Effects of Annealing Temperature on the Oxygen Evolution Reaction Activity of Copper–Cobalt Oxide Nanosheets

Kim, Geul Han; Park, Yoo Sei; Yang, Juchan; Jang, Myeong Je; Jeong, Jaehoon; Lee, Jihoon; Park, Han-Saem; Park, Taesung; Choi, Sung Mook; Lee, Jooyoung

doi:10.3390/nano11030657

Cited by 14 publications

(6 citation statements)

References 52 publications

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“…The TEM image manifests that the obtained HEO-800 nanoparticles have an average crystal size of 41.7 nm. However, the crystal size of the sample annealed at ≥900 °C (Figure S3) increases to about 57 nm, which is in line with previous reports . The high-resolution TEM (HRTEM) image of HEO-800 (Figure b) presented the lattice spacing of 0.29 and 0.25 nm, which correspond to (220) and (311) planes of cubic HEO, respectively.…”

Section: Resultssupporting

confidence: 90%

“…However, the crystal size of the sample annealed at ≥900 °C (Figure S3) increases to about 57 nm, which is in line with previous reports. 53 The high-resolution TEM (HRTEM) image of HEO-800 (Figure 3b) presented the lattice spacing of 0.29 and 0.25 nm, which correspond to (220) and (311) planes of cubic HEO, respectively. Meanwhile, the selected area electron diffraction (SAED) result shown in Figure 3c discloses the single-crystalline nature of the as-prepared HEO-800.…”

Section: Synthesis Of High Entropymentioning

confidence: 99%

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High-Entropy Oxide Derived from Metal–Organic Framework as a Bifunctional Electrocatalyst for Efficient Urea Oxidation and Oxygen Evolution Reactions

Fereja

Zhang

Fang

et al. 2022

ACS Appl. Mater. Interfaces

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High-entropy oxides (HEOs) offer unique features through a combination of incompatible metal cations to a single crystalline lattice. Owing to their special characteristics such as abundant cation compositions, high entropy stabilization, chemical and thermal stability, and lattice distortion effect, they have drawn ever-increasing attention for various applications. However, very few studies have been reported for catalytic application, and developing HEOs with large surface areas for efficient catalytic application is still in infancy. Herein, we design nanostructured HEO of (FeNiCoCrCu) 3 O 4 using metal−organic frameworks (MOFs) as sacrificial templates to achieve a large surface area, high density of exposed active sites, and more oxygen vacancies. Single-crystalline phase HEOs with surface area as large as 206 m 2 g −1 are produced and further applied as bifunctional electrocatalysts for the urea oxidation reaction (UOR) and oxygen evolution reaction (OER). Benefiting from enhanced oxygen vacancies and a large surface area with abundant exposed active sites, the optimized HEO exhibited excellent electrocatalytic activity toward UOR with a very low potential of 1.35 V at the current density of 10 mA cm −2 and showed long-term stability for 36 h operation, making a significant catalytic performance over previously reported HEOs. Moreover, the HEO demonstrated an efficient catalytic performance toward OER with a low overpotential of 270 mV at 10 mA cm −2 and low Tafel slope of 49 mV dec −1 . The excellent catalytic activity is ascribed to the starting MOF precursor and favorable high-entropy effect.

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Section: Resultssupporting

confidence: 90%

Section: Synthesis Of High Entropymentioning

confidence: 99%

High-Entropy Oxide Derived from Metal–Organic Framework as a Bifunctional Electrocatalyst for Efficient Urea Oxidation and Oxygen Evolution Reactions

Fereja

Zhang

Fang

et al. 2022

ACS Appl. Mater. Interfaces

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“…Moreover, the morphology of MOX thin films prepared by electrodeposition can also be tuned with annealing treatment. In this context, it was discovered that Co 3 O 4 nanosheets transform into nanoparticles upon heating at 300 °C or higher [ 103 ]. On the other hand, composite structures such as Ni–Cr 2 O 3 [ 104 ] and Cr 2 O 3 /Al 2 O 3 [ 105 ] were also prepared by electrodeposition.…”

Section: Synthesis Of P-type Mox Thin Filmsmentioning

confidence: 99%

P-Type Metal Oxide Semiconductor Thin Films: Synthesis and Chemical Sensor Applications

Moumen

Kumarage

Comini

2022

Sensors

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This review focuses on the synthesis of p-type metal-oxide (p-type MOX) semiconductor thin films, such as CuO, NiO, Co3O4, and Cr2O3, used for chemical-sensing applications. P-type MOX thin films exhibit several advantages over n-type MOX, including a higher catalytic effect, low humidity dependence, and improved recovery speed. However, the sensing performance of CuO, NiO, Co3O4, and Cr2O3 thin films is strongly related to the intrinsic physicochemical properties of the material and the thickness of these MOX thin films. The latter is heavily dependent on synthesis techniques. Many techniques used for growing p-MOX thin films are reviewed herein. Physical vapor-deposition techniques (PVD), such as magnetron sputtering, thermal evaporation, thermal oxidation, and molecular-beam epitaxial (MBE) growth were investigated, along with chemical vapor deposition (CVD). Liquid-phase routes, including sol–gel-assisted dip-and-spin coating, spray pyrolysis, and electrodeposition, are also discussed. A review of each technique, as well as factors that affect the physicochemical properties of p-type MOX thin films, such as morphology, crystallinity, defects, and grain size, is presented. The sensing mechanism describing the surface reaction of gases with MOX is also discussed. The sensing characteristics of CuO, NiO, Co3O4, and Cr2O3 thin films, including their response, sensor kinetics, stability, selectivity, and repeatability are reviewed. Different chemical compounds, including reducing gases (such as volatile organic compounds (VOCs), H2, and NH3) and oxidizing gases, such as CO2, NO2, and O3, were analyzed. Bulk doping, surface decoration, and heterostructures are some of the strategies for improving the sensing capabilities of the suggested pristine p-type MOX thin films. Future trends to overcome the challenges of p-type MOX thin-film chemical sensors are also presented.

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“…[ 82 ] In some cases, electrodepositing is used to generate intermediates before final products are obtained by post‐treatments, such as thermal annealing. [ 83 ]…”

Section: Synthesismentioning

confidence: 99%

Emerging 2D Copper‐Based Materials for Energy Storage and Conversion: A Review and Perspective

Ren

Wang

Chen

et al. 2022

Small

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extensive interest, [1][2][3] such as SCs, [4] rechargeable ion batteries, [5] water splitting, [6] metal-air batteries, [7] and CO 2 RR. [8] However, the practical applications of SCs and rechargeable ion batteries are limited by low energy density and low power density, respectively. [9,10] The multiple-electron transfer reactions in water splitting have posed a significant challenge that limits the catalytic efficiency and cycle stability. [11] At present, the urgent issue of metal-air battery is to design high-performance bifunctional electrodes. [12] For CO 2 RR, the technical realization is limited by the activity and selectivity of the catalyst, and the selectivity of its product beyond that of CO. [13,14] In these electrochemical devices, electrodes represent the core component, which dictates the efficiency, energy and power density, as well as catalytic activity and durability.Since the birth of graphene, 2D materials have attracted great attention due to their unique electrochemical, mechanical, and optical properties and diverse applications, as manifested in over 3000 academic papers each year. [15,16] 2D materials possess some structural advantages over the 0D and 1D counterparts by interlayer gap bonding and weak out-of-plane Van der Waals interaction, which provides an interesting platform for energy storage and conversion research. [17,18] So far, the 2D material family mainly includes transition metal dichalcogenides, transition metal carbides, layered metal oxides, layered double hydroxides and other graphene-like materials, such as black phosphorus. Of these, copper-based materials have received extensive attention because of high natural abundance, low price, high strength, arc erosion resistance, easy preparation of various nanoshapes, wear resistance, etc. (Figure 1), [19,20] leading to excellent electrochemical performance and advancement of electrochemical energy storage and conversion (Figure 2). For example, with a large surface area and potential size effect, CuO nanostructures, a p-type semiconductor, have excellent physical and chemical properties for SCs, as well as interesting magnetic and superhydrophobic properties, as compared with other metal oxides, such as TiO 2 , ZnO, WO 3 , and SnO 2 . [21] Cu-S compounds are a promising lithium cathode with a high energy density and long cycling stability. [22] Cu-Se is also considered as a novel cathode 2D materials have shown great potential as electrode materials that determine the performance of a range of electrochemical energy technologies. Among these, 2D copper-based materials, such as Cu-O, Cu-S, Cu-Se, Cu-N, and Cu-P, have attracted tremendous research interest, because of the combination of remarkable properties, such as low cost, excellent chemical stability, facile fabrication, and significant electrochemical properties. Herein, the recent advances in the emerging 2D copper-based materials are summarized. A brief summary of the crystal structures and synthetic methods is started, and innovative strategies for improving electro...

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Effects of Annealing Temperature on the Oxygen Evolution Reaction Activity of Copper–Cobalt Oxide Nanosheets

Cited by 14 publications

References 52 publications

High-Entropy Oxide Derived from Metal–Organic Framework as a Bifunctional Electrocatalyst for Efficient Urea Oxidation and Oxygen Evolution Reactions

High-Entropy Oxide Derived from Metal–Organic Framework as a Bifunctional Electrocatalyst for Efficient Urea Oxidation and Oxygen Evolution Reactions

P-Type Metal Oxide Semiconductor Thin Films: Synthesis and Chemical Sensor Applications

Emerging 2D Copper‐Based Materials for Energy Storage and Conversion: A Review and Perspective

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