Flexible Hybridized Nanogenerators Based on a Reduced Graphene Oxide Nanosheet-Decorated Piezoceramic Skeleton to Impact Mechanical and Thermal Energy Harvesting

Abstract

Flexible hybridized nanogenerators (FHNGs) with multifunctional piezocomposites as core can simultaneously harvest waste mechanical energy and thermal energy in the environment, which are expected to replace chemical batteries to realize a long-term self-power supply of wearable electronic devices. However, most reported piezocomposites filled with low-dimensional ferroelectric particles have low piezoelectric charge coefficients together with poor thermal conductivity, which are not conducive to improving the hybridized generation power. In this work, an effective design strategy with respect to a reduced graphene oxide (rGO) nanosheet-decorated three-dimensional (3-D) samarium-doped Pb(Mg 1/3 Nb 2/3 )O 3 −PbTiO 3 (Sm-PMN-PT) piezoceramic skeleton is proposed to build high-performance polydimethylsiloxane (PDMS)based FHNGs. On the one hand, rGO nanosheets with high electrical conductivity can form an internal electric field network to assist artificial polarization of the piezoceramic skeleton to enhance the piezoelectric properties. On the other hand, rGO nanosheets with high thermal conductivity can form a heat-transfer network to increase the rate of temperature change over time and improve the pyroelectric properties. Thanks to the coupling enhancement effect associated with rGO nanosheets, highly efficient concurrent mechanical energy harvesting (∼0.53 V), and thermal energy harvesting (∼0.151 V) were realized in the Sm-PMN-PT/PDMS/rGO piezocomposite, and the total output voltage of the FHNG under hybrid excitation was as high as 0.705 V, providing a promising paradigm for the development of high-performance FHNG materials.

Triggering Redox Active Sites Through Electronic Structure Modulation in rGO Encapsulated Mixed Transition Metal Oxides Hybrid for Alkaline Hydrogen Evolution

“…This can be achieved by the addition of various nanoparticles to rGO. Thus, the novel rGO hybrids, achieved through hybridization of rGO with nanoparticles, have gained substantial attraction for their catalytic, magnetic, and optoelectronic attributes . The distinctive sp 2 hybridization in graphene allows excellent electronic conduction by promoting electron delocalization.…”