Boosting efficient alkaline fresh water and seawater electrolysis via electrochemical reconstruction

Abstract

Electrochemical reconstruction is a powerful tool for generating highly active oxygen evolution reaction (OER) catalysts. Utilizing electrochemical reconstruction to fabricate an OER active catalyst based on a hydrogen evolution reaction...

Rational construction of loosely packed nickel nanoparticulates with residual HCOO ligands derived from a Ni-MOF for high-efficiency electrocatalytic overall water splitting

“…However, as for the Ni-250-2@NF, the newly emerged characteristic peaks located at 852.1 eV and 869.5 eV are assigned to metallic Ni (Ni 0 ). 26,53 Similarly, the peak positions of Ni 2p 3/2 and Ni 2p 1/2 in Ni-250-2@NF negatively shi by ∼1.6 eV as compared with that in the Ni-MOF precursor due to electronic interaction between the residuary HCOO ligand and generated metallic Ni NPs. When the calcination time was extended to 12 h, it is clear that there is a small positive shi of the binding energy of 0.2 eV for the Ni 0 peaks in Ni-250-12@NF compared with the Ni-250-2@NF sample.…”

“…51 However, aer calcination in the H 2 /Ar atmosphere, the spectra of Ni-250-2@NF and Ni-250-12@NF can be tted into three isolated peaks: Ni-O bonds originating from Ni-MOF, CO and adsorbed water molecules. 52,53 Furthermore, the content percent of the Ni-O peak can be calculated according to the areas that the tted curves enclose. It is clear that the content of the Ni-O bond gradually decreased from 16% to 2% with an increase of calcination time from 2 h to 12 h. This situation is in accordance with that of C 1s spectra, demonstrating that there is almost no HCOO species in the Ni-250-12@NF sample.…”

Coupling Ferrocyanide-Assisted PW/PB Redox with Efficient Direct Seawater Electrolysis for Hydrogen Production

“…The stability of the system was also evaluated by way of chronoamperometry, which showed that this approach exhibited considerable stability at 100 mA cm –2 with a retention rate of 95% within 45 h (Figure S18). To emphasize the advantage and potential of [Fe­(CN) 6 ] 4– -assisted PW/PB redox-coupled hydrogen production system, Figure e and Table S1 show the cell voltage, electricity consumption, and cell life of this work at a certain current density and compare it with those from different state-of-the-art seawater splitting experiments reported in the literature. ,− Our approach undoubtedly showed significant advantages in efficiency, energy consumption, and sustainability in H 2 production.…”

Lamella-heterostructured nanoporous bimetallic iron-cobalt alloy/oxyhydroxide and cerium oxynitride electrodes as stable catalysts for oxygen evolution

“…In this regard, it is of high desire to develop highly active, robust, and cost-effective OER electrocatalytic materials for highly efficient practical industrial electrolyzers. In view of the multi-proton-electron coupled OER taking place on the solid-liquid-gaseous interface of catalytic active sites 13 – 16 , ideal anodic materials should comprise adequate electroactive sites with high intrinsic activity to boost water oxidation reaction 3 , 17 , in addition to a rational and steady electrode structure that simultaneously facilitates electron transfer and mass transportation of OH − ions and H 2 O/O 2 molecules to/from sufficient available electroactive sites, and withstands violent gas evolution 18 – 20 . Despite judicious engineering of benchmarking precious-metal OER electrocatalysts such as RuO 2 and IrO 2 on steady conductive supports could satisfy these versatile requirements 16 , 21 , 22 , their scarcity, high cost and inferior durability substantially hamper the practical applications 23 , 24 .…”

“…However, most of them work well only at low current densities (<100 mA cm −2 ) for dozens of hours, unsatisfying the industrial requirements of practical electrolyzers 10 , 24 – 32 . This is probably because of their insufficient intrinsic activity of electroactive sites with too strong or too weak adsorption energies of *OH, *O, and *OOH intermediates 3 , 9 , 10 , 17 , as well as poor accessibility of electroactive sites and/or low electron transferability in industrial-scale electrode materials 18 – 20 , particularly for the ones made of traditionally low-dimensional nanocatalysts, which have to be casted on current collectors using polymer binder to maintain their electrical contact 18 – 20 , 27 , 28 , 43 , 44 . Therein, these nanocatalysts stack densely to inevitably bury most electroactive sites, inhibit mass transportation, and bring supplementary interfaces with high contact resistance, all of which lead to substantial overpotentials at the required high current densities 18 – 20 , 31 , 45 .…”