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A Catalytic Copper/Cobalt Oxide Interface for Efficient Hydrogen Generation

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Energy & Environmental Materials 2023年第2期6卷 1-7页

作者： Wenjing Xu Sheli Zhang Ruofan Shen Zhikun Peng Baozhong liu Jun li Zhanying Zhang baojun li School of Science Jiaozuo Engineering Technology Research Center of Separation and Adsorption MaterialsJiaozuo Teachers CollegeJiaozuo Henan 454000China Research Center of Green Catalysis College of ChemistryZhengzhou UniversityZhengzhou 450001China School of Materials Science and Engineering Henan Polytechnic UniversityJiaozuo 454000China

Metal nanoparticles and metal oxides promisingly provide different catalytic active sites at their interfaces.Constructing high-density interfaces is essential to maximize synergies.Herein,a Cu-Co_(3)O_(4) nanoparticles interfacial structure produced via pyrolysis and moderate oxidation from metal-organic frameworks has been designed to boost the intrinsic activity.The Cu-Co_(3)O_(4) nanoparticles composites exhibit a turnover frequency of 57.5 min−1 for ammonia borane hydrolysis,far higher than those of monometallic Cu and Co_(3)O_(4) nanoparticles,showing the synergistic effect of Cu and Co_(3)O_(4) nanoparticles at their interface.Density functional theory calculations and in situ Raman spectroscopy reveal the catalytic mechanism of dual active sites,in which Co_(3)O_(4) nanoparticles at Cu-Co_(3)O_(4) interface efficiently bind and activate water molecules and Cu nanoparticles easily activate NH3BH3 molecules.This study opens up a new pathway for achieving high-efficiency noble metal-free catalysts for hydrogen generation and other heterogeneous catalysis.

关键词： ammonia borane metal metal oxide metal-organic framework synergistic effect

light-induced thermal convection for collection and removal of carbon nanotubes

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Fundamental Research 2022年第1期2卷 59-65页

作者： Xianguang Yang Rui Xu Long Wen Zaizhu Lou Qin Chen baojun li Institute of Nanophotonics Jinan UniversityGuangzhou 511443China

Carbon nanotubes(CNTs)have exhibited immense potential for applications in biology and medicine,and once their intended purpose is fulfilled,the elimination of residual CNTs is essential to avoid negative effects.In this study,we demonstrated the effective collection and simple removal of CNTs dispersed in a suspension via thermal convection.First,a tapered fiber tip with a cone angle and end diameter of 10°and 3μm,respectively,was fabricated via a heating and pulling method.Further,a laser beam with a power and wavelength of 100 mW and 1.55^m,respectively,was launched into the tapered fiber tip,which was placed in a CNT suspension,resulting in the formation of a microbubble on the fiber tip.The temperature gradient on the microbubble and suspension surface induced thermal convection in the suspension,which resulted in the accumulation of CNTs on the fiber tip.The experimentally formed CNT cluster possessed a circular top surface with a diameter of 87 nm and an arched cross-section with a height of 19μm.Furthermore,this CNT cluster was firmly attached to the fiber tip.Therefore,the removal of CNT clusters can be realized by simply removing the fiber tip from the suspension.Moreover,we simulated the thermal convection that caused CNT aggregation.The obtained results indicate that convection near the fiber tip flows toward it,which pushes the CNTs toward the fiber tip and enables their attachment to it.Further,the flow velocity is symmetrically distributed as a Gaussian function,which results in the formation of a circular top surface and arched cross-sectional profile for the CNT cluster.Our method may be applied in biomedicine for the collection and removal of nano-drug residues.

关键词： Convection Microbubble Aggregation Morphology Carbon nanotubes Surface tension

Polar O-Co-P Surface for Bimolecular Activation in Catalytic Hydrogen Generation

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Energy & Environmental Materials 2023年第1期6卷 224-233页

作者： Huanhuan Zhang Ke Zhang Saima Ashraf Yanping Fan Shuyan Guan Xianli Wu Yushan liu Baozhong liu baojun li Research Center of Green Catalysis College of ChemistryZhengzhou University100 Science RoadZhengzhou 450001China College of Chemistry and Chemical Engineering Henan Polytechnic University2001 Century AvenueJiaozuo 454000China

Boron hydrides release an abundant amount of hydrogen in the presence of a suitable catalyst.Accelerating bimolecular activation kinetics is the key to designing cost-effective catalysts for borohydride hydrolysis.In this study,the bimolecular activation of a polar O-Co-P site demonstrated superior hydrogen-generation kinetics(turnover frequency,TOF=37 min−1,298 K)and low activation energy(41.0 kJ mol^(−1))close to that of noble-metal-based catalysts.Through a combination of experiments and theoretical calculations,it was revealed that the activated dangling oxygen atom in the Co–O precursor effectively replaced via surface-phosphorization because of strong electronic interactions between the dangling oxygen and P atoms.This substitution modulated the local coordination environment and electronegativity around the surface Co sites and formed a new polar O-Co-P active site for optimizing the activation kinetics of ammonia borane and water.This strategy based on bimolecular activation may create new avenues in the field of catalysis.

关键词： bimolecular activation borohydride hydrolysis hydrogen generation noble-metal-free catalysts polar site

Wood-derived integrated air electrode with Co-N sites for rechargeable zinc-air batteries

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Nano Research 2022年第2期15卷 1415-1423页

作者： Benji Zhou Yanyan liu Xianli Wu Huan liu Tao liu Yi Wang Sehrish Mehdi Jianchun Jiang baojun li Research Center of Green Catalysis College of ChemistryZhengzhou University100 Science RoadZhengzhou 450001China Institute of Chemical Industry of Forest Products CAFNational Engineering Lab for Biomass Chemical UtilizationNanjing 210042China College of Science Henan Agricultural UniversityZhengzhou 450002China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafery National Center for Nanoscience and TechnologyBeijing 100190China Department of Chemistry The Women UniversityKutchery CampusL.M.Q.RoadMultan 66000Pakistan

The sluggish reaction kinetics in oxygen reduction reaction(ORR)is one of the bottlenecks in next generation energy conversion systems.The integrated design strategy based on simultaneously constructing active sites and forming porous carbon network will address this concern by facilitating charge exchange,mass transfer and electron transportation.In this article,a three-dimensional integrated air electrode(Co-N@ACS)containing Co-N sites and hierarchically porous carbon is fabricated via growth of Co-doped ZIF-8 in activated wood substrate and synchronous pyrolysis.The optimized integrated air electrodes exhibit ultrahigh ORR activity(E_(1/2)=0.86 V).Co-N sites provide outstanding ORR activity,and hierarchically porous structures facilitate oxygen diffusion and electrolyte penetration.Aqueous zinc-air battery assembled with Co-N@ACS possesses open-circuit voltage of 1.46 V,peak power density of 155 mW cm^(-2) and long-term stability of 540 cycles(180 h).Solid-state zinc-air battery assembled with Co-N@ACS shows open-circuit voltage up to 1.36 V and low charge-discharge voltage gap(0.8 V).This design strategy paves the way for the conversion of wood biomass to integrated air electrodes and catalytically active carbon for next generation energy storage and conversion devices.

关键词： atomically dispersed Co integrated air electrode oxygen reduction reaction wood biomass zinc-air batteries

Co_(2)N Nanoparticles Anchored on N-Doped Active Carbon as Catalyst for Oxygen Reduction Reaction in Zinc–Air Battery

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Energy & Environmental Materials 2022年第3期5卷 935-943页

作者： Xianli Wu Guosheng Han Hao Wen Yanyan liu Lei Han Xingyu Cui Jiajing Kou baojun li Jianchun Jiang Research Center of Green Catalysis College of ChemistryZhengzhou University100 Science RoadZhengzhou 450001China National Engineering Laboratory for Biomass Chemical Utilization Institute of Chemical Industry of Forest ProductsChinese Academy of ForestryNanjing 210042China College of Science Henan Agricultural UniversityZhengzhou 450002China Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveIN 47906United States State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University28 Xianning West RoadXi'an 710049China

The development of efficient catalytic electrode toward oxygen reduction reaction(ORR)is still a great challenge for the wide use of zinc–air batteries.Herein,Co_(2)N nanoparticles(NPs)anchored on N-doped carbon from cattail were verified with excellent catalytic performances for ORR.The onset and half-wave potentials over the optimal catalyst reach to 0.96 V and 0.84 V,respectively.Current retention rates of 96.8%after 22-h test and 98.8%after running 1600 s were obtained in 1 M methanol solution.Density functional theory simulation proposes an apparently increased electronic states of Co_(2)N in N-doped carbon layer close to the Fermi level.Higher charge density,favorable adsorption,and charge transfer of intermediates originate from the coexistence of Co_(2)N NPs and N atoms in carbon skeleton.The superior catalytic activity of composites also was confirmed in zinc–air batteries.This novel catalytic property and controllable preparation approach of Co_(2)Ncarbon composites provide a promising avenue to fabricate metal-containing catalytically active carbon from biomass.

关键词： catalytically active carbon Co2N nanoparticles N-doping oxygen reduction reaction zinc–air battery

Fiber-based optical trapping and manipulation

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Frontiers of Optoelectronics 2019年第1期12卷 97-110页

作者： Hongbao XIN baojun li Institute of Nanophotonics Jinan UniversityGuangzhou 511443China

An optical fiber serves as a versatile tool for optical trapping and manipulation owing to its many advantages over conventional optical tweezers,including ease of fabrication,compact configurations,flexible manipulation capabilities,ease of integration,and wide applicability.Here,we review recent progress in fiberbased optical trapping and manipulation,which includes mainly photothermal-based and optical-force-based trapping and manipulation.We focus on five topics in our review of progress in this area: massive photothermal trapping and manipulation,evanescent-field-based trapping and manipulation,dual-fiber tweezers for singlenanoparticle trapping and manipulation,single-fiber tweezers for single-particle trapping and manipulation,and single-fiber tweezers for multiple-particle/cell trapping and assembly.

关键词： optical trapping photothermal effect optical force cell trapping and assembly

Biophotonic probes for bio-detection and imaging

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light(Science & Applications) 2021年第7期10卷 1185-1206页

作者： Ting Pan Dengyun Lu Hongbao Xin baojun li Institute of Nanophotonics Jinan UniversityGuangzhou 511443China

The rapid development of biophotonics and biomedical sciences makes a high demand on photonic structures to be interfaced with biological systems that are capable of manipulating light at small scales for sensitive detection of biological signals and precise imaging of cellular structures.However,conventional photonic structures based on artificial materials(either inorganic or toxic organic)inevitably show incompatibility and invasiveness when interfacing with biological systems.The design of biophotonic probes from the abundant natural materials,particularly biological entities such as virus,cells and tissues,with the capability of multifunctional light manipulation at target sites greatly increases the biocompatibility and minimizes the invasiveness to biological microenvironment.In this review,advances in biophotonic probes for bio-detection and imaging are reviewed.We emphatically and systematically describe biological entities-based photonic probes that offer appropriate optical properties,biocompatibility,and biodegradability with different optical functions from light generation,to light transportation and light modulation.Three representative biophotonic probes,i.e.,biological lasers,cell-based biophotonic waveguides and biomicrolenses,are reviewed with applications for bio-detection and imaging.Finally,perspectives on future opportunities and potential improvements of biophotonic probes are also provided.

关键词： probes precise artificial

For more and purer hydrogen-the progress and challenges in water gas shift reaction

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能源化学:英文版 2023年第8期83卷 363-396,I0010页

作者： limin Zhou Yanyan liu Shuling liu Huanhuan Zhang Xianli Wu Ruofan Shen Tao liu Jie Gao Kang Sun baojun li Jianchun Jiang 218 Laboratory for Energy Catalysis Research Center of Green CatalysisCollege of ChemistryZhengzhou UniversityZhengzhou 450001HenanChina Institute of Chemical Industry of Forest Products CAFNational Engineering Lab.for Biomass Chemical UtilizationNanjing 210042JiangsuChina College of Science Henan Agricultural UniversityZhengzhou 450002HenanChina National Center for Nanoscience and Technology Beijing 100190China School of life Sciences Northwestern Polytech UniversityXi'an 710072ShaanxiChina

The water gas shift(WGS) reaction is a standard reaction that is widely used in industrial hydrogen production and removal of carbon monoxide. The improved catalytic performance of WGS reaction also contributes to ammonia synthesis and other reactions. Advanced catalysts have been developed for both high and low-temperature reactions and are widely used in industry. In recent years, supported metal nanoparticle catalysts have been researched due to their high metal utilization. Low-temperature catalysts have shown promising results, including high selectivity, high shift rates, and higher activity potential. Additionally, significant progress has been made in removing trace CO through the redox reaction in electrolytic cell. This paper reviews the development of WGS reaction catalysts, including the reaction mechanism, catalyst design, and innovative research methods. The catalyst plays a crucial role in the WGS reaction, and this paper provides an instant of catalyst design under different conditions. The progress of catalysts is closely related to the development of advanced characterization techniques.Furthermore, modifying the catalyst surface to enhance activity and significantly increase reaction kinetics is a current research direction. This review goals to stimulate a better understanding of catalyst design, performance optimization, and driving mechanisms, leading to further progress in this field.

关键词： Water gas shift reaction Hydrogen production Heterogeneous catalysis Reaction Mechanism Single atomic catalysts

Successive Free-Radical C(sp^(2))-C(sp^(2)) Coupling Reactions to Form Graphene

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CCS Chemistry 2022年第2期4卷 584-597页

作者： Huaqiang Cao Cheng Wang baojun li Tianyu Chen Peng Han Yan Zhang Haijun Yang Qunyang li Anthony K.Cheetham Department of Chemistry Tsinghua UniversityBeijing 100084 Beijing Advanced Innovation Center for Imaging Technology and Key Laboratory of Terahertz Optoelectronics(MoE) Department of PhysicsCapital Normal UniversityBeijing 100048 Applied Mechanics Laboratory Department of Engineering MechanicsSchool of Aerospace EngineeringTsinghua UniversityBeijing 100084 Department of Materials Science and Metallurgy University of CambridgeCambridge CB30FS Materials Research Laboratory University of CaliforniaSanta BarbaraSanta BarbaraCA 93106

Graphene is of great interest because of its exciting properties and potential applications,but its production on a large-scale still presents considerable challenges.Herein,we report the synthesis of predominately few-layer graphene,due toπ–πstacking,and single-layer graphene from reaction between hexabromobenzene and Na metal,followed by annealing to improve crystallinity.The reaction proceeds via a free-radical C(sp^(2))–C(sp^(2))coupling mechanism,which is supported by theoretical calculations.The graphene can host unpaired spin electrons,leading to a short acquisition time for a solidstate nuclear magnetic resonance 13C spectrum from unlabeled graphene,which is ascribed to the very short spin-lattice relaxation time.High catalytic activity for transforming amine to imine with a conversion of>99%and a yield of∼97%is demonstrated,and high electronic conductivity of∼105 S·m^(−1) is found by terahertz spectroscopy.The reaction delivers a method for synthesizing graphene with a high spin concentration from perbrominated benzene molecules by using an active metallic agent,such as Na,li,or Mg.

关键词： graphene synthesis radical C(sp^(2))-C(sp^(2))coupling high electron spin density short spin-lattice relaxation metal-free amine conversion catalyst