CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Zhuocheng Yin,Yuyu Bu,Jun Ren,Shuai Chen,Daming Zhao,Yihui Zou,Shaohua Shen,Dongjiang Yang
Tungsten trioxide (WO 3 ) is believed to be a promising electrode candidate for supercapacitors, due to its reversible surface redox reaction resulted from the almost same W-O bond lengths with different oxidation states. However, the specific capacitance of WO 3 electrode is very low (<250 mF cm −2 ) because of its low conductivity and slow surface redox reaction kinetics. Herein, to address these issues, mesoporous WO 3 nanosheets with exposed (2 0 0) facets were anchored on activated carbon cloth (ACC) via a simple two-step process including heat treatment and alcohol-thermal process. The ACC was coated on WO 3 seeds and proceed a heat treatment at 500 °C and the time of alcohol-thermal process were 7 h, 8 h, and 9 h labeled as WO 3 @ACC- n ( n = 7, 8, 9). SEM and TEM images confirmed the WO 3 nanosheets were successful anchored on the ACC. The WO 3 @ACC-8 electrode showed the best specific areal capacitance which could reach as high as 659 mF cm −2 at a current density of 5 mA cm −2 and superior stability with almost no decrease in 10,000 cycles in the presence of Na 2 SO 4 as the neutral electrolyte. The capacitance is encouragingly much higher than the previously reported values in a three-electrode system in the neutral aqueous condition. DFT calculations reveal that, in comparison to the (0 0 2) and (0 2 0) facets, the exposed (2 0 0) facets of the mesoporous WO 3 nanosheets triggers the superior Na + adsorption, which accelerates the Na + -involved surface redox reaction for the boosted supercapacitor performance. A flexible asymmetric supercapacitor (FASC) was fabricated from the WO 3 @ACC electrode, which exhibits high energy density (0.5 mWh cm −3 ) and power density (62 mW cm −3 ) without any attenuation during ±180° wide-angle bending.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Rui Ling,Shuting Zhao,Chenxiao Meng,Wenyun Wang,Chao Yang,Wentao Qi
Extending the layer spacing of the (001) planes to regulate the mobility of Zn 2+ is widely adopted to optimize the performance of VOPO 4 ·2H 2 O cathode for zinc-ion batteries. However, the unique function originating from other planes is often neglected. Herein, an effective in situ conversion methodology is proposed for the synthesis of the (200) oriented growth of vertical VOPO 4 ·2H 2 O nanosheets with oxygen vacancies (V Od -VOPO 4 ). Theoretical simulation and ex situ characterizations collaboratively demonstrate that the richly exposed (200) plane with tetragonal channels can offer quick pathways for in-layer and cross-layer migration of Zn 2+ , exhibiting enhanced transfer kinetics with improved reversible capacity. Meanwhile, efficient electron migration in V Od -VOPO 4 is guaranteed by the introduction of oxygen vacancies. Thus, the as-prepared V Od -VOPO 4 harvests exceptional discharge capacity, impressive rate capability, and remarkable long-cycle stability at high mass loading. Notably, the V Od -VOPO 4 electrode (15 mg cm −2 ) provides a capacity of 213.5 mAh g −1 with an ultrahigh areal capacity of 3.02 mAh cm −2 at 0.1 A g −1 , showing great potential for applications. This study highlights the orientated growth strategy for facilitating ion storage and migration, offering novel perspectives on the development of high-performance electrodes and beyond.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2021
·
IF 13.084
Lipeng Wu,Bin Li,Yang Li,Xiaobin Fan,Fengbao Zhang,Guoliang Zhang,Qing Xia,Wenchao Peng
Herein, a series of Co@N–C materials are synthesized using nitrates (LiNO3, NaNO3, and KNO3) as templates to control the preferential growth of the cobalt (200) facet. Co@N–C–X (X = LiNO3, NaNO3, and KNO3) exhibit excellent activities and long-term stabilities for Fenton-like degradation of bisphenol A (BPA) with peroxymonosulfate (PMS) as an oxidant. The texture coefficient (TC) is used to investigate the relationship between the Co facets and their catalytic activities, and a linear relation is built between the TC of Co(200) and the reaction rate constant (k). Co(200) is therefore the most active facet for PMS activation, while nitrates can promote the preferential growth of the Co(200) facet. Moreover, the Co(200) facet is more stable against leaching and can achieve more quick transformation between Co2+/Co3+. Quenching tests, electron paramagnetic resonance spectra, and electrochemical tests show that singlet oxygen (1O2) plays the dominant role for BPA degradation. Density functional theory verifies that Co nanoparticles coated with a graphitic nitrogen-doped carbon layer have the best activity for PMS activation. This work first proposes the strategy of using nitrates to control the preferential growth of Co facets and reveals the relationship between the TC value and k, thus attracting great interest in the environmental field.
研究领域:
环境科学
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催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 14
·10338-10350
·
IF 2.993
Xiao Yong-Hao,Yu Yu-Xiang,Zhang Wei-De
Novel visible-light-driven WO 3 nanorod arrays with oriented (200) facet were successfully synthesized via a facile solvothermal process using mixed ethanol and water as solvents. Subsequently, WS 2 quantum dots (QDs) derived from bulk WS 2 powder via ultrasonication were interspersed on WO 3 nanorod arrays. The presence of suitable volume ratio of ethanol is a key factor to achieve greater exposure of the WO 3 (200) facet. The morphologies, microstructures and optical properties of the prepared samples were systematically explored. The results illustrated that the preferential exposure on the (200) facet of WO 3 nanorods as well as the efficient relative electrochemically active surface areas provided by WS 2 QDs could facilitate the charge transfer between WS 2 QDs and the (200) facet of WO 3 nanorods. This study provides a promising approach to design high performance photoanodes for photoelectrochemical water splitting.
研究领域:
材料科学
·
光化学
·
纳米技术
·
能源材料
✓ 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）