Hierarchical Reduced Graphene Oxide Film as an Efficient Large-Area Solar Thermal Absorber
International Conference on Advadced Materials and Devices, Jeju, Korea(2023)
Dongpyo Hong, Ye Rim Kim, Seo Young Kang, Yong Joon Lee, Jae Yeon Won, Jun Yong Song, In-Sung Lee, In Gyun Jung, Ji-ni Kim, Young Joon Yoo, Sang Yoon Park
Abstract
As the demand for clean and sustainable energy sources continues to rise, solar energy conversion technology plays a pivotal role in meeting these needs. Solar absorbers serve as the foundational materials for diverse applications, ranging from solar-thermal power generation to household water heaters and water purification systems.
In this study, we introduce an innovative approach to create a highly efficient large-area solar absorber by employing an ultrafast self-expansion and reduction (USER) process on graphene oxide. The resulting material, termed Hierarchical Reduced Graphene Oxide Film (HrGOF), exhibits remarkable solar absorbance properties, reaching up to 99%. Under one sun irradiation, the HrGOF was observed to elevate temperatures to 70 degrees Celsius.
The morphology and optical characteristics of the HrGOF are found to be intricately linked to the sheet size and chemical structure of the graphene oxide prior to reduction, particularly the presence of unexfoliated graphite oxide particles. The initial state of the graphene oxide film significantly influences the gas escape dynamics during the formation of HrGOF. The exceptional light absorption properties observed in the optimized HrGOF structure result from impedance matching and the interplay of multiple reflections within the material.
This research represents a significant advancement in the development of efficient solar thermal absorbers, with the potential to revolutionize various solar energy applications. The insights gained from this study provide a foundation for further optimizing solar absorber materials and advancing the field of solar energy conversion technology.