Manganese dioxides for oxygen electrocatalysis in energy conversion and storage systems over full pH range

Yin, Mingming; Miao, He; Hu, Ruigan; Sun, Zixu; Li, Hong

doi:10.1016/j.jpowsour.2021.229779

Cited by 44 publications

(29 citation statements)

References 259 publications

(309 reference statements)

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“…[25] In addition, MnOx occurs in different kinds of stoichiometric forms, crystallographic phases, and geometric shapes (α, β, and δ-types), which are greatly alter their catalytic performance and stability. [26] Remarkably, MnO 2 has a various types of tunnel structures, such as the α-MnO 2 crystal lattice which is composed of [2 × 2] and [1 × 1] tunnel structures and tunnel size is 4.6 Å. The β-MnO 2 consists of [1 × 1] type tunnel structures and the tunnel size is 2.3 Å.…”

Section: Introductionmentioning

confidence: 99%

Development of α‐MnO₂ Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

et al. 2022

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Manganese oxides (MnO 2 ) with nanowire morphology materials are promising candidates for improving oxygen evolution and oxygen reduction reaction (OER/ORR) performance. In this work, we developed transition metal cation doping strategy into the α-MnO 2 tunnel structure to tune the Mn oxidation states and control the uniform nanowire morphology, crystalline structure to investigate the effect of doping over bifunctional activity. The single Ni 2 + cation doping in α-MnO 2 with various loading concentrations resulted in 8NiÀ MnO 2 exhibiting remarkable OER and ORR activity owing to their excessive concentration of Mn 3 + and Mn 4 + octahedral sites respectively. Further, Co 2 + cation doping in 8NiÀ MnO 2 leads to an enhanced synergistic effect that significantly improves the fraction of Mn 3 + quantity which is confirmed by average oxidation state. For electrochemical OER performance, 8CoÀ 8NiÀ MnO 2 exhibits a potential of 1.77 V, Tafel slope value of 68 mV dec À 1 and lower charge transfer resistance and it is active in ORR with more positive onset potential of 0.90 V, half-wave potential of 0.80 V, better current density (4.7 mA cm À 2 ) and a four-electron pathway. Moreover, bifunctional activity (ΔE = E OER @10 mA cm À 2 -ORR@E 1/2 ) of 8CoÀ 8NiÀ MnO 2 demonstrated 0.97 V, indicates an excellent activity in alkaline electrolyte solution.

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Section: Introductionmentioning

confidence: 99%

Development of α‐MnO₂ Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

et al. 2022

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“…We adopted an all-planar OECT configuration, wherein 4Cl-PDI-4EG and the mixture of MnO 2 nanoparticles (NPs) and 4Cl-PDI-4EG (MnO 2 NPs@ 4Cl-PDI-4EG ) were used as the n-type channel semiconductor and Au gate electrode coating, respectively. MnO 2 has the advantages of high earth abundance, low toxicity, and low cost and has shown to be a good catalyst for the decomposition of H 2 O 2 . , As depicted in Figure a (top), the two-electron oxidation of H 2 O 2 was catalyzed by MnO 2 NPs@ 4Cl-PDI-4EG on the gate electrode under a positive bias, which leads to the transfer of electrons to the gate electrode and changes the electrical double layer (EDL) at the gate/electrolyte interface, thereby decreasing the voltage drop at the gate/electrolyte interface and increasing the potential applied to the active channel, as indicated by Figure a (red dashed line, bottom). To simulate the physiological conditions, 10× PBS (phosphate-buffered saline) solution was used as the electrolyte.…”

Section: Results and Discussionmentioning

confidence: 99%

Efficient n-Type Small-Molecule Mixed Ion-Electron Conductors and Application in Hydrogen Peroxide Sensors

Liao

Chen

Lan

et al. 2022

ACS Appl. Mater. Interfaces

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Small-molecule semiconductors used as the channel of organic electrochemical transistors (OECTs) have been rarely reported despite their inherent advantages of well-defined molecular weight, convenient scale-up synthesis, and good performance reproducibility. Herein, three small molecules based on perylene diimides are readily prepared for n-type OECTs. The final molecules show preferred energy levels, tunable backbone conformation, and high film crystallinity, rendering them good n-type dopability, favorable volumetric capacities, and substantial electron mobilities. Consequently, the OECTs afford a record-low threshold voltage of 0.05 V and a normalized peak transconductance of 4.52 × 10–2 S cm–1, as well as impressive long-term cycling stability. Significantly, the OECTs utilized for hydrogen peroxide sensing are further demonstrated with a detection limit of 0.75 μM. This work opens the possibility of developing nonfullerene small molecules as superior n-type OECT materials and provides important insights for designing high-performance small-molecule mixed ion-electron conductors for OECTs and (bio)sensors.

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“…Accelerating consumption of fossil fuels and increasing public concerns on environmental issues have urged the implementation of energy conversion and storage devices. In particular, fuel cells and metal–air batteries are of interest owing to their environment friendliness and superior energy density. − In boosting oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics, these devices commonly use noble metal catalysts, such as Pt/C, RuO 2 , and Ir/C, which are scarce and expensive. − Furthermore, since electrochemical devices may perform at different pH conditions (e.g., polymer membrane fuel cells with acidic electrolyte, membrane bioreactor with neutral electrolyte, and metal–air batteries with alkaline or neutral electrolyte), the catalysts have to show excellent activity in broad pH value to promote universality and large-scale production. , …”

Section: Introductionmentioning

confidence: 99%

Cobalt Nanoparticles Encapsulated with N-Doped Bamboo-Like Carbon Nanofibers as Bifunctional Catalysts for Oxygen Reduction/Evolution Reactions in a Wide pH Range

Irmawati

Balqis

Destyorini³

et al. 2023

ACS Appl. Nano Mater.

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Nonprecious bifunctional oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) catalysts in wide pH electrolytes are crucial for the versatile use of electrochemical energy storage and conversion devices. Non-noble metal/nitrogendoped carbon (M−N/C) has been reported as a promising candidate for efficient and cost-effective bifunctional catalysts. Nevertheless, the stability and catalytic activity of M−N/C bifunctional catalysts in a wide pH range are still limited, especially in neutral and acidic electrolytes. Here, we synthesized directly grown N-doped bamboo-like carbon nanofiber-encapsulated cobalt nanoparticles on carbon flakes (Co−N/C fiber) via pyrolysis of 2D cobalt−zeolitic imidazolate framework and tubular g-C 3 N 4 . The in situ growth of N-doped carbon nanofiber incorporated with Co nanoparticles exposes large active sites and enhances charge transfer. Moreover, abundant mesopores with high loading of pyridinic-N, graphitic-N, Co@N/C, and Co−N x facilitate high catalytic activity in a wide pH condition. Co−N/C fiber shows superior ORR performance in alkaline, neutral, and acidic electrolytes with high onset potentials of 1.003, 0.820, and 0.800 V vs RHE, respectively. A comparable OER performance of Co−N/C fiber to the Ir/C benchmark in alkaline and neutral conditions can be obtained with 397 and 570 mV overpotentials at 10 mA cm −2 . Utilizing Co−N/ C fiber in alkaline and neutral Zn−air batteries exhibits power densities of 155 and 67 mW cm −2 , with excellent stability for over 180 h. This study offers a strategy for developing a bifunctional M−N/C catalyst that is applicable across a wide pH range via hybrid nanostructuring.

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Manganese dioxides for oxygen electrocatalysis in energy conversion and storage systems over full pH range

Cited by 44 publications

References 259 publications

Development of α‐MnO₂ Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

Development of α‐MnO₂ Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

Efficient n-Type Small-Molecule Mixed Ion-Electron Conductors and Application in Hydrogen Peroxide Sensors

Cobalt Nanoparticles Encapsulated with N-Doped Bamboo-Like Carbon Nanofibers as Bifunctional Catalysts for Oxygen Reduction/Evolution Reactions in a Wide pH Range

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Manganese dioxides for oxygen electrocatalysis in energy conversion and storage systems over full pH range

Cited by 44 publications

References 259 publications

Development of α‐MnO2 Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

Development of α‐MnO2 Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

Efficient n-Type Small-Molecule Mixed Ion-Electron Conductors and Application in Hydrogen Peroxide Sensors

Cobalt Nanoparticles Encapsulated with N-Doped Bamboo-Like Carbon Nanofibers as Bifunctional Catalysts for Oxygen Reduction/Evolution Reactions in a Wide pH Range

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Development of α‐MnO₂ Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst

Development of α‐MnO₂ Nanowire with Ni‐ and (Ni, Co)‐Cation Doping as an Efficient Bifunctional Oxygen Evolution and Oxygen Reduction Reaction Catalyst