Enhancing the Thermoelectric Properties of Graphene Oxide throughModification with Polyhedral Oligomeric Silsesquioxane (POSS):Synthesis, Reduction, and Optimization

Thermoelectric materials hold great promise for energy conversion applications, offering directconversion of heat into electricity. Their performance is dictated by key parameters includingelectrical conductivity, Seebeck coefficient, and thermal conductivity. This study focuses onenhancing the thermoelectric properties (increasing seebeck coefficient and reducing thermalconductivity) of reduced graphene oxide (rGO) through modification with Polyhedral OligomericSilsesquioxane (POSS) nanoparticles. Graphene oxide nanoparticles were synthesized andsubsequently modified by using various types of amino-functionalized POSS nanoparticles througha rapid process and then reducing via a chemical reduction agent. The POSS nanoparticles reducedthermal conductivity through enhanced phonon scattering due to the cage-like structure of POSS. Themodifications also led to an increase in the Seebeck coefficient by altering the Fermi levels and bandgaps and energy filtration. The reduction process and formation of POSS-GO composites resulted ina boosted power factor and reduced thermal conductivity. Optimized POSS-GO composite exhibited۳۲-fold increase in thermoelectric efficiency, ZT, compared to unmodified rGO. Enhancedthermoelectric performance can be also attributed to creation of additional carrier transport channelswhen modified with phenyl-containing POSS. The heterointerface between GO and POSS played apivotal role, facilitating improved electron-hole separation and efficient charge transport. This studyunderscores the potential of POSS nanoparticles in augmenting the thermoelectric properties ofgraphene oxide. Findings offer crucial insights into design and optimization of high-performancethermoelectric materials through strategic modifications.

کلیدواژه ها:

Thermoelectric ، Reduced Graphene oxide ، POSS ، Thermal conductivity