Highly Accelerated, Sustainable, Abundant Water Splitting at Room Temperature Generating Green Electricity by Sb-Doped SnO₂ Hydroelectric Cell

Abstract

Hydroelectric cell (HEC), a revolutionary invention, has created a new exclusive domain in green energy generation by defect-assisted water splitting/dissociation on metal oxides. In the present work, doping of metallic antimony (Sb) in tin oxide (SnO 2 ) abundantly produced oxygen vacancies. It significantly increased the active centers for adsorption and dissociation of water that ultimately led to highly accelerated water splitting to generate a record high current in a Sb−SnO 2based HEC. The photoluminescence (PL) emission peak at 656 nm confirms the electronic transitions to defect levels generated by tin (Sn) interstitials. Raman spectroscopy showed enhanced inplane oxygen vacancies with the presence of the prominent broadening of the 571 cm −1 mode. The X-ray photoemission spectroscopy (XPS) results suggest that a large amount of antimony is segregated on the surface and grain boundaries in the 3+ oxidation state. A large number of defect pair Sb 3+ −V o ** centers accompanied by a highly reduced surface due to Sb led to 4-fold current production by the HEC based on Sb−SnO 2 compared to SnO 2 . The g values calculated from electron paramagnetic resonance (EPR) spectroscopy for SnO 2 and Sb−SnO 2 as 2.12 and 2.15, respectively, confirmed oxygen vacancies. The Sb−SnO 2based HEC recorded a remarkable short circuit current density, I sc ∼ 23.2 mA/cm 2 , and peak output power, P out ∼ 32.2 mW/cm 2 . Antimony doping decreases the bulk resistance of the cell by 45 times due to highly accelerated OH − and H 3 O + conduction in Sb− SnO 2 HEC as observed by Nyquist plots. The defects-decorated Sb−SnO 2 -based HEC possesses an ultimate capability to replace solar cells and fuel cells.

Effect of Li+, Mg2+, and Al3+ Substitution on the Performance of Nickel Ferrite-Based Hydroelectric Cells

“…50 A tiny diffusion tail in the low-frequency region confirms the diffusion of ions in the materials. 13 A significant drop in the reactance of HECs from 10 5 to 10 6 Ω in dry conditions to an order of 10 Ω in wet conditions confirms the ionic conduction. 2 Fitting of Nyquist plots of NLFO, NMFO, and NAFO HECs in dry and wet conditions has been done to investigate further the charge transfer processes, and obtained parameters are tabulated in Table 3.…”

“…A Mg-doped alumina-based HEC delivered a maximum short-circuit current of around 16 mA . Shah et al enhanced the output short-circuit current of the SnO 2 HEC to a high value of 93 mA by doping antimony (Sb) in metallic form, which makes it a highly oxygen-deficient and reduced compound . We reported earlier the effect of synthesis temperature on the oxygen vacancies and short-circuit current of Li 0.3 Ni 0.4 Fe 2 O 4 and NiFe 2 O 4 . , …”

“…12 doping antimony (Sb) in metallic form, which makes it a highly oxygen-deficient and reduced compound. 13 We reported earlier the effect of synthesis temperature on the oxygen vacancies and short-circuit current of Li 0.3 Ni 0.4 Fe 2 O 4 and NiFe 2 O 4 . 14,15 As per the literature review, SnO 2 and spinel ferrite-based HECs have shown promising results.…”

In situ thermal exclusion induced Sb and Sb-doped SnO2 nanoheterostructuring and its improvements in cycling stabilities and rate capacities for Na+ storage

“…The peaks at 530.4 and 531.3 eV can be attributed to Sb 3+ and Sb 5+ in the ATO NPs, respectively, similar to ATO reported previously. 11,23 In addition, the distinct peak corresponding to the Sb 3d 5/2 of Sb 0 can also be observed at 528.8 eV. 24 It is different from the Sb 3d 5/2 spectrum of C@ATO/MWCNTs-etched, in which no peaks corresponding to Sb 0 can be identied (Fig.…”

“…This is in good accordance with the valence state of Sn in ATO. 11,23 Due to the overlapping between Sb 3d 5/2 and O 1s transition peaks, the Sb 3d 5/2 and O 1s spectra of C@Sb-ATO/MWCNTs are given in Fig. 2d.…”