Corrosion-Guided Surface Engineering of Permalloy for Efficient Alkaline Oxygen Evolution Reaction.

The production of H via water electrolysis is limited by the kinetically sluggish oxygen evolution reaction (OER) that occurs on the anode of water electrolysis. In alkaline water electrolysis, OER is catalyzed equally well by non-noble metals-based catalysts. In this study, we report one such advanced OER electrocatalyst developed by an unconventional electrochemical anodization in acid from a readily available, abundant, and cheap permalloy (NiFe).

Eccentric Corrosion-Induced Formation of γ-NiFeOOH and γ-NiCoOOH on NiFeCo Alloy for Enhanced OER.

An indirect, swift, and easy method of enhancing the oxygen evolution reaction (OER) performance of an economically viable Fe-rich NiFeCo (NFC) alloy has been developed. This approach leverages the anodic potential sweeps applied indirectly to the counter electrode (CE) when one does cathodic hydrogen evolution reaction (HER) on by potential sweeping at the working electrode (WE). In this method, NFC was intentionally corroded indirectly by using it as a CE for the potential sweeping HER experiment done with a Pt WE.

Interface Size-Dependent Changes in Activity of Water Splitting Electrocatalysts.

The traditional method of reporting electrocatalytic activity by normalizing current to the geometric area (mA cm) often results in exaggerated activity for electrodes smaller than 1 cm. Using stainless steel 304 (SS-304) and Ni foam electrodes of varying sizes (0.3-2.

Molecular Simulation Insights into Acid Gas Interactions within Ni-Based Fluorinated Square-Pillared Metal-Organic Framework.

The increasing prominence of metal-organic frameworks (MOFs) in gas separation technologies has sparked significant interest in their application in flue gas treatment. Nevertheless, the adsorption of acidic gases in MOFs presents significant challenges owing to their complex interactions with the framework. The adsorption interactions of acidic gases and their mixtures with [Ni(1,4-pyrazine)(AlF)] (ALFFIVE-Ni-Pyr) are explored while considering the flexibility of the framework.

Achieving the optimal Ni(OH) : Pt ratio for enhancing electrocatalytic water-dissociation and H delivery in proton-deficient environments.

Despite the availability of abundant, inexpensive non-noble metal-based anode catalysts for alkaline water electrolysis, the cathodic hydrogen evolution reaction (HER) continues to be a challenge, even in the case of state-of-the-art Pt catalysts. In such proton-deficient environments, a metal hydroxide-/oxide-based co-catalyst that can help polarize the H-O bond in water has been found to promote proton abstraction and subsequent reduction into H on Pt and Ru surfaces. In this regard, the Ni(OH) : Pt co-catalyst is one of the best.

Ruthenium-infused nickel sulphide propelling hydrogen generation synergistic water dissociation and Volmer step promotion.

The inclusion of ruthenium (Ru) to decorate nickel sulphide (Ru@NiS/Ni foam) resulted in a highly efficient electrocatalyst for the alkaline HER by enhancing water dissociation at the interface and reducing the energy barrier of the Volmer step. This strategic fusion significantly boosts the catalyst's performance in facilitating hydrogen production.

An advanced Ru-based alkaline HER electrocatalyst benefiting from Volmer-step promoting 5d and 3d co-catalysts.

In this study, a trimetallic catalyst, NiWRu@NF, is electrodeposited onto nickel foam using chronoamperometry to enhance the hydrogen evolution reaction (HER) in alkaline water electrolysis. The catalyst combines nickel, tungsten, and ruthenium components, strategically designed for efficiency and cost-effectiveness, hydroxyl transfer and water dissociation, and acceleration of hydrogen combination, respectively. Evaluation of NiWRu@NF reveals exceptional performance, with a low overpotential of -50 mV and high current density of -10 mA cm, signifying its efficiency in promoting HER.

CuNi sulphidation maximizes MOR activity by expanding the accessibility of active sites!

Sulphidation of a CuNi alloy of Cu : Ni ratio 81 : 19 led to an exponential activity enhancement in the alkaline methanol oxidation reaction (MOR) by four fold due to an order of magnitude increase in the number of active Cu and Ni sites and improved charge transfer properties.

A tri-functional self-supported electrocatalyst featuring mostly NiTeO perovskite for H production methanol-water co-electrolysis.

A self-supported NiTeO perovskite is made by deploying an extended hydrothermal tellurization strategy with a restricted Te content, which was found to be exceptionally active towards the oxidation of water and methanol and the reduction of water in 1.0 M KOH where it delivered -10 mA cm at just -1.54 V for a full cell featuring MOR‖HER.

Ambiguities and best practices in the determination of active sites and real surface area of monometallic electrocatalytic interfaces.

Determining the number of electrocatalytically accessible sites (ECAS) and real surface area (RSA) for any given electrocatalyst precisely is important in energy conversion electrocatalysis as these are directly used in the determination of intrinsic activity markers. For monometallic electrocatalysts and electrocatalysts of just one type of active site, there believed to be ways of making precise determination of ECAS and RSA using underpotential deposition (UPD), stripping, and redox-charge integration employing transient voltammetric sweeping techniques. This transient nature of sweeping techniques makes the determination of ECAS and RSA relatively less reliable.

The Significance of Properly Reporting Turnover Frequency in Electrocatalysis Research.

For decades, turnover frequency (TOF) has served as an accurate descriptor of the intrinsic activity of a catalyst, including those in electrocatalytic reactions involving both fuel generation and fuel consumption. Unfortunately, in most of the recent reports in this area, TOF is often not properly reported or not reported at all, in contrast to the overpotentials at a benchmarking current density. The current density is significant in determining the apparent activity, but it is affected by catalyst-centric parasitic reactions, electrolyte-centric competing reactions, and capacitance.

Strategies and Perspectives to Catch the Missing Pieces in Energy-Efficient Hydrogen Evolution Reaction in Alkaline Media.

Transition metal hydroxides (M-OH) and their heterostructures (X|M-OH, where X can be a metal, metal oxide, metal chalcogenide, metal phosphide, etc.) have recently emerged as highly active electrocatalysts for hydrogen evolution reaction (HER) of alkaline water electrolysis. Lattice hydroxide anions in metal hydroxides are primarily responsible for observing such an enhanced HER activity in alkali that facilitate water dissociation and assist the first step, the hydrogen adsorption.

A review on recent developments in electrochemical hydrogen peroxide synthesis with a critical assessment of perspectives and strategies.

Electrochemical hydrogen peroxide synthesis using two-electron oxygen electrochemistry is an intriguing alternative to currently dominating environmentally unfriendly and potentially hazardous anthraquinone process and noble metals catalysed direct synthesis. Electrocatalytic two-electron oxygen reduction reaction (ORR) and water oxidation reaction (WOR) are the source of electrochemical hydrogen peroxide generation. Various electrocatalysts have been used for the same and were characterized using several electroanalytical, chemical, spectroscopic and chromatographic tools.

Developments in DNA metallization strategies for water splitting electrocatalysis: A review.

The biomolecule DNA with the presence of different functionalities found to interact with different kinds of metal ions and show relatively higher stability over a long period of time when optimized appropriately. With the presence of A-T and G-C pairs, sugar moieties, phosphate functional groups and the double-helical structure, it can assemble both cationic and anionic species and forms a perfect metal-DNA self-assembly. Depending upon the aspect ratio of metal-DNA self-assemblies, metal content and their morphological outcomes, they could deliver variance in the catalytic activities.

Ultrafast Growth of a Cu(OH)-CuO Nanoneedle Array on Cu Foil for Methanol Oxidation Electrocatalysis.

A swift potentiostatic anodization method for growing a 5-7 μm tall nanoneedle array of Cu(OH)-CuO on Cu foil within 100 s has been developed. This catalytic electrode when screened for methanol oxidation electrocatalysis in 1 M KOH with 0.5 M methanol, delivered a current density as high as 70 ± 10 mA cm at 0.

Amorphous Catalysts and Electrochemical Water Splitting: An Untold Story of Harmony.

In the near future, sustainable energy conversion and storage will largely depend on the electrochemical splitting of water into hydrogen and oxygen. Perceiving this, countless research works focussing on the fundamentals of electrocatalysis of water splitting and on performance improvements are being reported everyday around the globe. Electrocatalysts of high activity, selectivity, and stability are anticipated as they directly determine energy- and cost efficiency of water electrolyzers.

V Incorporated β-Co(OH): A Robust and Efficient Electrocatalyst for Water Oxidation.

Catalyzing oxygen evolution reaction (OER) with the lowest possible overpotential is a key to ensure energy efficiency in the production of hydrogen from water electrochemically. In this report, we show the results that astonished us. Co hydroxide containing trivalent V was prepared chemically and screened for electrochemical water oxidation in rigorously Fe free 1 M KOH (pH 13.

Advanced CuSn and Selenized CuSn@Cu Foam as Electrocatalysts for Water Oxidation under Alkaline and Near-Neutral Conditions.

Water electrolysis is a field growing rapidly to replace the limited fossil fuels for harvesting energy in future. In searching of non-noble and advanced electrocatalysts for the oxygen evolution reaction (OER), here we highlight a new and advanced catalyst, selenized CuSn@Cu foam, with overwhelming activity for OER under both alkaline (1 M KOH) and near-neutral (1 M NaHCO) conditions. The catalysts were prepared by a double hydrothermal treatment where CuSn is first formed which further underwent for second hydrothermal condition for selenization.

Spinel Cobalt Titanium Binary Oxide as an All-Non-Precious Water Oxidation Electrocatalyst in Acid.

Replacing precious water oxidation electrocatalysts used in proton exchange membrane (PEM) water electrolyzers with the nonprecious and abundant electrocatalysts is still a poorly addressed issue in the field of hydrogen generation in acidic medium through water electrolysis. Herein we report such an all-nonprecious binary spinel metal oxide the "cobalt titanate" (CoTiO) as an efficient alternate to expensive IrO and RuO for PEM water electrolyzer. The synthesized CoTiO octahedral nanocrystals of size 50 to 210 nm showed excellent oxygen evolution reaction (OER) activity in 0.

Nanosheets of Nickel Iron Hydroxy Carbonate Hydrate with Pronounced OER Activity under Alkaline and Near-Neutral Conditions.

Evaluation of unique catalysts of the iron group metals with activity in the OER region similar to that of scarce metals is of great importance to achieve sustainable production of H on a large scale. Herein, we report the unique nanosheets of nickel iron hydroxy carbonate hydrate (NiFeHCH) which were prepared through a wet-chemical route within 1 h of reaction time, acting as an efficient electrocatalyst for the oxygen evolution reaction (OER) in both alkaline and near-neutral media. The NiFeHCH was prepared with different concentrations of Fe in different ratios: 1:0.

NiTe Nanowire Outperforms Pt/C in High-Rate Hydrogen Evolution at Extreme pH Conditions.

Better hydrogen generation with nonprecious electrocatalysts over Pt is highly anticipated in water splitting. Such an outperforming nonprecious electrocatalyst, nickel telluride (NiTe), has been fabricated on Ni foam for electrocatalytic hydrogen evolution in extreme pH conditions, viz., 0 and 14.

Self-Assembled Molecular Hybrids of CoS-DNA for Enhanced Water Oxidation with Low Cobalt Content.

Water oxidation in alkaline medium was efficiently catalyzed by the self-assembled molecular hybrids of CoS-DNA that had 20 times lower Co loading than the commonly used loading. The morphological outcome was directed by varying the molar ratio of metal precursor Co(Ac) and DNA and three different sets of CoS-DNA molecular hybrids, viz. CoS-DNA(0.

Microwave-Initiated Facile Formation of NiSe Nanoassemblies for Enhanced and Stable Water Splitting in Neutral and Alkaline Media.

Molecular hydrogen (H) generation through water splitting with minimum energy loss has become practically possible due to the recent evolution of high-performance electrocatalysts. In this study, we fabricated, evaluated, and presented such a high-performance catalyst which is the NiSe nanoassemblies that can efficiently catalyze water splitting in neutral and alkaline media. A hierarchical nanoassembly of NiSe was fabricated by functionalizing the surface-cleaned Ni foam using NaHSe solution as the Se source with the assistance of microwave irradiation (300 W) for 3 min followed by 5 h of aging at room temperature (RT).

Core-Oxidized Amorphous Cobalt Phosphide Nanostructures: An Advanced and Highly Efficient Oxygen Evolution Catalyst.

We demonstrated a high-yield and easily reproducible synthesis of a highly active oxygen evolution reaction (OER) catalyst, "the core-oxidized amorphous cobalt phosphide nanostructures". The rational formation of such core-oxidized amorphous cobalt phosphide nanostructures was accomplished by homogenization, drying, and annealing of a cobalt(II) acetate and sodium hypophosphite mixture taken in the weight ratio of 1:10 in an open atmosphere. Electrocatalytic studies were carried out on the same mixture and in comparison with commercial catalysts, viz.