Optical and thermal response of single-walled carbon nanotube–copper sulfide nanoparticle hybrid nanomaterials

Abstract

This paper reports the optical and thermal response of a single-walled carbon nanotube-copper sulfide nanoparticle (SWNT-CuS NP) hybrid nanomaterial and its application as a thermoelectric generator. The hybrid nanomaterial was synthesized using oleylamine molecules as the linker molecules between SWNTs and CuS NPs. Measurements found that the hybrid nanomaterial has significantly increased light absorption (up to 80%) compared to the pure SWNT. Measurements also found that the hybrid nanomaterial thin-film devices exhibit a clear optical and thermal switching effect, which can be further enhanced up to 10 × by asymmetric illumination of light and thermal radiation on the thin-film devices instead of symmetric illumination. A simple prototype thermoelectric generator enabled by the hybrid nanomaterials is demonstrated, indicating a new route for achieving thermoelectricity.

A fluidic microenergy generator enabled by hybrid nanomaterial nanofluids

“…As the concentrations of nanofluids increase, more SWNT-CuS NPs hybrid nanomaterials are dispersed into water (base fluid). Due to the dispersed nanomaterials in nanofluids, the total light absorbance by nanofluids is increased not only due to the direct capture of photons from the light source by the SWNTs and CuS NPs [8][9], but also due to the scattering of light by SWNTs and CuS NPs [2]. Specifically, as shown in Fig.…”

“…When the nanofluids are pumped into the fluidic chamber, the magnitude of the output voltage suddenly jumps up since the temperature at the Si-Cu junction attached to the fluidic chamber falls down due to the nanofluids, whose temperature is lower than the room temperature. As the nanofluids begin to absorb light, temperature at the Si-Cu junction increases due to the heat converted by the SWNT-CuS NPs hybrid nanomaterials in the nanofluids [9], and the temperature of this junction becomes higher than room temperature. As a result, the output voltage quickly changes from negative to positive, then gradually increases.…”

“…The following equation describes the voltage generated by the microenergy generator due to the Seebeck effect [7,9]:…”

“…Compared to SWNT [7], the SWNT-based hybrid nanomaterial shows improved capability for optical and thermal absorption [8][9]. Hence, it is anticipated that hybrid nanomaterial-based nanofluids could enhance the absorption and storage of solar and thermal energy significantly.…”

Hybrid nanomaterial-based nanofluids for micropower generation

“…The temperature difference between the two Si-Cu junctions (J1 and J2) is therefore formed, resulting in the power generation due to the different Seebeck coefficients of Si and Cu based on the thermoelectric mechanism. [8][9][10] Experimental methods…”