APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Xiaoxu Zhao,Ziyang Lu,Maobin Wei,Menghan Zhang,Hongjun Dong,Chengwu Yi,Rong Ji,Yongsheng Yan
Developing high-efficiency and low-cost semiconductor photocatalysts with carbon layer modification has been proved to possess the potential advantage for dramatically improved photocatalytic performance in recent years. Here, a novel magnetic core-shell Fe 3 O 4 @C modified with Co 3 O 4 nanochains photocatalyst (Fe 3 O 4 @C/Co 3 O 4 ) is first constructed via a facile synthetic strategy using inexpensive and ordinary yeast as carbon source. The obtained composite structure is conducive to the transfer and separation of charge carriers due to the synergetic effect of carbon layer and Co 3 O 4 nanochains. In consequence, the photodegradation activity of various pollutants is significantly enhanced relative to that of pure Co 3 O 4 under visible light irradiation. Moreover, the introduction of magnetic materials makes this photocatalyst recycled easily by an external magnetic field and reused effectively without obvious activity loss. This work may provide a feasibility analysis and exemplificative strategy for using simple raw materials as carbon source to observably improve universal photocatalytic activity of composite semiconductor photocatalyst.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2020
·Vol. 51
·期 4
·1339-1343
·
IF 2.035
Ren Guoxing,Xiao Songwen,Liao Caibin,Xia Longgong,Liu Zhihong
The activity coefficient of CoO in SiO 2 -saturated MnO-SiO 2 slag was measured using metal-slag-gas equilibrium experiments under controlled oxygen potentials (10 −12 to 10 −10 atm) at 1623 K. The solubility of CoO in the slag increased with increasing oxygen potential and cobalt content in the alloy. The activity coefficient of cobalt oxide, γ CoO , referred to solid CoO, can be described as: γ CoO = 1.65 − 0.14 (wt pct CoO), where (wt pct CoO) represents the mass percent of CoO in the slag.
研究领域:
冶金学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2019
·
IF 0
Jian Du,Chao Li,Xilong Wang,Xiaoyue Shi,Han-Pu Liang
Developing high-performance and low-cost electrode for oxygen evolution reaction (OER) is a crucial step to produce clean and sustainable energy sources. Herein, we report mesoporous ultrathin cobalt oxides nanosheets (∼7 nm) grown on carbon cloth (denoted as CoOx/CC) as an efficient electrode for water oxidation. The electrode was fabricated via a simple calcination of cobalt alkoxyacetate grown on carbon cloth under air atmosphere. The as-synthesized CoOx/CC electrode exhibited better electrocatalytic performance for OER in 1.0 M KOH, with lower overpotential of ∼263 mV at 10 mA cm–2, lower Tafel slope of 56.07 mV dec–1, and better stability, in comparison with commercial IrO2 and Co3O4 nanoparticles. Also, the OER performance of CoOx/CC-10 is among the best of the reported cobalt oxides electrocatalysts. Detailed characterizations reveal that the interaction between cobalt oxides and CC, unique 3D structures, ultrathin nature of nanosheets, high specific surface area, nanoporous structures, and fast electron transfer rate contributed to the enhanced catalytic activity. More importantly, the synthetic strategy applied here has great potential application in large-scale production of efficient electrodes in water splitting technology.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
NANOTECHNOLOGY
·
2021
·Vol. 33
·期 7
·075401
·
IF 3.874
Bo-Qiang Miao,Yi-Ming Liu,Tian-Jiao Wang,Yu Ding,Yu Chen
For the electrochemcial hydrogen production, the oxygen evolution reaction (OER) is a pivotal half-reaction in water splitting. However, OER suffers sluggish kinetics and high overpotential, leading to the increase of overall energy consumption and decrease of the energy efficiency. In this work, high-quality cobalt oxide porous nanotubes (Co3O4-PNTs) are easily obtained by simple self-template approach. One-dimensional (1D) porous structure provides the large specific surface area, enough abundant active atoms and effective mass transfer. In addition, Co3O4-PNTs also own self-stability of 1D architecture, benefitting the their durability for electrocatalytic reaction. Thus, Co3O4-PNTs with optimal annealing temperature and time reveal the attractive alkaline OER performance (Tafel slope of 56 mV dec−1 and 323 mV overpotential at 10 mA cm−2), which outperform the Co3O4 nanoparticles and benchmark commercial RuO2 nanoparticles. Furthermore, Co3O4-PNTs also exhibit excellent OER durability for least 10 h at the 10 mA cm−2. Overall, Co3O4-PNTs with low cost can be serve as a highly reactive and economical catalyst for OER.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2020
·
IF 4.939
Shasha Zhu,Jinglei Lei,Lina Zhang,Jianxin He
The exploration of catalysts with high activity and low cost for water splitting is still necessary. Herein, a nanowire-like morphology CoO/NF electrode is synthesized using facile hydrothermal reaction and calcination treatment. The urea can regulate its morphology during the synthetic process of CoO/NF. Electrochemical studies reveal that the as-obtained CoO/NF exhibits excellent electrocatalytic performance with overpotential of 307 mV at current density of 10 mA cm −2 and Tafel slope of 72 mV dec −1 for oxygen evolution reaction , and CoO/NF delivers current density of 10 mA cm −2 at overpotential of 224 mV for hydrogen evolution reaction . The results of the oxygen evolution reaction stability show that the overpotential of CoO/NF electrode is only increased by 4 mV at current density of 10 mA cm −2 . The two-electrode water splitting with CoO/NF electrodes as both anode and cathode needs a cell potential of 1.76 V to reach 10 mA cm −2 . Therefore, this simple method to prepare CoO/NF electrode can enhance the properties of electrocatalysts , which makes CoO/NF a promising material to replace noble metal-based catalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2021
·
IF 9.028
Ying Xiong,Yumei Zhao,Xingkun Qi,Jiayi Qi,Yuanyuan Cui,Haibiao Yu,Ying Cao
In this paper, Gd-promoted Co3O4 catalysts were prepared via a facile coprecipitation method for low-temperature catalytic N2O decomposition. Due to the addition of Gd, the crystallite size of Co3O4 in the Gd0.06Co catalyst surprisingly decreased to 4.9 nm, which is much smaller than most additive-modified Co3O4 catalysts. This huge change in the catalyst’s textural structure endows the Gd0.06Co catalyst with a large specific surface area, plentiful active sites, and a weak Co–O bond. Hence, Gd0.06Co exhibited superior activity for catalyzing 2000 ppmv N2O decomposition, and the temperature for the complete catalytic elimination of N2O was as low as 350 °C. Meanwhile, compared with pure Co3O4, Ea decreased from 77.4 to 46.8 kJ·mol–1 and TOF of the reaction increased from 1.16 × 10–3 s–1 to 5.13 × 10–3 s–1 at 300 °C. Moreover, Gd0.06Co displayed a quite stable catalytic performance in the presence of 100 ppmv NO, 5 vol % O2, and 2 vol % H2O.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Qing Qu,Guo-Liang Pan,Yan-Ting Lin,Chang-Wei Xu
High efficient and low-cost electrocatalysts for the oxygen evolution reaction (OER) are essential components of renewable energy technologies . However, the high onset potential and limited active sites restrict the catalytic activity of current electrocatalysts. Therefore, we are motivated by the development of cheap and efficient catalytic electrodes to promote the sluggish water-splitting systems associated with the large-scale application of clean and renewable energy technologies. Herein, a novel, simple, and efficient routine is presented by noble metal particles embedded within mesoporous metal oxide materials as high-efficiency anode catalysts for OER. Highly ordered mesoporous Co 3 O 4 was prepared by a nanocasting method using the silica KIT-6 as hard template, showing an enhanced electrochemical performance. Then, M - Co 3 O 4 (M = Pt, Pd, Au) nanomaterials were prepared by a simple but novel chemical reduction method. They show the high surface area of 112.3, 81.0 and 73.6 m 2 g −1 , which can provide more active surface area exposure leads to shorter paths of charges from electrolyte to electrode surface . Moreover, a three-dimensional highly ordered mesoporous structure can facilitate diffusion and penetration of electrolyte and oxygen, and can also keep catalyst nanoparticles in a well-dispersed condition with more active sites. Electrochemical measurements revealed that 20, 50, 25 wt% are the best weight contents for M (M = Pt, Pd, Au) in the Co 3 O 4 with highest electrochemical activity (0.410, 0.415 and 0.422 V vs. SCE) and j 0.7V reaching a maximum value. M-Co 3 O 4 (M = Pt, Pd, Au) materials exhibit superior activities and excellent long-duration stability in alkaline attributed to accelerating the formation of Co(IV) cations after being introduced M(M = Pt, Pd, Au) nanoparticles within mesoporous Co 3 O 4 . This kind of noble metal embedded within mesoporous oxide catalysts will hold a large potential as a highly promising electrocatalyst in the future.
研究领域:
材料科学
·
能源技术
·
电化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Xiaona Ren,Fang Hou,Fangyuan Wang,Xiangwen Zhang,Qingfa Wang
We report a CeO 2 incorporated cobalt oxide electrode with abundant nano-sized interfaces. The as-prepared heterostructures exhibit remarkable oxygen evolution reaction (OER) activity and excellent stability, surpassing the pristine cobalt oxide and the state-of-art RuO 2 . Further DFT calculations and experimental results indicate that the improved OER performance of CoO-CeO 2 heterostructures originates from the hierarchically porous structure , large surface area and high electron density around Co sites. The armouphous phase is formed during OER test due to surface Ce leaching, which can further promoted the performance of the hybrids. This work elucidates the cooperative effects and in situ transformation of CeO 2 -incorporated cobalt oxide in water oxidation , providing a valuable guideline for designing electrocatalysts .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CARBON
·
2025
·
IF 11.6
Lin Xie,Ruilin Liu,Xiaomeng Jiang,Cui Ni,Baolei Wang,Chuanxin Hou,Di Lan,Wei Du,Xiubo Xie
In order to obtain multiple interfaces of Co/CoO by tuning the oxidation process and simultaneously clarify the interface migration, Co particles loaded on mangosteen shell-derived carbon (MSC) were prepared, and then oxidized under a mixed atmosphere of Ar/O 2 and 300 °C with different oxidation time. Due to the existence of MSC, the Co can completely oxidized in short time of 60 min and low O 2 concentration of 5 %. The oxidation process is: Co→CoO→Co 3 O 4 . A lot of defects in-situ formed in the oxidation process can be clearly detectable. Co/MSC composites oxidized at 300 °C for 10 min exhibits considerable minimum reflection loss of −37.86 dB and an effective absorption bandwidth of 5.28 GHz among the composites with different oxidation times. The Co/CoO, CoO/C, Co/C heterogeneous interfaces are conducive to the depletion of electromagnetic waves through interfacial polarization. The in-situ formed defects are positive for enhancing the dipole prolarization, and the natural resonance is also enhanced due to the presence of Co and its oxides. The positive effects of carbon additive in the oxidation of Co on the in-situ defects formation and multiple interface construction provide a new perspective for designing high performance microwave absorption materials.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2019
·
IF 5.383
Jian Du,Chao Li,Qunwei Tang
Vacancy enriched electrocatalysts are crucial in enhancing the catalytic activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) through a defect engineering. Herein, oxygen vacancies enriched Co 3 O 4 nanoflowers with single layer porous structures are made to study their catalytic activity toward water splitting. The as-synthesized defects enriched Co 3 O 4 presents flowers-like nanostructures and possesses high specific surface area (84 m 2 g −1 ) with uniform pore size (4 nm). On behalf of the unique morphology and electronic structure, the Co 3 O 4 nanoflowers display enhanced HER and OER performances compared with commercial Co 3 O 4 nanoparticles (∼50 nm). In addition, it still presents good catalytic without remarkably decay in potential over 9 days.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Lingyu Liu,Zihua Wang,Xue Zhong Wang
A modified sol-gel method employing alginic acid (H-ALG) granule as gelation media was developed for the synthesis of cobalt oxides in this investigation. High-temperature decomposition mechanism of alginic acid was studied using simultaneous thermogravimetric analysis (TGA) coupled with differential scanning calorimetry (DSC), infrared spectroscopy (IR) and mass spectrometry (MS). The main emissions were water, carbon dioxide and carbon monoxide with − 7444.8 J/g heat flow measured at temperatures between 200 and 500 °C. In contrast, the energy released using the cobalt alginate (Co-ALG) sample was determined as − 8296.2 J/g at this temperature range. The oxidation states of the Co-ALG sample gradually changed, resulting in a conversion from Co 3 O 4 to CoO at high temperatures. According to the powder X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis, single phase cubic Co 3 O 4 were produced with particle size ~25 nm after calcination at 500 °C for 2 h. The ability of H-ALG to attract metal ions, such as Co, could be considered as a low cost and simple route for a large scale production of high purity metal oxides at significantly low temperatures due to the tremendous amount of energy released during the combustion reaction of the alginate structure.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Wenyang Fu,Yingying Du,Jiana Jing,Chunhong Fu,Minghua Zhou
Electrochemical reduction of nitrate to ammonia (ERNA) is a new process to recycle nitrogen resource from nitrate polluted wastewater. Nevertheless, how to optimize active sites on electrode to improve activity is a key challenge. Here, we proposed that building interfacial electric field could enhance ERNA. XPS analysis, DFT calculations and in-situ electrochemical measurements confirmed that high Fermi level of Cu (1.09 eV) and low valence band maximum of CoO (−0.23 eV) formed interfacial electric field in CoO/Cu electrode to transfer electron from Cu to CoO, resulting in positively charged Cu (+0.01 eV) increase nitrate adsorption, whereas negatively charged CoO (−0.007 eV) decrease NO adsorption, improving removal and selectivity greatly for boosting ERNA. Eventually, CoO/Cu foam (Co/Cu ratio of 3.05) achieved the highest ammonia yield of 4.3 mg cm −2 h −1 with faradic efficiency of 96.7 %, surpassing Cu foam (1.2 mg cm −2 h −1 ) and CoO/Ni foam (1.3 mg cm −2 h −1 ) electrodes.
研究领域:
环境科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）