Session: 03-08-01: Computational Modeling and Simulation for Advanced Manufacturing

Paper Number: 150843

150843 - Atomistic Modeling of Thermally-Driven Chemical Processes in Laser Processing of Graphene and Its Oxides 

Two-dimensional materials, such as graphene, have attracted significant interest due to their distinct electronic, optical, thermal, and mechanical properties. However, realizing the practical application of graphene often necessitates tailored manipulation of its nano- or micro-structures. This includes the deliberate introduction of defects, such as nanoholes or oxidation on its basal plane or edges, to tune its properties for specific applications. One widely used method to produce graphene flakes is the thermal reduction of graphene oxide, employing lasers or other thermal techniques. Despite significant efforts to use lasers or microwaves for processing graphene or graphene oxide flakes dispersed in water to fabricate larger-scale structures, the underlying thermal and chemical processes during manufacturing remain poorly understood.

 

In this presentation, we will present our recent investigations utilizing deep neural network potential-based molecular dynamics to study laser-irradiated graphene and graphene oxide flakes in both aqueous and dry environments. We have developed highly accurate deep neural network potentials derived from extensive ab initio molecular dynamics data, incorporating mixtures of graphene, graphene oxide, hydrogen peroxide, water, oxygen, and other relevant species under various thermodynamic conditions. By leveraging this advanced potential, we can rigorously model the heat transfer and chemical reaction processes involving graphene in both wet and dry environments. Specifically, our simulations have provided detailed insights into the unique heat transfer mechanisms between graphene, graphene oxide, and water under laser irradiation or microwave heating. We have observed that the presence of water significantly influences the heat distribution and dissipation, affecting the overall stability and structural integrity of the graphene and graphene oxide flakes. Furthermore, our study has revealed potential chemical reaction processes occurring during these thermal treatments, including the reduction, dehydration, and nanohole creation in graphene oxides, as well as the oxidation of graphene. One key finding of our research is the identification of specific conditions under which the reduction of graphene oxide to graphene can be optimized. For instance, the presence of hydrogen peroxide in the aqueous environment facilitates the removal of oxygen-containing functional groups from the graphene oxide surface, enhancing the reduction efficiency. Additionally, our simulations have shown that the laser or microwave-induced heat can promote the formation of nanoholes, which can be beneficial for certain applications requiring porous graphene structures.

 

Our research holds promise in offering valuable insights for the design and optimization of laser or microwave-based manufacturing processes for two-dimensional materials in wet environments. By understanding the intricate interplay between heat transfer and chemical reactions, we can better control the structural and chemical properties of graphene and graphene oxide during production. This knowledge paves the way for developing more efficient and scalable methods to produce high-quality graphene-based materials for various technological applications, including electronics, photonics, and energy storage.

 

In conclusion, our work highlights the importance of combining advanced molecular dynamics simulations with deep neural network potentials to unravel the complex thermal and chemical processes involved in the laser or microwave processing of graphene and graphene oxide. These findings contribute to the broader effort of translating the remarkable properties of two-dimensional materials into practical applications, ultimately advancing the field of nanomaterials and their integration into next-generation technologies.

Presenting Author: Haoran Cui University of Nevada, Reno

Presenting Author Biography: Haoran Cui is a 4th year Ph.D student in the University of Nevada, Reno.

Authors:

Haoran Cui University of Nevada, Reno
Yan Wang University of Nevada, Reno