JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 13
·8079-8090
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IF 4.22
Liu Jiali,Yang Qiang,Liu Jikai,Luo He’an
Tungsten trioxide (WO 3 ) has been conceived as a promising photoanode material for photoelectrochemical (PEC) water oxidation. Therefore, many efforts have been made to improve its PEC performances. Herein, a novel heterojunction is fabricated through combining rocksalt CoO (R-CoO) or blende CoO (B-CoO) nanosheets with WO 3 nanoplates using a spin-coating method. The typical type II heterojunctions, e.g., WO 3 /R-CoO and WO 3 /B-CoO, both have exhibited higher photocurrent densities than pristine WO 3 photoanode. The photocurrent densities of WO 3 /R-CoO, WO 3 /B-CoO and WO 3 are 0.53 mA cm −2 , 0.45 mA cm −2 and 0.31 mA cm −2 at 1.23 V vs. reversible hydrogen electrode, respectively. For the WO 3 /R-CoO photoanode, the surface charge separation efficiency is 50.95% and the photoconversion efficiency is 0.062%, which are both higher than the WO 3 and WO 3 /B-CoO photoanodes. The enhanced PEC performances are due to the type II heterojunction between WO 3 and R-CoO (or B-CoO), which facilitates the absorption of visible light and charge transport. The better performance of WO 3 /R-CoO than that of WO 3 /B-CoO may be due to the deeper valence band position of R-CoO. Our work demonstrates that R-CoO (or B-CoO) can couple with WO 3 to form a type II heterojunction to improve the PEC water oxidation performance.
研究领域:
材料科学
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光电化学
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2023
·
IF 9.4
Zongliang Yu,Shunxiang Wang,Zuoan Xiao,Fen Xu,Cuili Xiang,Lixian Sun,Yongjin Zou
Transition metal oxides are excellent electrode materials for supercapacitors because of their high theoretical capacitance, good stability, environmental friendliness, and tunable structure. In this study, Cu 2 O-CoO heterojunction materials loaded on graphene oxide (Cu 2 O-CoO/GO) are prepared via the precipitation, hydrothermal, and heat treatment processes . Through the adsorption of transition metal ions by the oxygen-containing functional groups of GO, followed by alkali titration as well as hydrothermal reaction of Cu 2+ and Co 2+ ions, the hydroxides of metals are adsorbed on GO. Meanwhile, the reduced GO completes the self-assembly, and the GO with good spatial structure supports the formation of Cu 2 O-CoO heterojunction structure. The Cu 2 O-CoO/GO electrode material combines the high conductivity of GO with the excellent internal conductivity of Cu 2 O-CoO, and its abundant active sites and specific surface area, thereby ensuring good electrochemical performance. Thus, it enables reversible ion adsorption and desorption, exhibits the pseudocapacitance of copper oxide and cobalt oxide, and has higher capacitance performance than Cu 2 O/GO and CoO/GO electrodes. The specific capacitance of Cu 2 O-CoO/GO at 1 A g −1 is 723 F g −1 . Cu 2 O-CoO/GO/ASC exhibits an energy density of 44.1 Wh kg −1 at 794 W kg −1 and capacitance retention rate of 89.3 % after 10,000 cycles. This indicates that the material has significant potential for a wide range of supercapacitor applications.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2021
·Vol. 25
·期 2
·148-158
·
IF 3.106
Bao Er-Peng,Dong Ruichen,Zhang Shuoqing,Li Huan,Zhang Weiguo,Zou Jijun,Xu Qiang
The photocatalysis of graphtic carbon nitride (g-C 3 N 4 ) material has been widely used for the photocatalytic degradation of organic pollutants. However, g-C 3 N 4 still has some drawbacks, such as the high recombination of photo-induced electron–hole pairs and weak absorption of light irradiation. To further improve the photodegradation performance of g-C 3 N 4 , a novel composite photocatalyst (CoO/ PT-C 3 N 4 ) has been prepared by using a one-pot calcination method, in which cobalt oxide (CoO) as a cocatalyst are introduced on the rectangular hollow substrate of g-C 3 N 4 (PT-C 3 N 4 ), The CoO/PT-C 3 N 4 composite photocatalyst delivers an excellent photodegradation performance for diesel oil under a simulated sunlight. It exhibits a high degradation efficiency of 95.92% after light irradiation for 2 h, which is much higher than that of pristine PT-C 3 N 4 . Free radical capture experiments manifest that the free radical of ·O 2− plays a major role for the photodegradation and main active radicals abide by the sequence: ·O 2− > ·OH > h + . Moreover, the CoO/PT-C 3 N 4 composite photocatalyst delivers an excellent cyclic stability, which only degrades 8.71% photodegradation efficiency after 10 cycles. The improvement of CoO/PT-C 3 N 4 composite photocatalyst is ascribed to the formation of a heterojunction between CoO and PT-C 3 N 4 , which promotes the separation of photo-induced carriers. This work paves a new way for the exploration of photocatalyst for the organic pollutant degradation.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Yan Li,Mengna Ding,Guoxiang Yang,Lei Wang,Liulin Luo,Yingchun Miao,Yuning Huo
Acinetobacter baumannii ( A. baumannii ) was widely existed in medical wastewater and easily induced infections to threaten the human healthy. We herein reported Ag/CoO-N photocatalyst composites for effective inactivation of A. baumannii . Ag/CoO-N composites were prepared by N-doping to CoO crystal in supercritical fluid followed with photo-reduction of Ag under visible-light irradiation. N-species was incorporated in the crystal structure of CoO, on which uniform Ag nanoparticles were stably deposited. Thus, the satisfactory photocatalytic sterilization of A. baumannii irradiated by visible-light irradiation was attributed to the high capability of light trapping and the efficient separation of photo-charges. Due to photo-induced electrons as the main active species, Ag nanoparticles and CoO-N synergistically realized mineralization of cell membrane, which lead K + ions leak from cell to crack structure of bacteria, the decrease of genetic materials, and the cripple of the self-repair function in bacteria, resulting in the final cell death.
研究领域:
微生物学
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材料科学
·
医学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2023
·Vol. 13
·期 4
·1128-1139
·
IF 5
Peijing Guo,Shaoyu Yuan,Bingrong Guo,Siwei Li,Yongjun Gao
A CoO–CdS heterostructured photocatalyst CC-2-300 loaded with carbon derived from the biomass material chitosan was synthesized. Under visible-light irradiation, the photocatalytic hydrogen evolution rate can reach up to 10.60 mmol gcat−1 h−1, which is 7.21 times higher than that of pure CdS under the same conditions, with good cycle stability and high apparent quantum efficiency. The control experiments and characterization results prove that the chitosan-derived carbon supported CoO nanorods and CdS nanoparticles are cross-distributed to form a direct Z-scheme heterojunction, which improves the migration efficiency of photogenerated carriers and effectively slows down the recombination rate of photogenerated charges and holes on CdS that is susceptible to photocorrosion, thus improving the efficiency of photocatalytic hydrogen evolution.
研究领域:
材料科学
·
能源科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Weimo Li,Meixuan Li,Ce Wang,Yen Wei,Xiaofeng Lu
Rational design of highly efficient electrocatalyst for oxygen evolution reaction (OER) is essential to construct high-performance energy devices. In this study, we have developed an electrospinning, in situ polymerization and carbonization process to fabricate Fe doped CoO/C (Fe-CoO/C) nanofibers as efficient OER electrocatalysts. In the synthesized Fe-CoO/C nanofibers, ultrathin carbon layer can be used as conductive network to promote electron transfer and thus improve the electrocatalytic activity. At the same time, additional active sites, like bridged site, formed by Fe doping, also provides the catalyst excellent electrochemical activity in OER. The as-prepared Fe-CoO/C nanofibers exhibit an excellent OER activity with an overpotential of 362 mV at the current density of 10 mA cm −2 in an alkaline medium, which is comparable with the commercial RuO 2 catalyst. After 2500 cyclic voltammograms (CVs) cycles test, the catalyst still maintains the initial electrocatalytic activity, demonstrating a great durability. This strategy introduces both carbon layer and Fe doping to increase the conductivity and the density of active sites of CoO nanofibers, thus enhancing the electrocatalytic activity and stability. This work offers an efficient route to develop low-cost and highly active transitional metal oxide-based OER electrocatalyst for potential renewable electrochemical energy conversion and storage.
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
MICROPOROUS AND MESOPOROUS MATERIALS
·
2024
·
IF 4.8
Somboon Chaemchuen,Qing Wu,Jun-Fei Gu,Ye Yuan,Nikom Klomkliang,Francis Verpoort
The facile synthesis of composite material, combining magnetic CoO with ZIF-67 (CoO@ZIF-67), has been successfully developed. This innovative approach involves the growth of a crystalline (ZIF-67) derived from stable and abundant CoO, resulting in the formation of the composite magnetic CoO@ZIF-67. The synthesis method, based on a solid-state thermal approach (SST), is straightforward and efficient, conducted in a single step and under solvent-free conditions, leading to the homogeneously composite formation of CoO@ZIF-67. Importantly, the composite magnetic CoO@ZIF-67 material has demonstrated remarkable catalytic performance as a heterogeneous catalyst in various reactions while requiring a lower catalyst loading under comparable conditions to those needed for pure ZIF-67. A significant advantage of this newly developed composite catalyst, CoO@ZIF-67, is its ease of separation and recyclability. The recovery catalyst can be achieved through the use of an external magnet, making it a standout feature of the green and environmentally friendly synthetic procedure used in its production.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 10
·7606-7615
·
IF 2.22
Cai Haopeng,Wei Qinqin,Xiao Hongbo,Liu Hongwei,Wang Jun
The petal-like CoO/CNFs composites was synthesized in situ by a simple hydrothermal modus. Electromagnetic parameters of the CoO/CNFs composites are further adjusted by adjusting the weight fractional number of the CoO. A rich interface of CoO is introduced into the carbon nanofibers to form a flower-like composite. This unique flower-like layered structure and appropriate electromagnetic parameters effectively enhance the impedance matching and attenuation capabilities. When the mass ratio of CoO to CNFs is 2:1, the obtained flower-like CoO/CNFs composites achieves a maximum reflection loss of − 34.62 dB with a thickness of 3 mm at 7.8 GHz. At the same time, the effective absorption area is 2.89 GHz (7.035–9.925 GHz). Therefore, taking into consideration its excellent microwave absorption properties, the petal-like CoO/CNFs composites may be deemed as a high-efficiency absorbing agent that satisfies the impedance matching and attenuation characteristics.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Ji Ying Long,Zhi Shuo Yan,Yun Gong,Jian Hua Lin
Based on a meta-organic framework (MOF) formulated as [Co 4 (phen) 4 Cl 8 ] (phen = 1, 10-phenanthroline) as precursor, Cl/O doped C/CoO material (C/CoO-200) was synthesized by a one-step calcining method at a low temperature of 200 °C. In C/CoO-200, CoO nanoparticles with an average size of 25 nm were linked by carbon matrix into particles with the diameter of 200 nm ∼ 1 μm. The sample possessed a very low atomic percentage of CoO (CoO: 1.9%; C: 86.8%) due to the large amount of carbon from the organic ligand, phen in the precursor. However, it still exhibited a large specific capacitance of 1052 F g −1 at 0.5 A g −1 in 2 M KOH electrolyte with a 79.6% capacitance retention at 10 A g −1 . After successive etched in acid, Cl/O doped carbon nanoparticles were obtained. C-300 was composed by individual nanoparticles with size of 100–500 nm, it showed a specific capacitance of 207 and 164 F g −1 in 2 M KOH at a current density of 0.5 and 1 A g −1 , respectively, which was comparable to the commercial activated carbon (AC) (199 and 179 F g −1 for AC at 0.5 and 1 A g −1 , respectively). An asymmetric supercapacitor based on the positive electrode of C/CoO-200 and the negative electrode of C-300 exhibited a stable performance with a 61% retention of specific capacitance after 10,000 charging-discharging cycles at 1.5 A g −1 .
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2022
·Vol. 95
·期 2
·S352
·
IF 0.791
Meng Ying,Lu Shibin,Wu Yaodong,Sun Miao,Lu Haisheng,Zi Zhenfa,Sun Shengjie,Tang Hao
Abstract The porous CoO/MWCNTs and Zn/MWCNTs composites have been fabricated with the wet chemical method and pyrolysis process. For the reason of good impedance matching characteristics, CoO/MWCNTs composites with highly porous structure and dielectric loss properties present exceedingly powerful absorption ability of EM waves, which has a –44.67 dB maximum reflection loss (RL) value at 17.76 GHz at 1.5 mm sample thickness, and the absorption bandwidth below –10 dB is 14.0 GHz (4.0–18 GHz). Moreover, the filling content of the composites into paraffin matrix is merely 10 wt %, which is lower than that of most wave absorbers reported in the past. Consequently, CoO/MWCNTs composites can be used as a potentially lightweight EM wave absorbing material.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
NPG Asia Materials
·
2019
·Vol. 11
·期 1
·1-12
·
IF 8.052
Su Danni,Zhang Xiaomeng,Wu Aiping,Yan Haijing,Liu Ziyi,Wang Lei,Tian Chungui,Fu Honggang
Driving the electrocatalytic hydrogen evolution reaction (HER) with solar-energy cells is considered a green and sustainable way to produce H 2 . Herein, CoO-Mo 2 N hollow heterojunctions were designed for effective HER based on the combined virtues of the hollow structure and heterojunctions. The hollow CoMoO 4 -Co(OH) 2 precursor was first synthesized via the reaction of Co 2+ from ZIF-67 with MoO 4 2− and OH − in a Na 2 MoO 4 solution. A series of experiments indicate the formation of the hollow Co-Mo-O precursor followed a mechanism analogous to the nanoscale “Kirkendall Effect”. After heating in NH 3 , the CoO-Mo 2 N hollow heterostructure was obtained. The Mo species in the precursor played an important role in maintaining the morphology under nitridation treatment. The hollow structure is favorable for contact and diffusion of electrolyte with (in) catalysts, while the CoO in CoO-Mo 2 N is favorable for the dissociation of water. Both promote the HER. Under optimized conditions, the hollow catalyst exhibited good HER performance with an overpotential of 65 mV at 10 mA cm −2 in 1 M KOH. The performance is better than that of many nonprecious metal-based catalysts. An electrolyzer composed of CoO-Mo 2 N heterojunctions as the cathode and NiFe-LDH as the anode can be driven by a solar cell to achieve effective overall water splitting. The adjudication of MOFs makes the route promising for the design of robust catalysts for advanced application.
研究领域:
材料科学
·
可再生能源
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2022
·
IF 13.599
Shuang Xiang,Lin Dong,Zhiqiang Wang,Xue Han,Yong Guo,Xiaohui Liu,Xue-Qing Gong,Yanqin Wang
The depolymerization and upgrading of lignin from raw biomass, while keeping cellulose intact is important in biorefinery and various metal-based catalysts have been used in reductive catalytic fractionation, a key method in “lignin-first” strategy. Recently, we found that a core–shell structured Co@CoO catalyst with CoO shell as the real active site had excellent performance in the hydrogenolysis of 5-hydromethylfurfural to 2,5-dimethylfuran due to its unique ability to dissociate H 2 and yield active H δ− species (Xiang et al., 2022). In this work, we report a one-pot depolymerization and upgrading of lignocellulose to alkylcyclohexanols, a flavour precursor, with intact cellulose over this unique core–shell structured catalyst, Co@CoO. Lignin model compounds (β-O-4, 4-O-5, α-O-4) were first used to clarify the activity of Co@CoO catalyst. Then, the one-pot conversion of various organosolv lignin (birch, pine and poplar) to alkylcyclohexanols was realized with the mass yield of alkylcyclohexanols up to 25.8 wt% from birch lignin under the reaction condition of 210 °C, 1 MPa H 2 , 16 h. Finally, the corresponding woody sawdusts were used as feedstocks and found that the Co@CoO catalyst indeed preferentially depolymerized and upgraded the lignin part and obtained the same alkylcyclohexanols products with the retention of cellulose-rich pulp. The collected alkylcyclohexanols were further esterified to obtain value-added esters, which can be used as flavors. This work will inspire the design of new efficient metal oxide catalysts in lignin fractionation and depolymerization to high-value-added chemicals with intact cellulose.
研究领域:
生物化学
·
催化化学
·
可再生资源利用
✓ 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）