Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hyd...Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hydrogen evolution reaction is enhanced under acidic conditions.Here,we report that the CO_(2) can be efficiently reduced into CH_(4) over a Cu catalyst by modifying with a glutamic acid molecule under acidic conditions.The CH_(4) Faradaic efficiency can reach 62.9% with a current density of 450 mA cm^(-2).Meanwhile,a single-pass carbon efficiency of 48.1% toward CH_(4) is achieved.Experiments revealed that the glutamic acid molecule can enhance the concentration of Kt on the surface of Cu,which can suppress the HER and promote CO_(2) reduction,resulting in high selectivity of CH_(4) under acidic conditions.展开更多
The CuO/CeO_(2) composites with strong metal-support interaction were synthesised,which can efficiently electroreduct CO_(2)to C(2)H_(4).The Faradaic efficiency(FE)of C_(2)H_(4) could reach 50.5%with a current density...The CuO/CeO_(2) composites with strong metal-support interaction were synthesised,which can efficiently electroreduct CO_(2)to C(2)H_(4).The Faradaic efficiency(FE)of C_(2)H_(4) could reach 50.5%with a current density of 18 mA cm^(-2).The strong metal-support interaction could not only enhance the adsorption and activation of CO_(2),but also can stablize the CuO.展开更多
Introducing vacancy defects and unique morphology is an effective strategy to improve the catalytic performance of transition metal compounds.However,precisely controlling the amount of vacancy defects remains challen...Introducing vacancy defects and unique morphology is an effective strategy to improve the catalytic performance of transition metal compounds.However,precisely controlling the amount of vacancy defects remains challenging.Here,we propose a facile and efficient hydrothermal accompanying an annealing method to synthesize a series of Mn-doped CoO nanomaterials with controllable oxygen vacancies and unique morphology.The oxygen vacancies amount can be precisely controlled by adjusting the Mndoping content and is positively correlated with catalytic performance.It was found that the oxygen vacancies amount can reach up to 38.2%over the Mn-doped CoO nanomaterials,resulting in ultra-high hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalytic activity(HER:25.6 and 37 m V at 10 m A cm^(-2);OER:301 and 322 m V at 50 m A cm^(-2))under both basic and acidic conditions,while reaching 10 m A cm^(-2) for an ultra-low cell voltage of only 1.52 V,which exceeds that of Pt/C/RuO_(2) and all reported non-noble metal oxide catalysts.The DFT calculations reveal oxygen vacancies can optimize H*and HOO*intermediates adsorption free energy,thus improving the HER and OER performance.Interestingly,the Mn-doped CoO with rich oxygen vacancies exhibits excellent antibacterial properties in vitro of biomedicine.This work provides new ideas and methods for the rational design and precise control of vacancy defects in transition metal compounds and explores their potential application value in electrochemical water splitting and biomedical fields.展开更多
Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach t...Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.展开更多
RHex-style robots can perform manifold moving gaits in different applications,but they have always faced a challenge of climbing up high obstacles.In this paper,the bionics-based gait optimization in an RHex-style rob...RHex-style robots can perform manifold moving gaits in different applications,but they have always faced a challenge of climbing up high obstacles.In this paper,the bionics-based gait optimization in an RHex-style robot is proposed for climbing steps at different heights,which even enables the robot to climb up the step with 4.2 times of the leg length.First,a thoracic flexion is designed in the robot,and an algorithm of adjusting body inclination is proposed to perform the rising stage after placing front legs on top of step,which can be applied in different RHex-style robots with different sizes.Especially,when the thoracic flexion is implemented,the robot can climb the higher step with the proposed algorithm.Second,to climbing the higher steps,a claw-shape legs-based algorithm is proposed for robot reaching the higher step and climbing it up.During the vital rising stage,when the front legs of the robot have reached the top of the step,the robot can bend the front body downward with its thoracic flexion like a cockroach,and then lift the front and middle legs alternately to move COM up and forward onto the step.The simulation analysis is utilized to verify the feasibility of the proposed algorithms.Finally,the step-climbing experiments at different heights are performed in our robot to compare with the existing works.The results of simulations and experiments show the superiority of the proposed algorithms for the improved robot due to climbing up the higher steps.展开更多
MoS_(2)is a promising electrocatalyst because of its natural abundance and outstanding electrochemical stability.However,the poor conductivity and low activity limit its catalytic performance;furthermore,MoS_(2)is una...MoS_(2)is a promising electrocatalyst because of its natural abundance and outstanding electrochemical stability.However,the poor conductivity and low activity limit its catalytic performance;furthermore,MoS_(2)is unable to satisfy the requirements of most industrial applications.In this study,to obtain a P-doped MoS_(2)catalyst with S vacancy defects,P is inserted into the MoS_(2)matrix via a solid phase ion exchange at room temperature.The optimal P-doping amount is 11.4 wt%,and the resultant catalyst delivers excellent electrocatalytic properties for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)with the corresponding overpotentials of 93 and 316 mV at 10 mA cm^(-2) in an alkaline solution;these values surpass the overpotentials of most previously reported MoS_(2)-based materials.Theoretical calculations and results demonstrate that the synergistic effect of the doped P,which forms active centers in the basal plane of MoS_(2),and S vacancy defects caused by P doping intensifies the intrinsic electronic conductivity and electrocatalytic activity of the catalyst.Density functional theory calculations demonstrate that P optimizes the free energy of the MoS_(2)matrix for hydrogen adsorption,thereby considerably increasing the intrinsic activity of the doped catalyst for the HER compared with that observed from pristine MoS_(2).The enhanced catalytic activity of P-doped MoS_(2)for the OER is attributed to the ability of the doped P which facilitates the adsorption of hydroxyl and hydroperoxy intermediates and reduces the reaction energy barrier.This study provides a new environmentally friendly and convenient solid-phase ion exchange method to improve the electrocatalytic capability of two-dimensional transition-metal dichalcogenides in largescale applications.展开更多
Electroreduction of carbon dioxide(CO_(2))into valuable chemicals and fuels is a promising strategy to mitigate energy and environmental problems.However,the poor selectivity and inadequate electrochemical stability p...Electroreduction of carbon dioxide(CO_(2))into valuable chemicals and fuels is a promising strategy to mitigate energy and environmental problems.However,the poor selectivity and inadequate electrochemical stability prevent practical applications.In this work,we prepared ultrasmall copper(Cu)nanoparticles by using tannic acid as a complexing agent and stablizer.The ultrasmall Cu nanoparticles(3.4 nm)exhibited outstanding performance for CO_(2)electroreduction to CH_(4).The Faradaic efficiency of CH_(4)could reach up to 68%at-1.2 V versus reversible hydrogen electrode(RHE),with high current density of 475 mA·cm^(-2).The ultrasmall Cu nanoparticles could enhance the CO adsorption and H2O activation,resulting in the high selectivity of CH_(4).展开更多
基金supported by the National Key Research and Development Program of China(2020YFA0710201)the China Postdoctoral Science Foundation Funded Project(2021M701211)+1 种基金Fundamental Research Funds for the Central Universities,“Island Atmosphere and Ecology”Category Ⅳ Peak Discipline(No.QN202505)the National Natural Science Foundation of China(22293015,22121002).
文摘Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hydrogen evolution reaction is enhanced under acidic conditions.Here,we report that the CO_(2) can be efficiently reduced into CH_(4) over a Cu catalyst by modifying with a glutamic acid molecule under acidic conditions.The CH_(4) Faradaic efficiency can reach 62.9% with a current density of 450 mA cm^(-2).Meanwhile,a single-pass carbon efficiency of 48.1% toward CH_(4) is achieved.Experiments revealed that the glutamic acid molecule can enhance the concentration of Kt on the surface of Cu,which can suppress the HER and promote CO_(2) reduction,resulting in high selectivity of CH_(4) under acidic conditions.
基金supported by the National Key Research and Development Program of China(2017YFA0403102)National Natural Science Foundation of China(21573073,21733011)+1 种基金Beijing Municipal Science&Technology Commission(Z191100007219009)the Chinese Academy of Sciences(QYZDY-SSW-SLH013)。
文摘The CuO/CeO_(2) composites with strong metal-support interaction were synthesised,which can efficiently electroreduct CO_(2)to C(2)H_(4).The Faradaic efficiency(FE)of C_(2)H_(4) could reach 50.5%with a current density of 18 mA cm^(-2).The strong metal-support interaction could not only enhance the adsorption and activation of CO_(2),but also can stablize the CuO.
基金supported by the National Natural Science Foundation of China(52072196,52002199,52002200,52102106)the Major Basic Research Program of the Natural Science Foundation of Shandong Province(ZR2020ZD09)+1 种基金the Innovation and Technology Program of Shandong Province(2020KJA004)the Taishan Scholars Program of Shandong Province(ts201511034)。
文摘Introducing vacancy defects and unique morphology is an effective strategy to improve the catalytic performance of transition metal compounds.However,precisely controlling the amount of vacancy defects remains challenging.Here,we propose a facile and efficient hydrothermal accompanying an annealing method to synthesize a series of Mn-doped CoO nanomaterials with controllable oxygen vacancies and unique morphology.The oxygen vacancies amount can be precisely controlled by adjusting the Mndoping content and is positively correlated with catalytic performance.It was found that the oxygen vacancies amount can reach up to 38.2%over the Mn-doped CoO nanomaterials,resulting in ultra-high hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalytic activity(HER:25.6 and 37 m V at 10 m A cm^(-2);OER:301 and 322 m V at 50 m A cm^(-2))under both basic and acidic conditions,while reaching 10 m A cm^(-2) for an ultra-low cell voltage of only 1.52 V,which exceeds that of Pt/C/RuO_(2) and all reported non-noble metal oxide catalysts.The DFT calculations reveal oxygen vacancies can optimize H*and HOO*intermediates adsorption free energy,thus improving the HER and OER performance.Interestingly,the Mn-doped CoO with rich oxygen vacancies exhibits excellent antibacterial properties in vitro of biomedicine.This work provides new ideas and methods for the rational design and precise control of vacancy defects in transition metal compounds and explores their potential application value in electrochemical water splitting and biomedical fields.
基金This work was supported in part by the National Natural Science Foundation of China(No.51605393)China Postdoctoral Science Foundation(No.2018M633398)+1 种基金State Key Laboratory of Robotics and Systems(HIT)(SKLRS-2020-KF-13)Sichuan Science and Technology Program(2020YJ0035).
文摘Inspired by the cockroach’s use of a pitch-roll mode traverses through narrow obstacles,we improve the RHex-style robot by adding two sprawl joints to adjust the body posture,and propose a novel pitch-roll approach that enables an RHex-style robot to traverse through two cylindrical obstacles with a spacing of 90 mm,about 54%body width.First,the robot can pitch up against the obstacle on the one side by the cooperation of its rear and middle legs.Then,the robot rotates one side rear leg to kick the ground fast,meanwhile the sprawl joint on the other side rotates inward to make the robot roll and fall forward.Finally,the robot can rotate the legs on the ground to move the body forward until it crosses the obstacles.In this article,both cylinder and rectangular columns are considered as the narrow obstacles for traversing.The experiments are demonstrated by using the proposed approach,and the results show that the robot can smoothly traverse through different narrow spaces.
基金This work was supported in part by the National Natural Science Foundation of China(No.51605393)State Key Laboratory of Robotics and Systems(HIT)(SKLRS-2020-KF-13)Sichuan Science and Technology Program(2020YJ0035).
文摘RHex-style robots can perform manifold moving gaits in different applications,but they have always faced a challenge of climbing up high obstacles.In this paper,the bionics-based gait optimization in an RHex-style robot is proposed for climbing steps at different heights,which even enables the robot to climb up the step with 4.2 times of the leg length.First,a thoracic flexion is designed in the robot,and an algorithm of adjusting body inclination is proposed to perform the rising stage after placing front legs on top of step,which can be applied in different RHex-style robots with different sizes.Especially,when the thoracic flexion is implemented,the robot can climb the higher step with the proposed algorithm.Second,to climbing the higher steps,a claw-shape legs-based algorithm is proposed for robot reaching the higher step and climbing it up.During the vital rising stage,when the front legs of the robot have reached the top of the step,the robot can bend the front body downward with its thoracic flexion like a cockroach,and then lift the front and middle legs alternately to move COM up and forward onto the step.The simulation analysis is utilized to verify the feasibility of the proposed algorithms.Finally,the step-climbing experiments at different heights are performed in our robot to compare with the existing works.The results of simulations and experiments show the superiority of the proposed algorithms for the improved robot due to climbing up the higher steps.
基金supported by the National Natural Science Foundation of China(52072196)the Major Basic Research Program of the Natural Science Foundation of Shandong Province(ZR2020ZD09)。
文摘MoS_(2)is a promising electrocatalyst because of its natural abundance and outstanding electrochemical stability.However,the poor conductivity and low activity limit its catalytic performance;furthermore,MoS_(2)is unable to satisfy the requirements of most industrial applications.In this study,to obtain a P-doped MoS_(2)catalyst with S vacancy defects,P is inserted into the MoS_(2)matrix via a solid phase ion exchange at room temperature.The optimal P-doping amount is 11.4 wt%,and the resultant catalyst delivers excellent electrocatalytic properties for the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)with the corresponding overpotentials of 93 and 316 mV at 10 mA cm^(-2) in an alkaline solution;these values surpass the overpotentials of most previously reported MoS_(2)-based materials.Theoretical calculations and results demonstrate that the synergistic effect of the doped P,which forms active centers in the basal plane of MoS_(2),and S vacancy defects caused by P doping intensifies the intrinsic electronic conductivity and electrocatalytic activity of the catalyst.Density functional theory calculations demonstrate that P optimizes the free energy of the MoS_(2)matrix for hydrogen adsorption,thereby considerably increasing the intrinsic activity of the doped catalyst for the HER compared with that observed from pristine MoS_(2).The enhanced catalytic activity of P-doped MoS_(2)for the OER is attributed to the ability of the doped P which facilitates the adsorption of hydroxyl and hydroperoxy intermediates and reduces the reaction energy barrier.This study provides a new environmentally friendly and convenient solid-phase ion exchange method to improve the electrocatalytic capability of two-dimensional transition-metal dichalcogenides in largescale applications.
基金the National Key Research and Development Program of China(grant no.2023YFA1507901)National Natural Science Foundation of China(grant nos.22003070,22293015,and 22121002).
文摘Electroreduction of carbon dioxide(CO_(2))into valuable chemicals and fuels is a promising strategy to mitigate energy and environmental problems.However,the poor selectivity and inadequate electrochemical stability prevent practical applications.In this work,we prepared ultrasmall copper(Cu)nanoparticles by using tannic acid as a complexing agent and stablizer.The ultrasmall Cu nanoparticles(3.4 nm)exhibited outstanding performance for CO_(2)electroreduction to CH_(4).The Faradaic efficiency of CH_(4)could reach up to 68%at-1.2 V versus reversible hydrogen electrode(RHE),with high current density of 475 mA·cm^(-2).The ultrasmall Cu nanoparticles could enhance the CO adsorption and H2O activation,resulting in the high selectivity of CH_(4).
