Synthesis of Thermoelectric Nanocomposites by Incorporating Reduced Graphene Oxide

Abstract

Thermoelectric energy conversion technology is advancing by leveraging the Seebeck effect to transform waste heat into electricity. Oxide-based thermoelectric materials are particularly attractive due to their excellent figure of merit, chemical and thermal stability, and improved safety compared to chalcogenides. Despite numerous reported high-ZT oxides (ZT>1), maintaining their stability at high temperatures remains a significant challenge. The two-step process here involves blending precursor materials, dissolving them in a solvent, and reacting them to form thermoelectric composites. RGO-doped bismuth titanate nanoparticles were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). We successfully synthesized high-ZT doped n-type and Ag₂Te (p-type) nanostructures via a sol-gel method, achieving uniform microstructures with desirable thermoelectric properties.  Ethylene glycol-based graphene was employed as an eco-friendly reducing agent. The synthesis method for nanomaterials incorporating reduced graphene oxide (RGO) as a dopant demonstrated an impressive Seebeck coefficient (S), a notable figure of merit, high carrier mobility (μ), and a promising power factor. RGO-doped bismuth telluride and Ag₂Te thin films were deposited onto FTO glass substrates via spin coating for p-type and n-type thermoelectric materials. This research revealed a figure of merit around 1.8*10^-4K^-1 within the 800-900 K temperature range.

Received: 28 May 2024 | Revised: 16 July 2024 | Accepted: 20 August 2024

Conflicts of Interest

The authors declare that they have no conflicts of interest to this work.

Data Availability Statement

Data available on request from the corresponding author upon reasonable request.

Author Contribution Statement

Jyoti Bhattacharjee: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing - original draft, Writing - review & editing; Subhasis Roy: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing - original draft, Writing - review & editing, Visualization, Supervision, Project administration.