Plasmonic materials have been widely used for many applications such as photothermal therapy, chemical and biological sensing, and solar cells. Most common plasmonic nanomaterials consist of noble metals, gold and silver. However, these materials are expensive and hinder applications that require scaling up. Furthermore, gold and silver nanoparticles are susceptible to sintering when used as solar concentrators. As an alternative to noble metals, metal nitrides have been proposed to have plasmonic properties according to theoretical investigations. Metal nitrides are relatively inexpensive, possess high temperature stability, chemical stability, and mechanical hardness. However, these metal nitrides have not been experimentally investigated thoroughly. This poster will highlight successful synthesis of group 4 (Ti, Zr, and Hf) nitride nanoparticles using a solid-state metathesis reaction which yielded plasmonic nanoparticles that were dispersible in water. These metal nitride nanocrystals had localized surface plasmonic resonance in the near-infrared region for TiN and in the visible region for ZrN and HfN. Photothermal properties of group 4 nitride nanoparticles were compared to gold nanorods benchmark under 1.0 W cm<sup>-2</sup> illumination at 850 nm. HfN exhibited the highest photothermal transduction efficiency of 65%, followed by ZrN (58%), and TiN (49%) which were all higher than gold nanorods (43%). Based on the FEM model, HfN had the lowest scattering cross-section which maximized the light-to-heat conversion, whereas gold nanorods had the largest scattering cross-section that resulted in the lowest photothermal transduction efficiency. Along with the high photothermal transduction efficiencies, these materials exhibited photothermal stability over five cycles of continuous excitation which could be promising for many applications.

Synthesis and photothermal properties of plasmonic group 4 nitride nanocrystals

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.