Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 10
·5453-5462
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IF 10.733
Yanling Qiu,Hexiang Zhong,Wenbin Xu,Taotao Zhang,Xianfeng Li,Huamin Zhang
The conversion of CO2 into value-added chemicals by employing renewable energy via an electrochemical process has received increasing attention. However, the low reaction rate and efficiency, as well as poor selectivity, have limited its further development. The low solubility of CO2 in an aqueous solution is one of the main factors that limit the reaction rate and selectivity of the electroreduction of CO2 (ERC) at a high overpotential. In this study, an organic additive containing an –NH2 group (methyl carbamate, MC) was incorporated into the ERC electrolyte for the first time. By utilizing the affinity interaction between a Lewis acid (the –NH3+ group formed by protonation of the –NH2 group) and a Lewis base (CO2), the ERC reaction rate was increased by 17%, and the faradaic efficiency for the production of CH4 reached 81.6%, which represented a large increase of 34% and surpassed that of most reported Cu electrodes. Furthermore, the partial current density for the production of CH4 was 31 mA cm−2 at −2.13 V (vs. RHE), which represents an increase of 30% in comparison with that in the blank system. In addition, the competitive hydrogen evolution reaction was substantially inhibited, and the decline in faradaic efficiency increased from 38.5% to 48.1% when the potential decreased gradually from −1.63 V to −1.98 V (vs. RHE). DFT calculations further indicate that the –NH3+ group can significantly promote the adsorption of CO* and CHO* on the Cu surface and increase the surface coverage of both intermediates. CHO* can be further stabilized by the –NH3+ group via the facilitation of partial electron transfer from Cu to C and the formation of H-bonds, which is favorable for further hydrogenation to form hydrocarbons. These results provide a simple and powerful way to increase the reaction rate and product selectivity of the reduction of CO2.
研究领域:
电化学
·
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Wenyang Fu,Zhongzheng Hu,Yingying Du,Pei Su,Yi Su,Qizhan Zhang,Minghua Zhou
The electrochemical reduction of nitrate to ammonia (ERNA) has become a green treatment technology for nitrate wastewater. However, strong adsorption for product caused high activation energy for product desorption in scaling relations, blocking activity of electrocatalyst in ERNA. Density functional theory (DFT) calculations indicated that constructing dual active sites (Cu and Co 3 O 4 ) could achieve strong adsorption of nitrate (−2.91 eV) with low desorbing energy barrier of ammonia (0.13 eV), breaking scaling relations. This dual active sites Co 3 O 4 /Cu electrode achieved a high ammonia yield rate of 684 µg mg cat − 1 h −1 with 94.6% faradic efficiency, surpassing single active site Co 3 O 4 and Cu electrodes. For mechanism, In-situ electrochemical characterization found the vital intermediates of *NH and *NH 2 , demonstrating that indirect reduction was the main pathway on Co 3 O 4 /Cu electrode. Thus, it is believed that building dual active sites on electrode is a reliable strategy to enhance ERNA for purifying industrial wastewater polluted by nitrate.
研究领域:
环境科学
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材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Junji Guo,Xungang Diao,Mei Wang,Zhi-Bin Zhang,Yizhu Xie
Electrochromic devices with unique advantages of electrical/optical bistability are highly desired for energy-saving and information storage applications. Here, we put forward a self-driven Al-ion electrochromic system, which utilizes WOx films, Cu foil, and graphite rod as electrochromic optical modulation and graph display electrodes, coloration potential supplying electrodes, and bleaching potential supplying electrodes, respectively. The inactive Cu electrode can not only realize the effective Al3+ cation intercalation into electrochromic WOx electrodes but also eliminate the problem of metal anode consumption. The electrochromic WOx electrodes cycled in Al3+ aqueous media exhibit a wide potential window (∼1.5 V), high coloration efficiency (36.0 cm2/C), and super-long-term cycle stability (>2000 cycles). The dynamic optical modulation and static graph display function can be achieved independently only by switching the electrode connection mode, thus bringing more features to this electrochromic system. For a large-area electrochromic system (10 × 10 cm2), the absolute transmittance value in its color-neutral state can reach about 41% (27%) at 633 nm (780 nm) by connecting the Cu and WOx electrodes for 140 s. The original transparent state can be readily recovered by replacing the Cu foil with the graphite rod. This work throws light on next-generation electrochromic applications for optical/thermal modulation, privacy protection, and information display.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RARE METALS
·
2024
·Vol. 43
·期 8
·3702-3712
·
IF 9.6
Mu Zi-Jie,Gao Yan-Jun,Dong Wen-Shuai,Li Zong-You,Song Qing-Yi,Huang Han-Jiao,Xing Li-Dong,Zhang Jian-Guo,Wang Wei,Yu Qi-Yao
The highly reversible insertion/extraction of large-radius K + into electrode materials remains a tough goal, especially for conversion-type materials. Herein, we design a current collector-integrated electrode (N–CoSe/CoSe 2 –C@Cu) as an advanced anode for potassium-ion battery (PIBs). The conductive CoSe/CoSe 2 heterojunction with rich Se vacancy defects, conductive sp 2 N-doped carbon layer, and the elastic copper foil matrix can greatly accelerate the electron transfer and enhance the structural stability. Consequently, the well-designed N–CoSe/CoSe 2 –C@Cu current collector-integrated electrode displays enhanced potassium storage performance with regard to a high capacity (325.1 mAh·g −1 at 0.1 A·g −1 after 200 cycles), an exceptional rate capability (223.5 mAh·g −1 at 2000 mA·g −1 ), and an extraordinary long-term cycle stability (a capacity fading of only 0.019% per cycle over 1200 cycles at 2000 mA·g −1 ). Impressively, ex situ scanning electron microscopy (SEM) characterizations prove that the elastic structure of copper foil is merged into the cleverly designed N–CoSe/CoSe 2 –C@Cu heterostructure, which buffers the deformation of structure and volume and greatly promotes the cycle life during the potassium/depotassium process. Graphical abstract
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2024
·
IF 4.1
Shixuan Wang,Liuyan Zhang,Chenrui Shi,Zeyi Guan,Gengzhe Shen,Guibin Tan,Yanmei Zhang
The development of an efficient and cost-effective electrocatalyst for the Hydrogen Evolution Reaction (HER) that can be widely applied in industrial settings poses a multifaceted challenge. This research involved fabricating a NiCo-LDH/Cu electrode as a self-supported catalyst for hydrogen evolution on nickel foam using a solvothermal method and constant potential electrodeposition. In comparison to the NiCu electrocatalyst produced through a single-step electrodeposition, the NiCo-LDH/Cu hydrogen evolution electrode prepared via this combined approach exhibited significant electrocatalytic performance for HER in an alkaline electrolyte. The NiCo-LDH/Cu catalytic electrode requires only an overpotential of 78.0 mV to achieve a current density of 10 mA·cm −2 in 1 M KOH. The current density required to catalyze the hydrogenation reaction is reduced by 64 % compared to pure nickel foam. This reduction accelerates the hydrogenation catalytic reaction and enhances electrochemical stability. The remarkable HER efficiency of the NiCo-LDH/Cu catalytic electrode primarily stems from the increased active surface area facilitated by the LDH structure and the synergistic impact generated during the NiCu co-deposition process. This work shows an economical and practical method for developing efficient non-precious metal catalytic electrodes.
研究领域:
材料科学
·
能源化学
✓ 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）