Dual‐Doping and Synergism toward High‐Performance Seawater Electrolysis

Abstract

Hydrogen (H2) production from direct seawater electrolysis is an economically appealing yet fundamentally and technically challenging approach to harvest clean energy. The current seawater electrolysis technology is significantly hindered by the poor stability and low selectivity of the oxygen evolution reaction (OER) due to the competition with chlorine evolution reaction in practical application. Herein, iron and phosphor dual‐doped nickel selenide nanoporous films (Fe,P‐NiSe2 NFs) are rationally designed as bifunctional catalysts for high‐efficiency direct seawater electrolysis. The doping of Fe cation increases the selectivity and Faraday efficiency (FE) of the OER. While the doping of P anions improves the electronic conductivity and prevents the dissolution of selenide by forming a passivation layer containing P–O species. The Fe‐dopant is identified as the primary active site for the hydrogen evolution reaction, and meanwhile, stimulates the adjacent Ni atoms as active centers for the OER. The experimental analyses and theoretical calculations provide an insightful understanding of the roles of dual‐dopants in boosting seawater electrolysis. As a result, a current density of 0.8 A cm−2 is archived at 1.8 V with high OER selectivity and long‐term stability for over 200 h, which surpasses the benchmarking platinum‐group‐metals‐free electrolyzers.

Spherical Ni3S2/Fe‐NiPx Magic Cube with Ultrahigh Water/Seawater Oxidation Efficiency

“…The peak around 691.7 cm –1 corresponds to the Fe–O vibrations in FeOOH, and the other two peaks at 486.8 and 546.5 cm –1 can be assigned to the E g bending vibration and the A 1g stretching vibration modes of Ni–O in NiOOH. [ 42 , 43 , 44 ] The broadening of the peak position and the blue‐shifted or red‐shifted for Ni‐O mode may be due to the structural defects of NiOOH or the presence of Ni(OH) 2 . [ 43 , 45 ]…”

“…The peak around 691.7 cm -1 corresponds to the Fe-O vibrations in FeOOH, and the other two peaks at 486.8 and 546.5 cm -1 can be assigned to the E g bending vibration and the A 1g stretching vibration modes of Ni-O in NiOOH. [42][43][44] The broadening of the peak position and the blue-shifted or red-shifted for Ni-O mode may be due to the structural defects of NiOOH or the presence of Ni(OH) 2 . [43,45] To gain insights into the surface reconstruction and the origin of the intrinsic activity, the energy barriers of the OER intermediates adsorption were analyzed by density functional theory (DFT) calculations.…”

PtCo@PtSn Heterojunction with High Stability/Activity for pH‐Universal H2 Evolution

“…So far, Pt-based materials are considered as the best catalyst to decrease the HER energy barrier, displaying outstanding activity. [9][10][11] However, Pt-based catalysts have distinct reaction pathways for HER in different pH solutions, which can lead to lower kinetics in alkaline media than in acidic media, [12] especially Volmer step. [13] Detailedly, PtH ad bonds are difficult to form in alkaline media because it derived from the dissociation of water.…”

An Efficient Symmetric Electrolyzer Based On Bifunctional Perovskite Catalyst for Ammonia Electrolysis

“…The phenomenon of different activating ions serving as active sites for catalytic reactions has also been reported in another study recently. [ 70 ]…”

“…The phenomenon of different activating ions serving as active sites for catalytic reactions has also been reported in another study recently. [70] To gain further insight into the surface reconstruction of the perovskite, Raman spectroscopy of the LNCO55-Ar was conducted before and after the electrolysis test (Figure 5h). Excluding the influence of carbon cloth, all samples presented three E g Raman modes located at 156 cm −1 , 435 cm −1 , and 551 cm −1 , which describe La displacements, Ni-O bond bending and Ni-O bond stretching respectively.…”