Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate ...Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate and retarded desorption of target products.Engineering the interface microenvironment of catalysts has been proposed as a strategy to exert a significant influence on reaction outcomes,yet it remains a significant challenge.In this study,amino alkylation was successfully integrated into the melem unit of polymeric carbon nitrides(PCN),which could efficiently drive the photocatalytic CO_(2) reduction.Experimental characterization and theoretical calculations revealed that the introduction of amino alkylation lowers the energy barrier for CO_(2) reduction into^(*)COOH intermediate,transforming the adsorption of^(*)COOH intermediate from the endothermic to an exothermic process.Notably,the as-prepared materials demonstrated outstanding performance in photocatalytic CO_(2) reduction,yielding CO_(2)at a rate of 152.8μmol h^(-1) with a high selectivity of 95.4%and a quantum efficiency of 6.6%.展开更多
Sodium-ion batteries(SIBs)have been considered as an ideal choice for the next generation large-scale energy storage applications owing to the rich sodium resources and the analogous working principle to that of lithi...Sodium-ion batteries(SIBs)have been considered as an ideal choice for the next generation large-scale energy storage applications owing to the rich sodium resources and the analogous working principle to that of lithium-ion batteries(LIBs).Nevertheless,the larger size and heavier mass of Na^(+)ion than those of Li^(+)ion often lead to sluggish reaction kinetics and inferior cycling life in SIBs compared to the LIB counterparts.The pursuit of promising electrode materials that can accommodate the rapid and stable Na-ion insertion/extraction is the key to promoting the development of SIBs toward a commercial prosperity.One-dimensional(1 D)nanomaterials demonstrate great prospects in boosting the rate and cycling performances because of their large active surface areas,high endurance for deformation stress,short ions diffusion channels,and oriented electrons transfer paths.Electrospinning,as a versatile synthetic technology,features the advantages of controllable preparation,easy operation,and mass production,has been widely applied to fabricate the 1 D nanostructured electrode materials for SIBs.In this review,we comprehensively summarize the recent advances in the sodium-storage cathode and anode materials prepared by electrospinning,discuss the effects of modulating the spinning parameters on the materials’micro/nano-structures,and elucidate the structure-performance correlations of the tailored electrodes.Finally,the future directions to harvest more breakthroughs in electrospun Na-storage materials are pointed out.展开更多
LiNiCoAlO（NCA） with Zr（OH）coating is demonstrated as high performance cathode material for lithium ion batteries（LIBs）. The coated materials are synthesized via a simple dry coating method of NCA with Zr（OH）po...LiNiCoAlO（NCA） with Zr（OH）coating is demonstrated as high performance cathode material for lithium ion batteries（LIBs）. The coated materials are synthesized via a simple dry coating method of NCA with Zr（OH）powders, and then characterized with scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and X-ray photoelectron spectroscopy（XPS）. Experimental results show that amorphous Zr（OH）powders have been successfully coated on the surface of spherical NCA particles, exhibiting improved electrochemical performance. 0.50 wt% Zr（OH）coated NCA delivers a capacity of 197.6 mAh/g at the first cycle and 154.3 mAh/g after 100 cycles with a capacity retention of 78.1% at 1 C rate. In comparison, the pure NCA shows a capacity of 194.6 mAh/g at the first cycle and 142.5 mAh/g after 100 cycles with a capacity retention of 73.2% at 1 C rate. Electrochemical impedance spectroscopy（EIS） results show that the coated material exhibits a lower resistance, indicating that the coating layer can efficiently suppress transition metals dissolution and decrease the side reactions at the surface between the electrode and electrolyte. Therefore, surface coating with amorphous Zr（OH）is a simple and useful method to enhance the electrochemical performance of NCA-based materials for the cathode of LIBs.展开更多
Molecular doping has been proven to be an effective approach to adjusting the electronic structure of polymeric carbon nitride(PCN)and thus improving its optical properties and photocatalytic activity.Herein,theobromi...Molecular doping has been proven to be an effective approach to adjusting the electronic structure of polymeric carbon nitride(PCN)and thus improving its optical properties and photocatalytic activity.Herein,theobromine,a compound composed of an imidazole ring and a pyrimidine ring,was first copolymerized with urea to prepared doped PCN.Experimental investigations and theoretical calculations indicate that,a narrowing in band gap and a positive shift in valence band positon happened to the theobromine doped PCN,owing to the synergistic effect between the pyrimidine ring and the imidazole ring in the theobromine molecule.Moreover,it is shown that the doping with theobromine at a suitable mass fraction makes the obtained sample exhibit decreased photoluminescent emission,enhanced photocurrent density,and reduced charge-transport resistance.Consequently,an enhancement in the photocatalytic activity for water oxidation is found for the sample,which oxygen evolution rate is 4.43 times higher than that of the undoped PCN.This work sheds light on the choice of the molecular dopants for PCN to improve its photocatalytic performance.展开更多
The conventional ceramic synthesis of perovskite oxides involves extended high-temperature annealing in air and is unfavorable to the in situ hybridization of the conductive agent, thus resulting in large particle siz...The conventional ceramic synthesis of perovskite oxides involves extended high-temperature annealing in air and is unfavorable to the in situ hybridization of the conductive agent, thus resulting in large particle sizes, low surface area and limited electrochemical activities. Here we report a rapid gel auto-combustion approach for the synthesis of a perovskite/carbon hybrid at a low temperature of 180℃. The energy-saving synthetic strategy allows the formation of small and homogeneously dispersed LaxMnO3±6/C nanocomposites. Remarkably, the synthesized La0.99MnO3.03/C nanocomposite exhibits comparable oxygen reduction reaction （ORR） activity （with onset and peak potentials of 0.97 and 0.88 V, respectively） to the benchmark Pt/C due to the facilitated charge transfer, optimal eg electron filling of Mn, and coupled C-O-Mn bonding. Furthermore, the nanocomposite efficiently catalyzes a Zn-air battery that delivers a peak power density of 430 mW·cm^-2, an energy density of 837 W·h·kgzn^-1 and 340 h stability at a current rate of 10 mA·cm^-2.展开更多
Nanostructured organic tetralithium salts of 2,5-dihydroxyterephthalic acid （Li4C8H2O6） supported on graphene were prepared via a facile recrystallization method. The optimized composite with 75 wt.% Li4C8H2O6 was e...Nanostructured organic tetralithium salts of 2,5-dihydroxyterephthalic acid （Li4C8H2O6） supported on graphene were prepared via a facile recrystallization method. The optimized composite with 75 wt.% Li4C8H2O6 was evaluated as an anode with redox couples of Li4C8H2O6/Li6C8H2O6 and as a cathode with redox couples of Li4C8H2O6/Li2C8H2O6 for Li-ion batteries, exhibiting a high-rate capability （10 C） and long cycling life （1,000 cycles）. Moreover, in an all-organic symmetric Li-ion battery, this dual-function electrode retained capacities of 191 and 121 mA.h·g-1 after 100 and 500 cycles, respectively. Density functional theory calculations indicated the presence of covalent bonds between Li4CsH206 and graphene, which affected both the morphology and electronic structure of the composite. The special nanostructures, high electronic conductivity of graphene, and covalent-bond interaction between Li4C8H2O6 and graphene contributed to the superior electrochemical properties. Our results indicate that the combination of organic salt molecules with graphene is useful for obtaining high-performance organic batteries.展开更多
In the field of agriculture,variable-rate herbicide spraying(VRHS)technology has been used to solve the low efficiency of pesticides and crop chemical residues.The key of VRHS is the quick and precise identification o...In the field of agriculture,variable-rate herbicide spraying(VRHS)technology has been used to solve the low efficiency of pesticides and crop chemical residues.The key of VRHS is the quick and precise identification of weeds from field images,which forms a weed map.Fluid search optimization(FSO)was able to simplify the threshold optimization process to create a weed map,which simulated the fluid flowing from high pressure to low pressure,but it is time consuming and often converges prematurely.So,an explosion mechanism and a twophase optimization were introduced to improve the FSO-based segmentation algorithm.Experiments of segmentation weeds from a corn field at seedling growth stage showed that the IFSO algorithm obtained the best accuracy of 93.3%and the least running time of 0.019 s,compared with the standard PSO,GA,and FSO algorithms.展开更多
基金financially supported by the National Natural Science Foundation of China(22309032)the Guangdong Basic and Applied Basic Research Foundation(2022A1515011737)+1 种基金the Science and Technology Program of Guangzhou(2023A04J1395)the GDAS’Project of Science and Technology Development(2021GDASYL-20210102010)。
文摘Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate and retarded desorption of target products.Engineering the interface microenvironment of catalysts has been proposed as a strategy to exert a significant influence on reaction outcomes,yet it remains a significant challenge.In this study,amino alkylation was successfully integrated into the melem unit of polymeric carbon nitrides(PCN),which could efficiently drive the photocatalytic CO_(2) reduction.Experimental characterization and theoretical calculations revealed that the introduction of amino alkylation lowers the energy barrier for CO_(2) reduction into^(*)COOH intermediate,transforming the adsorption of^(*)COOH intermediate from the endothermic to an exothermic process.Notably,the as-prepared materials demonstrated outstanding performance in photocatalytic CO_(2) reduction,yielding CO_(2)at a rate of 152.8μmol h^(-1) with a high selectivity of 95.4%and a quantum efficiency of 6.6%.
基金Financial support from the National Natural Science Foundation of China(21805007)Young Elite Scientists Sponsorship Program by CAST(2018QNRC001)+3 种基金Beijing Natural Science Foundation(L182019)National Key Research and Development Program of China(2018YFB0104300)Fundamental Research Funds for the Central Universities(FRF-TP-19-029A2)111 Project(B12015)。
文摘Sodium-ion batteries(SIBs)have been considered as an ideal choice for the next generation large-scale energy storage applications owing to the rich sodium resources and the analogous working principle to that of lithium-ion batteries(LIBs).Nevertheless,the larger size and heavier mass of Na^(+)ion than those of Li^(+)ion often lead to sluggish reaction kinetics and inferior cycling life in SIBs compared to the LIB counterparts.The pursuit of promising electrode materials that can accommodate the rapid and stable Na-ion insertion/extraction is the key to promoting the development of SIBs toward a commercial prosperity.One-dimensional(1 D)nanomaterials demonstrate great prospects in boosting the rate and cycling performances because of their large active surface areas,high endurance for deformation stress,short ions diffusion channels,and oriented electrons transfer paths.Electrospinning,as a versatile synthetic technology,features the advantages of controllable preparation,easy operation,and mass production,has been widely applied to fabricate the 1 D nanostructured electrode materials for SIBs.In this review,we comprehensively summarize the recent advances in the sodium-storage cathode and anode materials prepared by electrospinning,discuss the effects of modulating the spinning parameters on the materials’micro/nano-structures,and elucidate the structure-performance correlations of the tailored electrodes.Finally,the future directions to harvest more breakthroughs in electrospun Na-storage materials are pointed out.
基金supported by the National Projects of NSFC(21322101 and 21231005)MOE(B12015 and IRT13R30)
文摘LiNiCoAlO（NCA） with Zr（OH）coating is demonstrated as high performance cathode material for lithium ion batteries（LIBs）. The coated materials are synthesized via a simple dry coating method of NCA with Zr（OH）powders, and then characterized with scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and X-ray photoelectron spectroscopy（XPS）. Experimental results show that amorphous Zr（OH）powders have been successfully coated on the surface of spherical NCA particles, exhibiting improved electrochemical performance. 0.50 wt% Zr（OH）coated NCA delivers a capacity of 197.6 mAh/g at the first cycle and 154.3 mAh/g after 100 cycles with a capacity retention of 78.1% at 1 C rate. In comparison, the pure NCA shows a capacity of 194.6 mAh/g at the first cycle and 142.5 mAh/g after 100 cycles with a capacity retention of 73.2% at 1 C rate. Electrochemical impedance spectroscopy（EIS） results show that the coated material exhibits a lower resistance, indicating that the coating layer can efficiently suppress transition metals dissolution and decrease the side reactions at the surface between the electrode and electrolyte. Therefore, surface coating with amorphous Zr（OH）is a simple and useful method to enhance the electrochemical performance of NCA-based materials for the cathode of LIBs.
基金supported by the National Natural Science Foundation of China(21276088,U1507201)Natural Science Foundation of Guangdong Province(2014A030312009)China Postdoctoral Science Foundation(2018M640784)~~
文摘Molecular doping has been proven to be an effective approach to adjusting the electronic structure of polymeric carbon nitride(PCN)and thus improving its optical properties and photocatalytic activity.Herein,theobromine,a compound composed of an imidazole ring and a pyrimidine ring,was first copolymerized with urea to prepared doped PCN.Experimental investigations and theoretical calculations indicate that,a narrowing in band gap and a positive shift in valence band positon happened to the theobromine doped PCN,owing to the synergistic effect between the pyrimidine ring and the imidazole ring in the theobromine molecule.Moreover,it is shown that the doping with theobromine at a suitable mass fraction makes the obtained sample exhibit decreased photoluminescent emission,enhanced photocurrent density,and reduced charge-transport resistance.Consequently,an enhancement in the photocatalytic activity for water oxidation is found for the sample,which oxygen evolution rate is 4.43 times higher than that of the undoped PCN.This work sheds light on the choice of the molecular dopants for PCN to improve its photocatalytic performance.
文摘The conventional ceramic synthesis of perovskite oxides involves extended high-temperature annealing in air and is unfavorable to the in situ hybridization of the conductive agent, thus resulting in large particle sizes, low surface area and limited electrochemical activities. Here we report a rapid gel auto-combustion approach for the synthesis of a perovskite/carbon hybrid at a low temperature of 180℃. The energy-saving synthetic strategy allows the formation of small and homogeneously dispersed LaxMnO3±6/C nanocomposites. Remarkably, the synthesized La0.99MnO3.03/C nanocomposite exhibits comparable oxygen reduction reaction （ORR） activity （with onset and peak potentials of 0.97 and 0.88 V, respectively） to the benchmark Pt/C due to the facilitated charge transfer, optimal eg electron filling of Mn, and coupled C-O-Mn bonding. Furthermore, the nanocomposite efficiently catalyzes a Zn-air battery that delivers a peak power density of 430 mW·cm^-2, an energy density of 837 W·h·kgzn^-1 and 340 h stability at a current rate of 10 mA·cm^-2.
文摘Nanostructured organic tetralithium salts of 2,5-dihydroxyterephthalic acid （Li4C8H2O6） supported on graphene were prepared via a facile recrystallization method. The optimized composite with 75 wt.% Li4C8H2O6 was evaluated as an anode with redox couples of Li4C8H2O6/Li6C8H2O6 and as a cathode with redox couples of Li4C8H2O6/Li2C8H2O6 for Li-ion batteries, exhibiting a high-rate capability （10 C） and long cycling life （1,000 cycles）. Moreover, in an all-organic symmetric Li-ion battery, this dual-function electrode retained capacities of 191 and 121 mA.h·g-1 after 100 and 500 cycles, respectively. Density functional theory calculations indicated the presence of covalent bonds between Li4CsH206 and graphene, which affected both the morphology and electronic structure of the composite. The special nanostructures, high electronic conductivity of graphene, and covalent-bond interaction between Li4C8H2O6 and graphene contributed to the superior electrochemical properties. Our results indicate that the combination of organic salt molecules with graphene is useful for obtaining high-performance organic batteries.
基金This work is supported by the Science&Technology Development Project of Jilin Province,China(20190302117GX,20180101334JC,20190301024NY)Innovation Capacity Construction Project of Jilin Province Development and Reform Commission(2019C053-3).
文摘In the field of agriculture,variable-rate herbicide spraying(VRHS)technology has been used to solve the low efficiency of pesticides and crop chemical residues.The key of VRHS is the quick and precise identification of weeds from field images,which forms a weed map.Fluid search optimization(FSO)was able to simplify the threshold optimization process to create a weed map,which simulated the fluid flowing from high pressure to low pressure,but it is time consuming and often converges prematurely.So,an explosion mechanism and a twophase optimization were introduced to improve the FSO-based segmentation algorithm.Experiments of segmentation weeds from a corn field at seedling growth stage showed that the IFSO algorithm obtained the best accuracy of 93.3%and the least running time of 0.019 s,compared with the standard PSO,GA,and FSO algorithms.
