Journal of Materials Chemistry A
·
2016
·Vol. 4
·期 42
·16661-16669
·
IF 8.262
Shuo Li,Qidong Zhao,Dedong Meng,Dejun Wang,Tengfeng Xie
Cocatalysts are one essential factor for promoting the photoelectrochemical water oxidation efficiency of photoanodes, but the influence of interface charge transfer between the semiconductor and cocatalyst has been rarely addressed. Due to their poor charge conductivity, the application of many metal oxides as cocatalysts has been limited. In this work, using photoanode Ti/Fe2O3 and cocatalyst CoOx as a model system, we elaborately design a charge transfer channel of metal Co between the photoanode and cocatalyst. Such a ternary nanostructure has proved to possess several advantageous features, including effective charge separation efficiency, long lifetime of photogenerated holes, and fast charge transport from the photoanode to the surface of the cocatalyst. Benefiting from these desirable nanostructures, the photoanode, containing a charge transfer channel of metal Co, exhibited a remarkable photoelectrochemical performance for water oxidation, with an almost 7-fold enhancement in the photocurrent density at 1.23 V vs. RHE under visible light illumination and about a 0.15 V water oxidation onset potential negative shift compared to the Ti/Fe2O3 photoanode. These findings demonstrate that the successful construction of a metallic charge transfer channel between the photoanode and cocatalyst should be employed as a general strategy for photoconversion applications.
研究领域:
材料科学
·
光电化学
·
可再生能源
·
纳米材料
·
催化
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DOI
高影响因子
GREEN CHEMISTRY
·
2024
·
IF 9.3
Jie Li,Pengpeng Shao,Weijie Geng,Peng Lei,Jing Dong,Yingnan Chi,Changwen Hu
The oxidative depolymerization of β-O-4 linkages into value-added aromatic chemicals is of great importance for lignin valorization. However, achieving highly selective and rapid cleavage of β-O-4 linkages under mild conditions remains a challenge. Herein, cobalt–cobalt oxides (Co-CoOx) supported on N-doped carbon (CoMA/C900) combined with a green and recyclable base K7HNb6O19 (KNb6) have shown remarkable activity for the one-step oxidative cleavage of lignin β-O-4 linkages. Under relatively mild conditions (100 °C, 0.2 MPa O2), a lignin β-O-4 alcohol model compound was almost completely converted within 3 h, affording a narrow product distribution of phenol (yield: 99%) and methyl benzoate (yield: 98%). Based on the control experiments, kinetic study, and spectroscopic analysis, a synergistic oxidative cleavage mechanism was proposed: CoMA/C900 activates molecular oxygen to form a superoxide radical, while basic KNb6 promotes deprotonation of secondary alcohol, and they synergistically catalyze the oxidation of β-O-4 alcohol and the rapid cleavage of Cβ–O and Cα–Cβ bonds. During the reaction, the oxidation of β-O-4 alcohol to β-O-4 ketone is the rate-determining step, while the cleavage of PP-one to phenol and methyl benzoate can be completed within 15 min. Moreover, the CoMA/C900–KNb6 catalyst is recyclable at least three times and highly active for the oxidative cleavages of other lignin models and organosolv birch lignin.
研究领域:
化学工程
·
材料科学
·
生物质转化
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产品关联
DOI
高影响因子
Electrocatalysis
·
2019
·Vol. 10
·期 3
·277-286
·
IF 2.311
Chen Xiaowen,Wang Si,Wang Yan,Yang Zheng,Liu Sa,Gao Jingxia,Su Ziqian,Zhu Ping,Zhao Xinsheng,Wang Guoxiang
One-dimension (1D) heteroatom-doped mesoporous carbon is a promising alternative catalyst for oxygen reduction reaction (ORR). This work reported a hybrid ORR electrocatalyst composed of Co/CoO x nanoparticles embedded in N-doped mesoporous carbon layer coated on carbon nanotubes (CNTs@Co–N–C). Owing to the 1D mesoporous architecture with abundant active sites, CNTs@Co–N–C hybrid showed superior ORR activity, high selectivity, and long-term durability. Moreover, as cathode catalyst for primary Zn–air battery, CNTs@Co–N–C also showed excellent performance comparable to Pt/C. Thus, this study can offer a good idea for preparing noble-metal-free electrocatalysts for energy applications.
A 1D hybrid electrocatalyst composed of Co/CoO x nanoparticles embedded in N-doped mesoporous carbon layer coated on carbon nanotubes (CNTs@Co–N–C) was prepared for efficient ORR.
研究领域:
材料科学
·
电化学
·
能量存储与转换
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2023
·Vol. 38
·期 6
·1255-1261
·
IF 1.6
Tan Shifeng,Tu Wenmao,Pan Hongfei,Zhang Haining
Catalysts consisting of Zeolite imidazolyl ester skeleton-67 (ZIF-67) and graphene oxide (GO) were fabricated through a solvothermal method, followed by etching ZIF-67 with oxygen-rich functional groups on GO in a reduction atmosphere at 400 °C. During this process, an open type of cobalt metal center was formed by the partial vaporization and oxidation of ZIF-67, further reducing to Co and partially combining with oxygen species to amorphous CoO x . Benefiting from the rich functional N, and metal/oxides active centers derived from the calcination process, the synthesized Co/CoO x @NSG-400 showed a low OER overpotential of 10 mA·cm −2 at 298 mV, and an ORR half-wave potential of 0.8 V, which demonstrated its excellent bifunctional catalytic activity. Such a controllable calcination strategy with high yields could be expected to pave the way for synthesizing low-cost and efficient bifunctional electrocatalysts.
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产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
·
2023
·Vol. 8
·期 8
·1981-1992
·
IF 3.9
Li Sun,Mengying Sun,Yuan Zhi,Hua Zhang,Yuejin Shan,Binlin Dou,Jian Chen,Lixin Zhang
The continuous-flow (C-F) reduction process has been limitedly applied in the treatment of dyeing wastewater owing to the weak catalytic performance of the reactors employed. In this work, a small tubular packed reactor and its module are designed, fabricated and used for the C-F reduction of nitro and azo compounds in dyeing wastewater. Here, Au–Co–CoOx-coated glass beads with superior catalytic activity are chosen as packing materials, prepared without any toxic chemical agents. By means of the reactor, 4-nitrophenol (4-NP) can be completely removed and its removal rate is determined to be 100 μmol h−1. After that, a novel strategy for the tandem module is proposed to further enhance the removal rate of 4-NP. Based on the tandem module, the removal rate of 4-NP can be dramatically boosted to 1900 μmol h−1. Meanwhile, the rate constant for the C-F reduction of 4-NP can reach up to 0.44 s−1. Furthermore, the tandem module displays satisfactory operating stability, reusability and reliability in real water samples. In addition, the tandem module first achieves the C-F reduction of 2-nitrophenol, 3-nitrophenol, methyl red and methyl orange. Clearly, the reactor and its module can effectively extend the application of the C-F reduction process in dyeing wastewater treatment.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Lin Zhong,Hu Zhou,Ruifeng Li,Hao Cheng,Sheng Wang,Boyuan Chen,Yongyue Zhuang,Junfeng Chen,Aihua Yuan
Developing highly efficient oxygen electrocatalysts is of vital importance for rechargeable Zn-air batteries (ZABs). Herein, Co/CoO x nano-heterojunctions encapsulated into nitrogen-doped carbon sheets (NCS@Co/CoO x ) are fabricated via a dual-template-guided approach by using zeolitic imidazolate frameworks (ZIFs) as templates. The synergistic integration of structural and compositional advantages endows such catalyst with superior catalytic properties to benchmark noble-metal catalysts. To be specific, the hierarchical micro/mesopores affords massive mass transport channels and maximizes the exposure of accessible active sites, whereas the NCS matrix accelerates electron transfer and prevents the self-aggregation of active species during the electrocatalytic reaction. Moreover, abundant and synergistic Co-based active sites (CoO, Co 3 O 4 , Co-N x ) greatly promote the catalytic activity. As the cathode of both liquid and flexible solid-state ZABs, excellent device properties are achieved, outperforming those assembled with commercial Pt/C+RuO 2 catalyst. This work presents a feasible and cost-effective strategy for developing oxygen electrocatalysts derived from ZIFs templates.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Sa Liu,Xiaowen Chen,Si Wang,Zheng Yang,Jingxia Gao,Ping Zhu,Xinsheng Zhao,Guoxiang Wang
Developing an efficient non-precious metal catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in regenerative energy conversion and storage devices is very imperative but still challenging. Herein, a three-dimensional (3D) hierarchical porous Co/CoO x nanoparticles embedded N-doped carbon hybrid threaded with carbon nanotubes (Co/CoO x @NC-CNTs) was prepared via in situ threading CNTs through ZIF-67 polyhedron and a succedent carbonation process. Compared to those of commercial electrocatalysts (Pt/C and RuO 2 ), the as-prepared hybrid showed comparable electrocatalytic activity with positive ORR half-wave potential ( E 1/2 ) of 0.836 V, low OER potential ( E j=10 = 1.62 V), good methanol tolerance and excellent electrocatalytic stability. Moreover, the small overpotential difference value (Δ E = E j=10 - E 1/2 ) of 0.784 V is competitive to those of recent reported outstanding bifunctional oxygen electrocatalysts. The high electrocatalytic properties of the Co/CoO x @NC-CNTs hybrid are attributed to the synergistic effect of high surface area, desirable pore structure and reasonable chemical composition .
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
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2025
·
IF 4.7
Yinming Fan,Yuanzhen Li,Siqi Jiang,Yanping Zhang,Yinian Zhu,Shengpeng Mo,Lei Liao,Yanan Zhang,Xiaobin Zhou,Zongqiang Zhu
Volatile organic pollutants (VOCs) can serve as an alternative to ammonia for NO reduction, thereby enabling the simultaneous removal of VOCs and NO. In this study, different morphologies of MnO x /CoO x catalysts derived from MOFs were controllably synthesized under various hydrothermal synthesis conditions for the simultaneous removal of 1,2-propanediol and NO. Among the various samples, sample A, characterized by its rod-like structure, demonstrated superior catalytic activity. It achieved simultaneous photothermal coupling for the degradation of 1,2-propanediol and NO under UV irradiation at 240 °C, with conversion rates reaching 52 % and 67 %, respectively. The morphology of the catalysts significantly influences their catalytic performance. The incorporation of Mn increased the structural disorder of the material, thereby reducing the coordination order of Co. This significant change in the coordination environment modulates the intrinsic catalytic activity of the samples, leading to distinct catalytic properties. Furthermore, the catalytic reaction mechanisms were clarified utilizing in-situ DRIFTS combined with calculations based on Density Functional Theory. Sample A, featuring abundant unsaturated cobalt and manganese defects within its distinctive coordination configuration, greatly promoted the conversion of 1,2-propanediol into crucial intermediate species. This study presents a novel approach for the synergistic removal of VOCs and NO x .
研究领域:
催化化学
·
材料科学
·
环境化学
·
纳米材料
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Danfeng Xiao,Huihui Li,Hengtao Fu,Xiaofei Chen,Zelong Li,Yuhua Wang
Developing acid-tolerant photocatalysts for efficient water oxidation in unmodified Fe3+ redox media is pivotal for realizing solar energy storage via the “hydrogen farm” strategy, yet remains challenging due to intrinsic charge recombination and corrosion issues. Here, we introduce a nitrogen-doped hexagonal/tetragonal BaTa2O6 heterophase photocatalyst decorated with spatially separated Pt and CoOx cocatalysts for stable oxygen evolution in acidic Fe(NO3)3 solutions (pH 1.8). The heterophase junction, corroborated by high-resolution transmission electron microscopy (HRTEM), creates a directional built-in electric field (evidenced by surface photovoltage spectroscopy) that minimizes interfacial energy loss (<0.2 eV, confirmed by density functional theory calculations). Selective photodeposition of Pt at particle termini and CoOx on lateral surfaces spatially decouples Fe3+ reduction and water oxidation half-reactions, effectively suppressing charge recombination. Enabled by nitrogen doping-induced bandgap narrowing (light absorption up to 630 nm), the optimized catalyst achieves an unprecedented O2 evolution rate of 124 μmol h−1 under visible light, with apparent quantum efficiencies of 10.5% at 420 nm and 0.3% at 600 nm. The system maintains over 93% activity for 12 h and demonstrates robust compatibility with Fe2+/Fe3+ redox cycling, confirmed by the stoichiometric production of H2/O2 (2 : 1) in a Z-scheme overall water splitting configuration. This work establishes a novel heterophase engineering approach for designing acid-stable photocatalysts, offering a promising pathway toward practical solar-to-chemical energy conversion.
研究领域:
光催化
·
能源化学
·
材料科学
·
表面科学
·
可持续能源
·
半导体物理
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Xianghan Cheng,Yalin Liu,Man Yang,Xiaoli Wang,Aili Wang,Zhen Li,Zhongmin Liu,Yong-Zheng Zhang,Xiuling Zhang,Da-Shuai Zhang,Shujuan Zhuang,Longlong Geng
Developing metal oxide catalysts with comparable activity to precious metals has become a hot but challenging area of research for wastewater purification. Herein, CoO x particles and nitrogen co-doped carbon with a hierarchical structure were designed and synthesized via a temperature-controlled pyrolysis strategy using inert Co-based metal–organic frameworks (Co-MOFs) as precursors. Unlike traditional methods, the exquisite pyrolysis of the Co-MOF at 400 °C enabling the CoO x particles with an average diameter of 6.8 nm to uniformly disperse, thus facilitating the formation of the optimized CoO x /CN-400 composite. Benefiting from the unique morphology and composition, CoO x /CN-400 exhibited improved redox property and exceptional activity for the reduction of nitrophenol to form the corresponding aminophenol compounds. The complete conversion of 4-nitrophenol over CoO x /CN-400 requires only 35 min with a rate constant of 0.12 min −1 , which is significantly higher than that of most non-noble metal catalysts and approaching some of the noble metal-based catalysts. Furthermore, leveraging the embedded CoO x particles, CoO x /CN-400 maintains its high catalytic efficiency even after six successive cycles, demonstrates an outstanding long-term catalytic capability and reusability. Finally, the mechanisms of 4-NP reduction have been hypothesized based on the combination of characterization and DTF calculations.
研究领域:
材料科学
·
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Zhuang Wang,Mian Li,Wenping Cao,Xiangjie Bo
Enhancing catalytic efficiency, achieving controlled synthesis, and lowering production costs are crucial for promoting the use of cobalt oxide (CoOx)/cobalt nitride (CoNx) composites in full water splitting and electrochemical sensing. In this study, a three-dimensional (3D) hierarchically porous material composed of numerous two-dimensional (2D) porous CoOx/CoNx nanosheets (denoted as CoOx/CoNx NSs) was synthesized by using cobalt oxalates (COs) recycled from spent lithium-ion batteries. In a 1.0 M KOH solution, the 2D porous CoOx/CoNx NSs exhibited higher oxygen evolution reaction (OER) electrocatalytic activity than commercial ruthenium oxide (RuO2). Meanwhile, the CoOx/CoNx NSs exhibited a slightly lower hydrogen evolution reaction (HER) electrocatalytic activity than 20 wt % platinum/carbon (Pt/C). Moreover, the CoOx/CoNx NS-based full water-splitting electrolyzer achieved a current density of 10 mA cm–2 at 1.562 V, which was 49 mV more positive than the 1.489 V of the Pt/C||RuO2 benchmark. Furthermore, the 2D porous CoOx/CoNx NSs featured significantly higher HER, OER, and full water-splitting catalytic stability than Pt/C/RuO2. Moreover, the CoOx/CoNx NS-based nonenzymatic electrochemical sensor exhibited advanced glucose detection performance. Particularly, the sensor had a wide linear range of 1.0–10.5 mM), a low detection limit of 5.0 μM), and a fast response time of 0.6 s. The 2D porous CoOx/CoNx NSs exhibited excellent catalytic activity owing to their 3D hierarchically porous architectures, large surface area, good conductivity, uniformly dispersed active sites, and synergistic effects of CoNx and CoO. This study presents an advanced model for recycling Co metal from spent devices and designing advanced Co-based electrocatalysts for water splitting and electrochemical sensing.
研究领域:
材料科学
·
环境科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Meiling Liu,Liping Wang,Qilong Fan,Ningning Xiao,Zhiwen Chen,Yingying Dong,Chuanliang Zhao,Yongxia Sun,Xing Xu,Wendong Wang
Nitrogen (N)-doping has been reported effective to reinforce catalysis in advanced oxidation processes (AOPs) due to the formation of N-related active sites. Although several documents have reported that transition metal-nitrogen (metal-N x ) sites could work as reactive centers, the catalytic mechanism was hardly elucidated. In this study, N-doped cobalt oxide (N-CoO x ) was initiatively prepared via calcination in ammonia atmosphere to construct cobalt-nitrogen (Co-N x ) sites. The emergence of Co-N x sites effectively improved peroxymonosulfate (PMS) activation efficiency (above 5.8 times), leading to higher pollutant decomposition rate (95.8 % at 30 min) and kinetics constant (above 4.1 times). N introduction changed main facets of material and elevated adsorption energy (E ads ) (from −1.81 eV to −3.71 eV) between catalyst and PMS. Co atoms at Co-N x sites could donate larger quantity of electrons (from 1.088 e to 1.583 e) to PMS, therefore, contributed to stretching and breaking O–O bonds of PMS molecules to form reactive species. As a result, both radical and electron transfer pathway (ETP) were enhanced in the oxidation processes. Ultimately, the catalytic membrane coated with N-CoO x maintained 100 % treatment towards continuous antibiotic wastewater at environmentally relevant concentration (μg/L), realizing purification as well as separation of catalyst. This work systematically elaborates the superiority of Co-N x sites and unravels the underlying mechanism to inspire further study to metal-N x tailored catalysis.
研究领域:
环境科学
·
催化
·
材料科学
·
水处理
✓ 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）