copper oer

The regulation of atomic and electronic structures of active sites plays an important role upon rational design of oxygen evolution reaction (OER) catalysts toward electrocatalytic hydrogen generation. However, the precise identification of the active sites for surface reconstruction behavior during OER remains elusive for water-alkali electrolysis. Herein, we report irreversible reconstruction behavior accompanied by copper dynamic evolution for cobalt iron layered double hydroxide (CoFe LDH) precatalyst to form CoFeCuOOH active species with high-valent Co species, identifying the origin of reconstructed active sites through operando UV-Visible (UV-Vis), in-situ Raman and X-ray absorption fine-structure (XAFS) spectroscopies...

A strategical approach for morphological transformation and heterojunction formation was utilized to suppress the shortcomings of uni-metal oxide electrocatalysts and enhance their bifunctionality. In situ generation of copper oxide (CuO) over the surface of manganese oxide (Mn2 O3 ) resulted in a morphological transformation from solid spheres to hollow spherical structures due to the ion-exchange diffusion (Kirkendall effect) of Cu ions into Mn2 O3 particles. This hollowness resulted in the advancement of the bifunctional electrocatalytic behavior of Mn2 O3 /CuO (overpotential (η10 ) of 280 mV for an OER and 310 mV for an HER at a current density of 10 mA/cm2 ) by virtue of increased exposed surface active sites aiding the adsorption of water molecules on the surface...

The design of highly active, economical and highly stable electrocatalysts for the oxygen evolution reaction (OER) is very important for realizing sustainable energy conversion. Herein, a Cu2 O/NiFeCo layered double hydroxide electrode on a copper foam (CF) with a nanoarray structure (Cu2 O/NiFeCo LDH/CF) is fabricated by using Cu(OH)2 on CF (Cu(OH)2 /CF) as a self-sacrificial template. The prepared Cu2 O/NiFeCo LDH/CF has a unique hierarchical nanostructure, high electrochemical active area and excellent integration of Cu2 O and NiFeCo LDH, resulting in low overpotentials of 228 mV and 269 mV for current densities of 10 and 100 mA cm-2 in 1 M KOH, respectively, as well as an ultrasmall Tafel slope of 40 mV dec-1 ...

Layered double hydroxides (LDH) are potential electrocatalysts to address the sluggish oxygen evolution reaction (OER) of water splitting. In this work, copper oxide (CuO/Cu2 O) nanoparticles are integrated with cobalt-manganese layered double hydroxide (CoMn-LDH) to enhance their performance towards OER. The catalyst is synthesized by growing CoMn-LDH nanosheets in the presence of CuO/Cu2 O nanoparticles that were obtained by the calcination of the copper containing metal-organic framework (HKUST-1). The synthesized CoMn-LDH@CuO/Cu2 O electrocatalyst shows excellent activity towards OER with an overpotential of 297 mV at a catalytic current density of 10 mA cm-2 and have a Tafel slope value of 89 mV dec-1 ...

Rational design of multi-structural defects in the transition-metal oxides is a very alluring and challenging strategy to significantly improve its oxygen evolution reaction (OER) performance. Herein, a simple and promising element doping approach is demonstrated to fabricate a poor-crystalline V-doping CuCo2 O4 (V-CuCo2 O4 ) nanoneedle with rich oxygen vacancies (Vo ), partially amorphous phase, and Co2+ defects on the carbon fiber (CF) (V-CuCo2 O4 /CF). The results indicate that the V doping could further weaken the crystallinity of V-CuCo2 O4 , providing the thoroughfares for the convenience of electrolyte penetration and the exposure of active sites...

Calcium Copper Titanium Oxide (CaCu3 Ti4 O12/ CCTO) has grasped massive attention for its colossal dielectric constant in high operating frequencies and wide temperature range. However, the synthesis and processing of CCTO directly influence the material's properties, imparting the overall performance. Researchers have extensively probed into these downsides, but the need for a new and novel approach has been in high demand. Modern synthesis routes and advanced non-conventional sintering techniques have been employed to curb the drawbacks for better properties and performance...

Although Zn-Ni/air hybrid batteries exhibit improved energy efficiency, power density, and stability compared with Zn-air batteries, they still cannot satisfy the high requirements of commercialization. Herein, the Cu+ /Cu2+ redox pair generated from a copper collector has been introduced to construct the hybrid battery system by combining Zn-air and Zn-Cu/Zn-Ni, in which CuX O@NiFe-LDH and Co-N-C dodecahedrons are respectively adopted as oxygen evolution (OER) and oxygen reduction (ORR) electrodes. For fabricating CuX O@NiFe-LDH, the Cu foam collector is oxidized to in situ form 1D CuX O nanoneedle arrays, which could generate the Cu+ /Cu2+ redox pair to enhance battery efficiency by providing an extra charging-discharging voltage plateau to reduce the charging voltage and increase the discharge voltage...

Nitrous oxide (N2 O) is a potent greenhouse gas (GHG) with limited use as a mild anesthetic and underdeveloped reactivity. Nitrous oxide splitting (decomposition) is critical to its mitigation as a GHG. Although heterogeneous catalysts for N2 O decomposition have been developed, highly efficient, long-lived solid catalysts are still needed, and the details of the catalytic pathways are not well understood. Reported herein is a computational evaluation of three potential molecular (homogeneous) catalysts for N2 O splitting, which could aid in the development of more active and robust catalysts and provide deeper mechanistic insights: one Cu(I)-based, [(CF3 O)4 Al]Cu ( A-1 ), and two Ru(III)-based, Cl(POR)Ru ( B-1 ) and (NTA)Ru ( C-1 ) (POR = porphyrin, NTA = nitrilotriacetate)...

Space charge transfer is crucial for an efficient electrocatalytic process, especially for narrow-band-gap metal sulfides/selenides. Herein, we designed and synthesized a core-shell structure which is an ultrathin MoSe2 nanosheet coated CuS hollow nanoboxes (CuS@MoSe2 ) to form an open p-n junction structure. The space charge effect in the p-n junction region will greatly improve electron mass transfer and conduction, and also have abundant active interfaces. It was used as a bifunctional electrocatalyst for water oxidation at a wide pH range...

Prussian blue analogues (PBAs) as a class of metal-organic frameworks demonstrate a promising platform to develop cost-effective high-performance electrocatalysts. However, the construction of delicate micro/nanostructures and controllable doping are still a challenging task for the fabrication of highly efficient copper-based electrocatalysts. Herein, we report a facile synthesis of copper foam supported Cu3 P@Co-Cu3 P (CH@PBA-P/CF) sub-microwire arrays as an active electrocatalyst for alkaline water splitting...

In the context of energy storage, the oxygen-evolution reaction (OER, 2H2 O → O2 + 4H+ + 4e- ) through the water-oxidation reaction is a thermodynamically uphill reaction in overall water splitting. In recent years, copper(II) coordination compounds have been extensively used for the OER. However, challenges remain in finding the mechanism of the OER in the presence of these metal coordination compounds. Herein, the electrochemical OER activity is investigated in the presence of a copper(II) coordination compound at pH ≈ 7...

High intrinsic activity of oxygen evolution reaction (OER) catalysts is often limited by their low electrical conductivity. To address this, we introduce copper inverse opal (IO) frameworks offering a well-developed network of interconnected pores as highly-conductive high-surface-area supports for thin catalytic coatings, for example the extremely active but poorly conducting nickel-iron layered double hydroxides (NiFe LDH). Such composites exhibit significantly higher OER activity in 1 M KOH than NiFe LDH supported on a flat substrate or deposited as inverse opals...

In literature, the creation of an interface between a highly conductive crystalline phase and an amorphous phase with unsaturated sites has been proven to be an effective strategy in the design of electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). However, the procedural complexity and limited formation of interfaces have compromised the envisioned effects. In this work, the dense crystalline Fe2 O3 /amorphous Cu interface was created simultaneously by the combination of solverthermal and annealing processes...

Electrically assisted water splitting is an endurable strategy for hydrogen production, but the sluggish kinetics of oxygen evolution reaction (OER) extremely restrict the large-scale production of hydrogen. Developing highly efficient and non-precious catalytic materials is essential to accelerate the sluggish kinetics of OER. However, currently used catalyst supports, such as copper foam, suffer from inferior corrosion resistance and structural stability, resulting in the disabled functionality of 3D conductive networks...

Exploring bi-functional electrocatalysts with excellent activity, good durability, and cost-effectiveness for electrochemical hydrogen and oxygen evolution reactions (HER and OER) in the same electrolyte is a critical step towards a sustainable hydrogen economy. Three main features such as high density of active sites, improved charge transfer, and optimized electronic configuration have positive effects on the electrocatalyst activity. In this context, understanding structure-composition-property relationships and catalyst activity is very important and highly desirable...

Transition metal sulfides (TMS) exhibit proliferated edge sites, facile electrode kinetics, and improved intrinsic electrical conductivity, which demand low potential requirements for total water splitting application. Here, we have propounded copper sulfide-coupled cobalt sulfide nanosheets grown on 3D nickel as an electrocatalyst for hydrogen (HER) and oxygen evolution (OER) reactions. The formation of djurleite copper sulfide with a Cu vacancy enables faster H+ ion transport and shows improved HER activity with a remarkably lower overpotential of 164 mV at 10 mA/cm2 , whereas cobalt-incorporated copper sulfide undergoes cation exchange during synthesis and shows elevated OER activity with a lower overpotential of 240 mV at 10 mA/cm2 for the OER...

Metal substrates are frequently used as current collectors and supports for electrochemically active materials, but their effect on the physical and electrochemical performance of electrocatalysts is rarely investigated. In this study, the electrodeposition method was used to coat four different metal meshes with three-dimensional nickel porous structures using hydrogen bubbles as a template. The significant influence of the metal substrates on the morphology of deposited nickel was demonstrated. 3D porous structures formed on nickel, iron, copper, and titanium meshes via the hydrogen bubble template method varied significantly...

To conserve resources and enhance the environmental performance, China has launched the "Zero waste" concept, focused on reutilization of solid waste and recovery of materials, including copper. Although several studies have assessed the copper demand and recycling, there is a lack of understanding on how different waste management options would potentially reduce primary copper demand and associated environmental impacts in China in the context of energy transition. This study addresses this gap in view of a transition to low-carbon energy system and the optimization of copper waste management combining MFA and LCA approaches...

The oxygen evolution reaction (OER) can provide electrons for reducing water, carbon dioxide, and ammonia. On the other hand, copper compounds are among the most interesting OER catalysts. In this study, water oxidation of a Cu foil in the presence of K2 FeO4 , a soluble Fe source, under alkaline conditions (pH ≈ 13) is investigated using electrochemical methods, X-ray diffraction, X-ray photoelectron spectroscopy, in situ visible spectroelectrochemistry, Raman spectroscopy, and scanning electron microscopy...

Electrochemical water splitting has been considered one of the most promising methods of hydrogen production, which does not cause environmental pollution or greenhouse gas emissions. Oxygen evolution reaction (OER) is a significant step for highly efficient water splitting because OER involves the four electron transfer, overcoming the associated energy barrier that demands a potential greater than that required by hydrogen evolution reaction. Therefore, an OER electrocatalyst with large surface area and high conductivity is needed to increase the OER activity...