Output density quantification of electricity generation by flowing deionized water on graphene

Abstract

Energy conversion by water flowing over graphene is a promising mode of energy harvesting. However, the mechanism, energy-conversion efficiency, and quantification of power density for this mode of interfacial electricity generation remain unknown. Quantification of the output performance for the flow-induced electricity generation using graphene is presented in this work. The output performance per unit contact area between water and graphene is found to be proportional to the flow speed, with an electromotive force density of 0.0025 [μV/mm2/mm/s] for the conditions used in this work. The ability to quantify output density will help to construct guidelines for future applications of this form of electricity generation.

Strong electronic winds blowing under liquid flows on carbon surfaces

“…While our results echo previous reports of electric potential differences induced by water flow in carbon-based nanomaterials [3][4][5][6][7][8][9][10][11][12][13][14], our nanoscale investigation puts us in position to disentangle various effects at the root of electronic current generation under fluid flow, and get much insights into the molecular mechanism underlying the phenomenon. Previously, sev-eral mechanisms have been invoked to rationalize such conversion, including streaming potential effects [5], adsorbed/desorbed ion hopping [6,9], Coulomb drag [4,8] or charging/discharging of a pseudo-capacitance [13,14].…”

“…However, while the structural properties and chemistry of interfaces have been intensively explored, the effect of the solid-state electronic transport at the fluid interface has been broadly overlooked up to now. It has been reported that water flowing against carbon-based nanomaterials, such as carbon nanotubes [3][4][5][6][7][8] or graphene sheets [9][10][11][12][13][14], does induce electronic currents, but the mechanism at stake remains controversial [9,10,15]. Here, we unveil the molecular mechanisms underlying the hydro-electronic couplings by investigating the electronic conversion under flow at the nanoscale.…”

“…However, recent results for fluid and ion transport in carbon nanotubes and nanochannels made of graphitic materials have pointed out the limits of such standard description for fluid-solid interactions and existing couplings of liquid transport with electronic degrees of freedom inside the confining walls. This takes the form of electronic currents induced in the solid surface under flowing † These authors contributed equally to this work liquid [4,5,[7][8][9][10][11][12][13][14], the modification of wetting by electronic screening [16,17], or anomalies in the water-carbon friction [18]. The interaction mechanisms at stake remain largely unexplained and to be properly understood.…”

Synthesis of borophene on quartz towards hydroelectric generators

“…20 Various nanomaterials such as graphene, carbon nanotubes and silicon nanowires have been extensively investigated to harvest the water energy to transform electricity. [23][24][25][26][27][28][29][30][31] To improve the efficiency of energy transfer, the use of novel nanomaterials to capture electricity is always a research direction for continuous exploration. 32 Borophene has a distinctive electronic structure that makes it possible easy charge transfer between it and ions or molecules.…”

Graphene-Based Assemblies for Moist-Electric Generation

“…Specifically, he created an electric voltage by flowing electrolytes through a narrow channel under a pressure gradient (van der Heyden et al, 2005). Since then, many studies have confirmed that electricity may be generated directly in nanomaterials, including carbon nanoparticles, carbon nanotubes, polymer materials, graphene, and nanostructured silicon, under the effects of water flow, waves, and water evaporation (Zhao et al, 2008;Fei et al, 2019;Zhang et al, 2019;Qin et al, 2020a;Kuriya et al, 2020;Zhou et al, 2020). Based on this principle, Wang et al (Wang et al, 2021) have designed and developed a heterogeneous moisture-enabled electric generator that can yield voltages greater than 1,000 V under ambient conditions (25% relative humidity (RH), 25 °C).…”