INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Jin Song,Fenglong Wu,Yulun Lu,Xinyan Zhang
Doping as a common mean to generate defects to boost the catalytic performance of metal oxide semiconductor-based materials has aroused great interest. However, doping usually requires high temperatures and is time consuming. Herein, we report a facile strategy for the preparation of F doped CeO 2 (F–CeO 2 ) with assistance of the electrostatic attraction between F − and CeO 2 with oxygen vacancies at room temperature , then F–CeO 2 acts as superior support of metal Co nanoparticles (NPs) for efficient hydrolysis of NH 3 BH 3 under light irradiation . The activity of Co/F–CeO 2 is significantly enhanced and Co/F–CeO 2 -0.6 exhibited highest catalytic activity with TOF value 92.8 min −1 which increases 47% compared with Co/CeO 2 . Experimental and characterization results show the enhanced performance attributes to high efficiency photogenerated carrier separation and boosting adsorption capacity of H 2 O and NH 3 BH 3 over Co/F–CeO 2 due to F doped into CeO 2 crystallites . Furthermore, theory calculations further confirm that the band gap of F–CeO 2 becomes smaller and F–CeO 2 is more favorable the adsorption for H 2 O and NH 3 BH 3 than pure CeO 2 . This work offers a facile and time efficiency strategy to realize controllable element doped in metal oxide under ambient, and gives deep insights into the structure–activity relationship of catalyst between defect engineering and photocatalytic performance.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Zhanhe Liu,Zirui Liu,Kechao Zhou,Zihang Chen,Kaihua Shi,Xinyu Wang,Chaoqun Peng,Richu Wang,Shlomo Magdassi,Jin He,Xiaofeng Wang
The additive manufacturing of hardmetals has attracted great attention recently but faces significant challenges in low printing resolution and low mechanical strength. Herein, the fabrication of hardmetal parts with complex structures and high surface quality by vat photopolymerization assisted with a sintering process has been achieved. This was enabled by in situ polymerization-induced microencapsulation of WC powder, which simultaneously enhances the photocuring ability and sedimentation stability of the WC-Co slurry. The WC powder is microencapsulated by a polystyrene (PS, WC@PS) coating with a thickness of ∼20 nm. The curing depth of the WC-Co slurry with WC@PS was dramatically increased from 32 to 336 μm compared to the slurry with original WC, exhibiting an average increment of 650%. The 3D-printed hardmetal parts exhibited a relative density of 99.5%, a Rockwell hardness of 86.9 HRA, and a surface roughness Ra of 2.26 μm, approaching the theoretical limits in classical powder metallurgy-derived WC-Co hardmetal parts. With high density and hardness, it is shown that a printed drilling bit can easily drill through metal sheets. This work paves a path for the vat photopolymerization 3D printing of miniature complex hardmetal components combined with high surface quality and high performance.
研究领域:
材料科学
·
增材制造
·
表面工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2018
·
IF 6.14
Lanhua Yi,Fujun Lan,Jinge Li,Caixian Zhao
Photocatalytic water splitting for H2 evolution is appealing for transforming solar energy into clean chemical fuel. This technique generally requires noble metals as H2 evolution cocatalysts to facilitate efficient cleavage of water. Herein, we report a noble-metal-free TiO2 nanobelts composite photocatalyst, in which TiO2 nanobelts are supported by nitrogen-doped graphene coordinated with a single Co atom (Co-NG). The results show that Co-NG is an efficient cocatalytst for the photocatalytic H2 production over TiO2. The optimal amount of Co-NG loading is found to be 3.5 wt %, showing a H2 evolution rate of 677.44 μmol h–1 g–1 under illumination of AM 1.5 G simulated sunlight, which is close to that of platinized TiO2 nanobelts and 2.6 and 31.2 times greater than that of 3.5 wt % NG/TiO2 nanobelts composite and pure TiO2 nanobelts, respectively. The significantly improved photocatalytic activity is ascribed to the remarkable synergistic effect between single-atom Co and N-doped graphene, which serve as effective H+ reduction sites and efficient electron acceptors, respectively. Besides, the Co-NG cocatalyst also effectively retards the recombination of photoinduced charge carriers and leads to a prolonged lifetime of charge pairs. This study reveals that Co-NG is an up-and-coming candidate as cocatalyst for development of cost-effective photocatalysts for efficient solar-driven H2 evolution.
研究领域:
材料科学
·
可再生能源
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Wujian Zhang,Weijian Ge,Yiping Jin,Mingming Dang,Panpan Zhang,Wenfeng Han,Ying Li,Zongjian Liu,Haodong Tang
Loaded noble metal redispersion is an important way to solve catalyst sintering. However, how to redisperse at low temperatures or carbon-based noble catalysts is a difficult problem. In this paper, we report this phenomenon occurring on PdCu alloy catalysts, where small-sized PdCu alloys can be realized from sintered large-sized PdCu alloys on carbon supports in a CO/O 2 atmosphere. The mechanism of redispersion is elucidated by XPS, TEM and DFT calculations. The main reason for the redispersion is the formation of the PdCuOx intermediate, which can easily migrate to the nearby catalyst surface and then be reduced to smaller PdCu alloy nanoparticles. This work provides a deeper understanding of the redispersion phenomenon and provides certain applications in industry.
研究领域:
催化
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Muhammad Sabir,Mahmoud Sayed,Zhuofan Zeng,Bei Cheng,Wang Wang,Chuanbin Wang,Jingsan Xu,Shaowen Cao
The photocatalytic conversion of carbon dioxide (CO 2 ) into valuable products holds great promise from environmental and economic perspectives. However, current photocatalytic materials still exhibit unsatisfactory efficiency. In this study, a notably efficient step-scheme (S-scheme) heterojunction was developed by combining the Co-MOFs with carbon nitride nanosheets (g-C 3 N 4 ). The electrostatic interaction between these components not only facilitates the exfoliation of g-C 3 N 4 layers but also enhances the stability of the photocatalyst structure. The optimal heterojunction Co-CN4 photocatalyst achieved a significantly enhanced CO production rate of 16.1 µmol g −1 h −1 , which is 4.7 times higher than that of pure g-C 3 N 4 . This improved activity is ascribed to the enhanced light absorption and mitigated charge carrier recombination. Density functional theory (DFT) computations in conjunction with experimental observations elucidate the establishment of a close contact interface. Additionally, electron paramagnetic resonance (EPR) and in situ X-ray photoelectron spectroscopy (XPS) characterization unveil the electron transfer pathway of Co-CN4 during photocatalytic CO 2 conversion. This study offers valuable insights into the design of S-scheme photocatalysts for enhancement of CO 2 photoreduction.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Green Processing and Synthesis
·
2025
·Vol. 14
·期 1
·
IF 3
Fuhua Wei,Yan Wang,Qinhui Ren,Qin Zhang,Hongliang Chen,Zhao Liang
Cr/Co-MOFs were synthesized via a solvothermal method using chromium acetate and cobalt chloride hexahydrate as metal ions, and trimeric acid as the organic ligand. The structures of Cr/Co-MOFs were characterized using Fourier infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques. These Cr/Co-MOFs were used for removing organic contaminants in wastewater treatment. Fleroxacin and Rhodamine B (RhB) were specifically selected as target molecules in this study to evaluate the removal efficiency based on the mass of Co/Cr-MOFs, concentrations of organic contaminants, and adsorption time. Experimental findings indicated that at a Co/Cr-MOFs dosage of 100 mg, with initial concentrations of Fleroxacin (30 ppm) and RhB (20 ppm), removal efficiencies achieved were 95% and 99%, respectively. Within a timeframe of 5 h, Co/Cr-MOFs attained adsorption capacities amounting to 269.6 mg·g −1 for fleroxacin and 289.5 mg·g −1 for RhB. The interaction between Co/Cr-MOFs and fleroxacin, as well as RhB, is primarily attributed to factors such as pore size, hydrogen bonding, electrostatic charge, and π–π interactions. Moreover, theoretical analysis corroborated these experimental results by demonstrating conformity between the adsorption process and both second-order kinetic model equations alongside Langmuir isotherm model equations. Collectively, the experimental data combined with theoretical investigations underscore the practical significance associated with employing Co/Cr-MOFs for effective eradication of organic pollutants.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Dongyan Shen,Yong Liu,Guangxing Yang,Hao Yu,Peng-Fei Liu,Feng Peng
The electrooxidation of carbon monoxide is a typical example of structure sensitivity in electrocatalysis for fuel cells. Understanding the structure sensitivity is crucial in designing highly efficient catalysts and elucidating reaction mechanisms. Conventionally, only the reactivity of active sites was considered and optimized. However, how the reactant chemically moves to the active site has not been well studied. In this work, we found that CO ad hopping is a general phenomenon on noble metal surfaces such as platinum, iridium, rhodium, and palladium in the case of CO monolayer electrooxidation. Differences in the performances of CO ad stripping on platinum nanoparticles with different surface structures reveal that the CO ad hopping rate is structure sensitive as well. Assisted by a diffusion modeling and density functional theory calculations, it is demonstrated that the structure sensitivity is as a result of a compromise between CO ad chemical diffusivity and reactivity with OH ad .
研究领域:
材料科学
·
电化学
·
理论计算
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Yihui Li,Ziang Zhao,Min Zhao,Hejun Zhu,Xinzheng Ma,Zheng Li,Wei Lu,Xingkun Chen,Linbin Ying,Ronghe Lin,Yu Meng,Yuan Lyu,Li Yan,Yunjie Ding
Promotional effects of oxygen vacancies of spinel catalysts in CO 2 hydrogenation are reported in early works, but the mechanistic origins remain elusive. Here, CoAl 2 O 4 spinels with varying numbers of oxygen vacancies are deliberately designed by a sol-gel method and different post-treatments. By combining catalytic testing, advanced electron microscopic and spectroscopic characterizations, and computational studies, the unusual oxygen vacancy-dependent catalytic behaviors are rationalized. Our work reveals that i) perfect spinel crystals possessing least oxygen vacancies can effectively constrain the Co 2+ species at working conditions that are less active but selective to CO; and ii) vacancy-rich spinels promote both H 2 and CO 2 activations and COOH* formation, explaining the higher hydrogenation activity, but overwhelming vacancies cause Co 2+ reduction and promote direct CO 2 * dissociation to CO* and deep hydrogenation to CH 4 . These molecular-level understandings reinforce the idea of proper design of oxygen vacancies to achieve activity-selectivity balance.
研究领域:
材料科学
·
催化化学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2016
·
IF 3.997
Yuhua Yan,Yanping Tian,Meifeng Hao,Yuqing Miao
The cross-like crystallines of Ni-Co-P microcomposites were synthesized via a simple hydrothermal method under high pressure and temperature which is adapted from the classical electroless deposition technique for surface modification. Here hypophosphite was employed as reductant and phosphorus resource to prepare the composites of Ni, Co and P elements. The obtain Ni-Co-P microcomposites were characterized in morphology, composition and properties. They show the perfect cross-like shape with an approximate stoichiometry of Ni 12 -Co 6 -P 12 -O 70 . The high absorbance in UV area and wide absorbance in vis area are observed. They also exhibit superparamagnetic behavior and hydrogen evolution property.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2018
·
IF 11.384
Shuai Lyu,Li Wang,Jianghao Zhang,Chen Liu,Junming Sun,Bo Peng,Yong Wang,Kenneth G. Rappé,Yuhua Zhang,Jinlin Li,Lei Nie
In order to understand the role of Co catalysts with different phases on Fischer–Tropsch synthesis, single-phase face-centered-cubic (fcc) and hexagonal-close-packed (hcp) Co were synthesized via a two-step approach, involving the formation of single-phase CoO materials followed by reduction in H2. The physicochemical properties of Co catalysts were thoroughly characterized by XRD, SEM, TEM, TPR, and H2 chemisorption. It was found that hcp-Co exhibits higher activity on hydrocarbon formation than fcc-Co in Fischer–Tropsch synthesis. For both catalysts, CO dissociation was suggested as the rate-determining step, on which hcp-Co presents ca. 40 kJ mol–1 lower activation energy than fcc-Co, in agreement with a reported computational study. As a result, hcp-Co is concluded to be the preferable phase for rational catalyst design.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 119
·98500-98507
·
IF 3.84
Yunshi Liu,Ping Yang,Jia Li,Katarzyna Matras-Postolek,Yunlong Yue,Baibiao Huang
SnO2 and SnO2/CeO2 one dimensional (1D) nanostructures with various morphologies including solid nanofibers (NFs), nanobelts (NBs), nanotubes (NTs), and wire-in-tubes (WTs) were successfully prepared via a single-spinneret electrospinning process and a subsequent heat-treatment by adjusting the heating rate and the amount of CeO2. The interesting morphology evolution of samples from NTs to NBs was reported with increasing amounts of CeO2. In addition, SnO2 particles existed on the surface of the CeO2 matrix to form diverse structures in the 1D nanofibers. The band gap of the composite oxides decreased with the addition of CeO2. Compared with other nanostructures, SnO2/CeO2 NTs exhibited superior gas sensing properties, such as the highest response to ethanol. Due to the existence of Ce3+ and oxygen vacancies and the hollow structure, SnO2/CeO2 NTs revealed great CO oxidation performance, indicating the enhanced interactions between the catalyst and the target gas. These excellent properties were attributed to the prominent 1D hollow morphology, the good dispersion of SnO2 nanoparticles on the surface of the CeO2 matrix, the ideal crystallinity, and the composite interactions between the two oxides. In addition, the current method could be utilizable to fabricate other metal oxides with various morphologies for property controlling and important applications.
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Shizhu Song,Tian Qin,Qi Li,Yanqing Wang,Yanfeng Tang,Lifang Zhang,Xiaojuan Liu
Facile synthesis of cost-effective carbon-supported Co single atoms (Co-SAs) exhibits huge potential applications in energy storage and conversion devices. We here report the implantation of Co-SAs into hollow carbon spheres (Co-SAs-HCS) via a facile wet-chemistry strategy followed by controlled pyrolysis. Electron-rich histidine acted as a Lewis base effectively immobilizing Co2+ (Lewis acid) via the electrostatic effect and hydrogen bonds, thus achieving the scalable synthesis of Co-SAs-HCS. We constructed a series of histidine-Co2+ structure models to elucidate the formation of histidine-Co2+ complexes by analyzing their binding energy. X-ray absorption fine-structure results verify that central Co atoms with four N coordination atoms possess a non-planar Co-N4 structure. Electrochemical results indicate that the as-prepared Co-SAs-HCS catalyst shows a low potential difference (0.809 V) between the oxygen evolution reaction potential at 10 mA cm–2 and the oxygen reduction reaction half-wave potential, outperforming the commercial Pt/C catalysts (0.996 V). Moreover, an assembled Zn-air battery based on Co-SAs-HCS exhibits an unexpected long-term durability. We have demonstrated that non-planar Co-N4-1-O2 sites are the source for highly efficient adsorption and dissociation of O2 molecules and then reduction of the free energy of desorption of the intermediates by density functional theory. Our findings provide a new design insight into the exploration of advanced electrocatalysts, which will be applied in the design of green energy devices in the future.
研究领域:
材料科学
·
电化学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）