Green hydroelectrical energy source based on water dissociation by nanoporous ferrite

Abstract

Summary Dissociation of water molecule occurs on octahedrally coordinated unsaturated suface cations and oxygen vacancies created by lithium substitution in magnesium ferrite. Lower synthesis temperature of ferrite has generated nanopores in microstructure. Dissociated hydronium and hydroxyl ions are transported through surface and capillary diffusion in porous ferrite network towards attached Zn and Ag electrodes. Water molecule dissociation ability of nanoporous ferrite has been exploited to develop a green electrical energy cell, which is a combination of material science and electrode chemistry. The innovated cell has been nomenclatured as hydroelectric cell (HEC). When HEC is partially dipped in deionized water, spontaneously hydroxide and hydronium ions are produced by water molecule dissociation. Hydronium ions trapped in nanopores develop enough electric field that further dissociates physisorbed water molecules. Thereby, the process of water molecule dissociation is accelerated in a bigger way to increase ionic current in the cell. Oxidation of Zn electrode by hydroxide ion and reduction of H3O+ at Ag electrode develop voltage and electric current in the cell. The HEC cell of a 17 cm2 area is able to generate a short circuit current of 82 mA and 920 mV emf with a maximum output power of 74 mW, which is three order higher than reported output power 1.4 μW/cm2 produced by water in cement matrix. Hydroelectric cell performance is repetitive, stable and possesses potential to replace traditional ways of generating renewable energy in terms of cost and safety. Copyright © 2016 John Wiley & Sons, Ltd.

Harvesting energy via stimuli‐free water/moisture dissociation by mesoporous SnO 2 –based hydroelectric cell and CuO as a pump for atmospheric moisture

“…The absorption spectrum shown in Figure 1D reveals a sharp absorption edge at~340 nm related to the direct band edge transition of SnO 2 . 18,25,26 Here, the strong electrostatic field, generated due to presence of oxygen vacancies 27,28 (existence of oxygen vacancies were confirmed with photoluminescence spectra shown in Figure S1), dissociates the water molecules (as seen in Figure 2B) according to Tauc plot, as shown in the inset of Figure 1D, confirms a direct bandgap of~3.62 eV and is in accordance with earlier report.…”

“…34,35 When the CuO is kept at 25°C with 76% RH, the color of the sample changes from dark black (0 minutes) to light green in 60 to 70 minutes ( Figure 4A(iii)). 26,27 Figure 4B(ii) shows that the mesoporous SnO 2 -based hydroelectric cell can generate the potential in the presence of the moisture absorbing layer of CuO. The structural analysis before (red curve in Figure 4A(iii)) and after (blue curve in Figure 4A(iii)) moisture absorption confirms the Cu (OH) 2 complex formation.…”

“…41-0254. [26][27][28] As discussed above, OHoxidized the Al electrode to release the 3e in the system to develop the potential via subsequent H 2 evolution. The presence of small amount of Cl helps the CuO to slowly react with the atmospheric moisture, which latter getting pumped to porous SnO 2, which leads to the formation of Cu (OH) 2 complex.…”

“…27 The generated OHreact with the Al electrode (Al foil used here) as The positively charged hydronium ions generate additional high enough electric field inside the pore which further helps to dissociate the physisorbed water molecules spontaneously.…”

Significance of interface barrier at electrode of hematite hydroelectric cell for generating ecopower by water splitting

“…Novel green energy device hydroelectric cell has been originated as a potential candidate to play pivotal role in this direction without using any solar/UV irradiation/electrolyte, while it uses little water for energy generation . Water molecule dissociates on octahedrally undercoordinated cations and oxygen defects in nanoporous lithium‐substituted magnesium ferrite .…”