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OER nanoparticles

Nan Jia, Jing Liu, Yunshan Gao, Pei Chen, Xinbing Chen, Zhongwei An, Xifei Li, Yu Chen
An inexpensive and efficient bifunctional electrocatalyst for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), is central to the rechargeable zinc-air battery. Herein, a novel nanohybrid, N and S co-doped carbon nanotubes decorated with porous graphene layers encapsulated Co9S8 nanoparticles, was fabricated by one-step heat treatment process. The N, S doped species are major activity sites for the ORR, while Co9S8 nanoparticles are mainly responsible for the OER. Compared with commercial 20wt% Pt/C and Ir/C electrocatalysts, this nanohybrid exhibits comparable ORR half-wave potential (0...
March 20, 2019: ChemSusChem
Zhihe Liu, Hua Tan, Daobin Liu, Xiaobiao Liu, Jianping Xin, Junfeng Xie, Mingwen Zhao, Li Song, Liming Dai, Hong Liu
Many efforts have been made to develop bifunctional electrocatalysts to facilitate overall water splitting. Here, a fibrous bifunctional 3D electrocatalyst is reported for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) with high performance. The remarkable electrochemical performance is attributed of the catalysts to a number of factors: the metallic character of the three components (i.e., Ni3 N, CoN, and NiCo2 O4 ); the electronic structure, nanoflake-nanosphere network with abundant electroactive sites, and the electric field effect at the interfaces between different components...
March 6, 2019: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Umar Farooq, Ruby Phul, Saad M Alshehri, Jahangeer Ahmed, Tokeer Ahmad
Development of cost effective and efficient electrocatalysts is crucial to generate H2 as an alternative source of energy. However, expensive noble metal based electrocatalysts show best electrocatalytic performances which acts as main bottle-neck for commercial application. Therefore, non-precious electrocatalysts have become important for hydrogen and oxygen evolution reactions. Herein, we report the synthesis of high surface area (35 m2 /g) sodium niobate nanoparticles by citrate precursor method. These nanoparticles were characterized by different techniques like X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy...
March 14, 2019: Scientific Reports
Bae-Jung Kim, Emiliana Fabbri, Daniel F Abbott, Xi Cheng, Adam H Clark, Maarten Nachtegaal, Mario Borlaf, Ivano E Castelli, Thomas Graule, Thomas J Schmidt
Perovskite oxides have been at the forefront among catalysts for the oxygen evolution reaction (OER) in alkaline media offering a higher degree of freedom in cation arrangement. Several of highly OER active Co-based perovskites have been known to show extraordinary activities and stabilities when the B-site is partially occupied by Fe. At the current stage, the role of Fe in enhancing the OER activity and stability is still unclear. In order to elucidate the roles of Co and Fe in the OER mechanism of cubic perovskites, two prospective perovskite oxides - La0...
March 12, 2019: Journal of the American Chemical Society
Qiangbin Wang, Changhong Wang, Hongchao Yang, Yejun Zhang
Tuning the crystal phase of metal alloy nanomaterials has been proved a significant way to alter their catalytic properties based on crystal structure and electronic property. Herein, we successfully developed a simple strategy to controllably synthesize a rare crystal structure of hexagonal close-packed (hcp) NiFe nanoparticle (NP) encapsulated in a N-doped carbon (NC) shell (hcp-NiFe@NC). Then, we systemically investigated the oxygen evolution reaction (OER) performance of the samples under alkaline conditions, in which the hcp-NiFe@NC exhibits superior OER activity compared to the conventional face-centered cubic (fcc) NiFe encapsulated in a N-doped carbon shell (fcc-NiFe@NC)...
March 6, 2019: Angewandte Chemie
Jiao Du, Rui Wang, Ya-Ru Lv, Yong-Li Wei, Shuang-Quan Zang
Co/Co9S8 nanoparticles encapsulated in a N, S, and O ternary-doped carbon matrix were synthesized utilizing a Co-NSOMOF as a single precursor, and they exhibited excellent bifunctional electrocatalytic activity for the OER and HER. Impressively, the water splitting cell exhibited a low cell voltage of 1.56 V at 10 mA cm-2. The high performances were attributed to the synergistic effect and the protection of multi-heteroatom doped carbon shells for active Co/Co9S8 nanoparticles.
February 25, 2019: Chemical Communications: Chem Comm
Xiaopeng Han, Xiaofei Ling, Ying Wang, Tianyi Ma, Cheng Zhong, Wenbin Hu, Yida Deng
The size effect of transition metal nanoparticles on electrocatalytic performance remains ambiguous especially when decreasing the size to atomic level. Herein, we report the spatial isolation of cobalt species at atomic scale through tuning zinc dopants content in predesigned bimetallic Zn/Co zeolitic imidazole frameworks (ZnCo-ZIFs), affording the successful synthesis of nanoparticles, atomic clusters and single atoms of Co catalysts on N-doped porous carbon. This novel synthetic strategy allows the investigation of size effect on electrochemical behaviours from nanometer to angstrom...
February 21, 2019: Angewandte Chemie
Ryan H Manso, Prashant Acharya, Shiqing Deng, Cameron C Crane, Benjamin Reinhart, Sungsik Lee, Xiao Tong, Dmytro Nykypanchuk, Jing Zhu, Yimei Zhu, Lauren F Greenlee, Jingyi Chen
Controlling the 3-D morphology of nanocatalysts is one of the underexplored but important approaches for improving the sluggish kinetics of the oxygen evolution reaction (OER) in water electrolysis. This work reports a scalable, oil-based method based on thermal decomposition of organometallic complexes to yield highly uniform Ni-Fe-based nanocatalysts with a well-defined morphology (i.e. Ni-Fe core-shell, Ni/Fe alloy, and Fe-Ni core-shell). Transmission electron microscopy reveals their morphology and composition to be NiOx-FeOx/NiOx core-mixed shell, NiOx/FeOx alloy, and FeOx-NiOx core-shell...
February 18, 2019: Nanoscale
Zhengkun Yang, Changming Zhao, Yunteng Qu, Huang Zhou, Fangyao Zhou, Jing Wang, Yuen Wu, Yadong Li
The development of robust and efficient trifunctional catalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen reaction (HER) is central to regenerative metal-air batteries and overall water splitting. It is still a big challenge to achieve an efficient integration of three functions in one freestanding electrode. Herein, a facile and upscalable strategy is demonstrated, to construct cobalt nanoparticle-encapsulated 3D conductive films (Co/CNFs), which were induced by in situ solid diffusion from bulk cobalt metal...
February 5, 2019: Advanced Materials
Utpal Kayal, Bishnupad Mohanty, Piyali Bhanja, Sauvik Chatterjee, Debraj Chandra, Michikazu Hara, Bikash Kumar Jena, Asim Bhaumik
In recent years, several novel strategies for speeding up the slow kinetics of the water oxidation reaction have attracted considerable attention for generation of O2. This is particularly important from the environmental perspective. Here we report a SBA-15 type, 2D-hexagonal functionalized mesoporous organosilica material as support for small Ag nanoparticles (NPs) by grafting the silica surface with 3-aminopropyltriethoxysilane, followed by chemical impregnation of Ag NPs at its surface, to obtain a AgNPs@SBA-NH2 material...
January 25, 2019: Dalton Transactions: An International Journal of Inorganic Chemistry
Haitao Xu, Wenjing Liu, Yan Zhao, Di Wang, Jingzhe Zhao
Copper-based materials have attracted increasing attention for their earth-abundant and cheap characters for water splitting application. In the present work, a combined structure of Co3 O4 nanoparticles and CuO microsheets was constructed in an aqueous system and studied as an efficient oxygen evolution reaction (OER) electrocatalyst. NH3 molecules as the ligand of metal ions (Cu2+ and Co2+ ) played vital roles for the uniform growth of Co3 O4 @CuO microsheets. The synergetic contribution of the two components made the composite samples behave excellent OER activity and fast kinetics both on glassy carbon electrode (GCE) and nickel foam (NF) substrates in alkaline medium...
January 16, 2019: Journal of Colloid and Interface Science
Shuqi Liang, Ce Liang
High efficient electrocatalytic activity and strong stability to both oxygen reduction reaction (ORR) and oxygen evolution (OER) are very critical to rechargeable Zn-air battery and other renewable energy technologies. As a class of promising catalysts, the nanocoposites of transition metal nanoparticles that are encapsulated with nitrogen-doped carbon nanoshells are considered as promising substitutes to expensive precious metal based catalysts. In this work, we demonstrate the successful preparation of high-density cobalt nanoparticles encapsulated in very thin N-doped carbon nanoshells by the pyrolysis of solid state cyclen-Co-dicyandiamide complex...
January 12, 2019: Materials
Gang Ou, Fengchi Wu, Kai Huang, Naveed Hussain, Di Zu, Hehe Wei, Binghui Ge, Huizhen Yao, Lai Liu, Henan Li, Yumeng Shi, Hui Wu
Spinel oxides have attracted widespread interest for electrocatalytic applications owing to their unique crystal structure and properties. The surface structure of spinel oxides significantly influences the electrocatalytic performance of spinel oxides. Herein, we report a Li reduction strategy that can quickly tune the surface structure of CoFe2O4 (CFO) nanoparticles and optimize its electrocatalytic oxygen evolution reaction (OER) performance. Results show that a large number of defective domains have been successfully introduced at the surface of CFO nanopowders after Li reduction treatment...
January 9, 2019: ACS Applied Materials & Interfaces
Ye-Fei Li
Developing a robust catalyst for oxygen evolution reaction is the major challenge in the field of renewable energy. The difficulty comes from not only the low intrinsic activity but also the structural uncertainty of catalysts in the operating conditions. Therefore, finding the relationship between the structural evolution and the OER activity is urgent. At present, first-principles simulations have become a powerful tool to understand the mechanism of OER in atomic level. In this review, we take TiO2, MnOx, and CoS2 as examples to demonstrate how first-principles calculations can predict the morphology of nanoparticles, explore the pathway of electrochemically induced phase transition, and resolve the structure of a heterojunction...
January 6, 2019: ChemSusChem
Sinyoung Moon, Yun-Bin Cho, Areum Yu, Myung Hwa Kim, Chongmok Lee, Youngmi Lee
Nanocomposites of gold (Au) and iridium (Ir) oxide with various compositions (denoted as Au x Ir1- x O y , x = 0.05, 0.10 or 0.33, Au precursor molar ratio to Ir precursor) were synthesized via electrospinning and subsequent calcination method with two different solvent composition ratios of ethanol to N,N-dimethylformamide (DMF) in the electrospinning solution (ethanol:DMF = 70:30 or 50:50 v/v%). Simple single-step electrospinning successfully fabricated a hierarchical nanostructure having Au nanoparticles formed on fibrous main frames of Ir/IrO2 ...
December 24, 2018: ACS Applied Materials & Interfaces
Honghui Ning, Guoqiang Li, Yu Chen, Kaikai Zhang, Zhuang Gong, Renfeng Nie, Wei Hu, Qinghua Xia
A porous N-doped carbon encapsulated CoNi alloy nanoparticle composite (CoNi@N-C) was prepared using the bimetallic MOFs composite as precursor. The optimal prepared Co1Ni1@N-C material at 800 oC exhibited well-defined porosities, uniform CoNi alloy nanoparticle dispersion, a highly doped-N level, and scattered CoNi-Nx active sites, therefore afforded excellent oxygen catalytic activities towards the reduction and evolution process of oxygen. The ORR onset potential (Eonset) on Co1Ni1@N-C was 0.91 V and the half-wave potential (E1/2) was 0...
December 21, 2018: ACS Applied Materials & Interfaces
Shenglai Yao, Viktoria Forstner, Prashanth W Menezes, Chakadola Panda, Stefan Mebs, Eva M Zolnhofer, Matthias E Miehlich, Tibor Szilvási, Nanjundan Ashok Kumar, Michael Haumann, Karsten Meyer, Hansjörg Grützmacher, Matthias Driess
In large-scale, hydrogen production from water-splitting represents the most promising solution for a clean, recyclable, and low-cost energy source. The realization of viable technological solutions requires suitable efficient electrochemical catalysts with low overpotentials and long-term stability for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) based on cheap and nontoxic materials. Herein, we present a unique molecular approach to monodispersed, ultra-small, and superiorly active iron phosphide (FeP) electrocatalysts for bifunctional OER, HER, and overall water-splitting...
December 7, 2018: Chemical Science
Shumaila Ibraheem, Siguo Chen, Jia Li, Wei Li, XiaoYan Gao, Qingmei Wang, Zidong Wei
The electro-catalyzed oxygen reduction and evolution reactions (ORR/OER) are the key elements of many energy conversion systems, such as fuel cells, water electrolyzers and rechargeable metal-air batteries. Structural design of durable non-noble nanomaterials as bifunctional OER/ORR catalysts is a major drawback to commercial application. Herein, we exposed a strongly coupled hybrid material comprising of NiFeP-cubes nanoparticles supported on three-dimensional interconnected Fe,N-decorated carbon (3D-FeNC) as a robust bifunctional ORR/OER catalyst...
December 13, 2018: ACS Applied Materials & Interfaces
Dekun Wu, Qing Xu, Jing Qian, Xiaopeng Li, Yuhan Sun
Covalent organic frameworks (COFs) are a new class of crystalline porous polymers, which comprise mainly of carbons and are versatile for integrating heteroatoms such as B, O and N to the skeletons. The designable structure and abundant composition render COFs useful as precursors for heteroatom-doped porous carbons for energy storage and conversion. Herein, we describe a multifunctional electrochemical catalyst by pyrolysis of a bimetallic COF. The catalyst possesses hierarchical pores and abundant iron and cobalt nanoparticles embedded with standing carbon layers...
December 11, 2018: Chemistry: a European Journal
Lulu Chen, Wen Xiu Yang, Xiangjian Liu, Ling Long, Dandan Li, Jianbo Jia
The design of high-efficient and durable bi-functional oxygen electrocatalysts is still a great challenge. In this work, a novel Co9S8 nanoparticles/N,S-codoped defect-rich carbon nanotubes (Co9S8/N,S-CNTs) was fabricated by an ingenious template method. CdS nanowires, as a sacrificial template, can be removed simultaneously during the carbonization process without additional post-treatments. The large BET surface area (661.2 m2 g-1) and pore volume (1.49 cm3 g-1) of Co9S8/N,S-CNTs could largely enhance the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activities by facilitating the mass transportation and exposing more active sites...
November 27, 2018: Nanotechnology
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