Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 10
·5453-5462
·
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.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Hua Zhang,Wenjuan Fang,Wenran Wang,Nisheng Qian,Xiaohe Ji
The balance between band structure, composition, and defect is essential for improving the optoelectronic properties of ternary and quaternary quantum dots and the corresponding photovoltaic performance. In this work, ascorbic acid (AA) as capping ligand is introduced into the reaction system to prepare green Zn–Cu–In–Se (ZCISe) quantum dots. Results show that the addition of AA can increase the Zn content while decrease the In content, resulting in enlarged band gap, high conduction band energy level, and suppressed charge recombination. When AA/Cu ratio is 1, the quantum dots possess the largest band gap of 1.49 eV and the assembled quantum dot-sensitized solar cells exhibit superior photovoltaic performance with ∼17% increment mainly contributed by the dramatically increased current density. The new record efficiencies of 10.44 and 13.85% are obtained from the ZCISe cells assembled with brass and titanium mesh-based counter electrodes, respectively.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Huiming Li,Yang Wang,Wei Zhu,Zhongbin Zhuang
Searching for low-cost electrocatalysts with high activity towards the hydrogen evolution reaction (HER) is of great significance to enable large-scale hydrogen production via water electrolysis . In this study, by using inverse spinel MFe 2 O 4 (M = Mn, Fe, Co, Cu) nanoparticles (NPs) as the precursors, monodisperse bimetallic phosphide M-Fe-P NPs/C with hollow structures were readily obtained by a gas-solid annealing method. These hollow phosphide NPs displayed excellent HER activity in an acidic medium with a low loading amount of 0.2 mg cm −2 . In particular, the Co–Fe–P NPs/C shows highest HER activity that only requiring an overpotential of 97 mV to retain a current density of 10 mA cm −2 . A volcano relation between activity and incorporated elements was revealed. Incorporation of cation with high electronegativity stabilized the FeP active centres, while phase segregation resulted in the loss of activity for Cu–Fe–P NPs/C.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Rong Dai,Ziliang Zheng,Wenjun Yan,Chenshuai Lian,Xu Wu,Xia An,Xianmei Xie
The critical problem facing catalysts for the LT-ESR is deactivation owing to sintering of the active metal and carbon deposition. To solve this problem, a dragon fruit-like Pt-Cu@mSiO 2 catalyst for LT-ESR reaction has been successfully fabricated by a facile encapsulation strategy. Structural and morphological analysis shows that the Pt-Cu@mSiO 2 nanocomposite (approximately 400 nm) has a uniform dragon fruit-like structure, with well crystallized Pt-Cu alloy nanoparticles (about 50 nm) embedded in the mSiO 2 . Benefiting from the unique components and architectural features, the dragon fruit-like Pt-Cu@mSiO 2 nanocomposite with optimal Pt/Cu ratio present superior performance than that of Pt@mSiO 2 , Cu@mSiO 2 and supported Pt-Cu/mSiO 2 catalysts in terms of activity, H 2 selectivity, and stability in the LT-ESR reaction. Moreover, the synergistic effect of platinum and copper can substantially decrease the CO concentration. It is crucial that the mesoporous SiO 2 shell not only make the embedded Pt-Cu alloy nanoparticles easily accessible but also effectively prevent leaching and aggregation of active sites as well as spatially suppress the carbon deposition on the active surface, thus maintain a good catalytic activity during the 150 h stability test at 400 °C.
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy Materials
·
2019
·Vol. 9
·期 27
·1901396
·
IF 24.884
Hao Yang,Yu-wen Hu,Jun-jie Chen,M.-Sadeeq (Jie Tang) Balogun,Ping-ping Fang,Shanqing Zhang,Jian Chen,Yexiang Tong
The challenge in the artificial CO 2 reduction to fuel is achieving high selective electrocatalysts. Here, a highly selective Cu 2 O/CuO heterostructure electrocatalyst is developed for CO 2 electroreduction. The Cu 2 O/CuO nanowires modified by Ni nanoparticles exhibit superior catalytic performance with high faradic efficiency (95% for CO). Theoretical and experimental analyses show that the hybridization of Cu 2 O/CuO nanowires and Ni nanoparticles can not only adjust the d-band center of electrocatalysts to enhance the intrinsic catalytic activity but also improve the adsorption of COOH* intermediates and suppress the hydrogen evolution reaction to promote the CO conversion efficiency during CO 2 reduction reaction. An in situ Raman spectroscopic study further confirms the existence of COOH* species and the engineering intermediates adsorption. This work offers new insights for facile designing of nonprecious transition metal compound heterostructure for CO 2 reduction reaction through adjusting the reaction pathway.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2019
·
IF 3.674
Wei Wang,Feng Xu,Wenqiao Du,Long Zhang
A facile and efficient one-pot synthesis of methyl carbamate (MC) by urea and methanol was studied using metal modified fluorapatite as a catalyst. M 5 Ca 5 (PO 4 ) 6 F 2 (M 5 FAP, M = Co, Ni, Cu, Zn) was synthesized by co-precipitation. Among the catalysts, Zn 5 Ca 5 (PO 4 ) 6 F 2 (Zn 5 FAP) displayed the higher activity, selectivity and excellent stability after five times of reuse. A possible synthesis reaction mechanism over Zn 5 FAP catalyst was discussed.
✓ 已验证
产品关联
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 8
·5051-5063
·
IF 3.917
Wang Xue,Jiang Shengjun,Cui Sheng,Tang Yinhan,Pei Zifan,Duan Haoran
Abstract The pore structure of the regenerated cellulose hydrogel was used as a microreactor for generating magnetic MnFe 2 O 4 nanoparticles via in situ co-precipitation technology. Sodium periodate and sodium chlorite were used as oxidants, and the carboxyl modification of magnetic cellulose aerogels was achieved through a two-step oxidation reaction. The method used was convenient and environmental-friendly, and the raw materials were also green and non-toxic. The addition of magnetic nanoparticles promoted the adsorption and enabled the recycling of materials. The results showed that the adsorption equilibrium time was only 120 min and adsorption capacity could be increased by increasing the adsorption temperature. The maximum adsorption capacity of Cu(II) was 73.70 mg/g at 25 °C when the initial concentration of solution was150 mg/L. The adsorption behaviour towards Cu(II) followed the pseudo-secondary reaction kinetics and the Langmuir isotherm adsorption model. According to the results of XPS, carboxyl and hydroxyl groups were the main active adsorption sites for Cu(II). Moreover, all the composite aerogels exhibited good reusability and could be easily separated from the water after adsorption. Graphical abstract The pore structure of the regenerated cellulose hydrogel was used as a microreactor for generating magnetic MnFe 2 O 4 nanoparticles via in situ co-precipitation technology. Sodium periodate and sodium chlorite were used as oxidants, and the carboxyl modification of magnetic cellulose aerogels was achieved through a two-step oxidation reaction. According to the results of XPS, carboxyl and hydroxyl groups were the main adsorption sites for Cu(II). Moreover, all the composite aerogels exhibited good reusability and could be easily separated from the water after adsorption.
✓ 已验证
产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 7
·1-8
·
IF 5.479
Cao Yu,Wang Luona,Wang Chengyin,Su Dawei,Liu Yunling,Hu Xiaoya
A photoelectrochemical (PEC) sensor was constructed for the detection of non-electroactive malathion. It is based on the use of a hierarchical CuO material derived from a Cu-BTC metal-organic framework (where BTC stands for benzene-1,3,5-tricarboxylic acid). The modified CuO was obtained by calcination of Cu-BTC at a high temperature (300 °C) and possesses a high photocurrent conversion efficiency. Under irradiation with visible light and in the presence of malathion, the formation of the CuO-malathion complex on the CuO gave rise to an increase in steric hindrance. This results in a decrease in photocurrent. This novel PEC detection method has a lower detection limit of 8.6 × 10 −11 mol L −1 and a wide linear range (1.0 × 10 −10 ~ 1.0 × 10 −5 mol L −1 ).
Schematic presentation of the Cu-BTC MOF derived photoelectrochemical sensor for non-electroactive malathion detection.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano-Micro Letters
·
2020
·Vol. 12
·期 1
·1-13
·
IF 12.264
Pan Zhengbin,Han Ershuan,Zheng Jingui,Lu Jing,Wang Xiaolin,Yin Yanbin,Waterhouse Geoffrey I. N.,Wang Xiuguo,Li Peiqiang
Flower-like CeO 2 nanoparticles enhance the performance of CuO nanoparticle/Cu.
The system benefits from the heterojunction between p-type CuO and n-type CeO 2 .
The selective reduction of CO 2 to methanol on the target catalyst is studied.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2019
·Vol. 10
·期 1
·6
·
IF 4.034
Fangke Zhan,Juanjuan Yin,Jingxin Zhou,Tifeng Jiao,Lexin Zhang,Meirong Xia,Zhenhua Bai,Qiuming Peng
With the rapid development of industry, the problem of environmental pollution has become increasingly prominent. Exploring and preparing green, efficient, and low cost catalysts has become the key challenge for scientists. However, some conventional preparation methods are limited by conditions, such as cumbersome operation, high energy consumption, and high pollution. Here, a simple and efficient seed-mediated method was designed and proposed to synthesize a highly efficient bimetallic catalyst for catalyzing nitro compounds. A Pd-Cu bimetallic composite (BCM) can be prepared by synthesizing the original seed crystal of precious metal palladium, then growing the mature nanocrystalline palladium and supporting the transition metal copper. Importantly, after eight consecutive catalytic cycles, the conversion of the catalyzed 2-NA was 84%, while the conversion of the catalyzed 4-NP was still 72%. And the catalytic first order rates of 2-NA and 4-NP constants were 0.015 s−1, and 0.069 s−1, respectively. Therefore, current research of nanocomposites catalyst showed great significance for serious environmental pollution problems and the protection of living environment, providing a new idea for the preparation of new bimetallic catalytic materials.Keywords:seed-mediated;bimetallic catalyst;nanocomposites;catalyst
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 27
·期 2
·1888-1897
·
IF 2.914
Wang Ying,Wang Luxing,Deng Xiaoyan,Gao Hongtao
Waste biomass can be recycled to prepare biochar for soil restoration, in which process soil fertility would not be lost. In this work, biochar was prepared from waste pomelo peel, combined with ZnO, to be used to immobilize Cu(II) in contaminated soil, whose maximum adsorption capacity was up to 216.37 mg g −1 . Due to combination of ZnO, the BET surface area of biochar increased from 2.39 to 18.53 m 2 g −1 . Meanwhile, the surface functional groups increased, which was conducive to fixation of metal ion on the surface of biochar. Both pseudo-second-order kinetics and Langmuir isotherm model fit the experimental data well. Adsorption was easy to happen since the adsorption site on the surface of biochar/ZnO had a strong affinity with Cu(II). In addition, mechanism investigation indicated that Cu(II) was bond with biochar/ZnO mainly by non-bioavailable state (75.6%) primarily. It inferred that biochar/ZnO was an efficient and promising passivator in reducing heavy metal risk in soil.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of CO2 Utilization
·
2019
·
IF 5.189
Miao Wang,Xiaona Ren,Gang Yuan,Xiaopo Niu,Qingli Xu,Wenluan Gao,Shuaikang Zhu,Qingfa Wang
Element doping is an effective strategy to enhance the selectivity of electrochemical carbon dioxide reduction. In this work, a dendritic core-shell In-doped Cu@Cu 2 O catalyst is prepared by co-electrodeposition method on carbon fiber paper for selective electroreduction of CO 2 to CO. Faradaic efficiency of producing CO over this dendritic In-doped Cu@Cu 2 O reaches 87.6 ± 2.2% with total current density of 11.1 ± 0.85 mA cm −2 at −0.8 V vs RHE, which outperforms most of the reported Cu-based electrocatalysts. The excellent performance is mainly derived from charge re-distribution and the enhanced intrinsic activity due to the formation of In-doped Cu 2 O layer. Meanwhile, the Cu + /Cu 0 can be adjusted by tailoring the doped-In content. The relatively high ECSA and small charge transfer resistance are also conducive to improve the selectivity and activity. The oxyphilic In metal incorporated into the copper lattice can well stabilize the intermediate *COOH through enhancing interaction with O-ends of *COOH. This work provides a facile approach and a deep insight on design and synthesis of high efficiency hybrid electrocatalysts.
✓ 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）