nanomaterials synthesis and characterization

Synthesis of nanoparticles

Nanomaterials have been the focus of research during the last decades due to their high surface area and exceptional physicochemical properties leveraging advances in materials science and synthesis. The synthesis and design of nanomaterials with desired properties for a particular application is the main focus of nanotechnology. I have been synthesized and characterized various types of nanomaterials including semiconducting nanoparticles, conductive polymers, and graphene nanocomposites for wastewater treatment and energy storage applications. Particularly, I have designed materials that remove organic pollutants from wastewater under sunlight as well as materials for supercapacitors with improved capacitance and cycle life.

Below are the SEM images of some of the nanoparticles that I have synthesized.

Solid-state materials characterization

For materials to be effectively utilized in applications such as sensors, electronics, energy storage and conversion systems it's necessary to be immobilized on a surface and evaluate their performance in solid-state. I have prepared different types of self-assembled monolayers (SAMs) grown on a gold surface and deposit molecular clusters onto SAMs and evaluate their structure and property with different solid-state characterization methods including uv/vis and infrared reflection absorption spectroscopy (IR-RAS and UV/VIS-RAS), X-ray absorption spectroscopy (XAS), powder X-ray (PXRD), scanning electron microscopy coupled with energy dispersive x-ray (SEM-EDX), as well as superconducting quantum interference device (SQUID) for magnetic characterizations. The combination of these characterizations provides a clear chemical, electronic, and structural insight into prepared materials.

In an effort towards functionalization of the surface of Co6S8(PEt3)6+ with a reactive carbonyl ligand, CO, I substituted PEt3 ligand with CO and soft-landed Co6S8(PEt3)5CO+ onto a SAM surface. IRRAS spectrum of soft-landed Co6S8(PEt3)5CO+ exhibits a strong peak at 1978cm-1. Successful soft-landing of Co6S8(PEt3)5CO+ gives us the freedom to conduct reactive landing and directly graft the cluster to a carefully selected SAM surface.

I have prepared highly ordered vertically aligned TiO2 nanotubes through anodization method and soft-landed W-polyoxomethalate,[PW12O40]3-, to see how far WPOM3- penetrates inside the 10 um nanotubes. The EDX line scan across the nanotube showed that the soft-landed WPOM3- only penetrates to the top 1.3 um of the nanotubes.