One of the most unique properties of two-dimensional carbides and nitrides of transition metals(MXenes)is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-s...One of the most unique properties of two-dimensional carbides and nitrides of transition metals(MXenes)is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-scale application is limited by their costly chemical synthesis methods.In this work,the niche feature of MXenes was capitalized in the packed-bed electrochemical reactor to produce MXenes at an unprecedented reaction rate and yield with minimal chemical waste.A simple NH4F solution was employed as the green electrolyte,which could be used repeatedly without any loss in its efficacy.Surprisingly,both fluoride and ammonium were found to play critical roles in the electrochemical etching,functionalization,and expansion of the layered parent materials(MAXs)through which the liberation of ammonia gas was observed.The electrochemically produced MXenes with excellent conductivity,applied as supercapacitor electrodes,could deliver an ultrahigh volumetric capacity(1408 F cm^(−3))and a volumetric energy density(75.8 Wh L^(−1)).This revolutionary green,energy-efficient,and scalable electrochemical route will not only pave the way for industrial-scale production of MXenes but also open up a myriad of versatile electrochemical modifications for improved functional MXenes.展开更多
The aim of this study was to investigate the potential protective effect of tetramethylpyrazine (TMP), one of available blood-activating and stasis-eliminating components from traditional Chinese medicines, on glutama...The aim of this study was to investigate the potential protective effect of tetramethylpyrazine (TMP), one of available blood-activating and stasis-eliminating components from traditional Chinese medicines, on glutamate-induced neurotoxicity in mice and its possible mechanism. Mice, except for controls, received simultaneously intragastric (ig) administration of monosodium glutamate [MSG, 4.0 g/(kg·d)] or/and intraperitoneal (ip) administration of TMP [10, 20, 40 mg/(kg·d)] for 10 d, and then behavioral tests, as well as histopathological and immunohistochemical examination of hippocampi were performed to analyze the glutamate-induced functional and morphological changes and the possible protective effect of TMP. The results showed that ip administration of TMP countered the effects of ig administration of MSG on behavior and histopathology, suggesting that TMP was a neuroprotective agent. This study provides evidence that TMP possesses obviously neuroprotection against glutamate-induced neurotoxicity, and the neuroprotection effect may result from its inhibiting expression of NMDARs, consequently blocking-up Ca2+ influx through the receptor’s associated ion channel, which can be neurotoxic.展开更多
This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts...This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts such as improved efficiency,selectivity,and flexibility due to their distinct electronic structure and unique properties.The review discusses the critical elements in the design of SACs,including the choice of metal atom,host material,and coordination environment,and how these elements impact the catalytic activity.The role of single atoms in photocatalytic H_(2)O_(2)production is also analysed,focusing on enhancing light absorption and charge generation,improving the migration and separation of charge carriers,and lowering the energy barrier of adsorption and activation of reactants.Despite these advantages,several challenges,including H_(2)O_(2)decomposition,stability of SACs,unclear mechanism,and low selectivity,need to be overcome.Looking towards the future,the review suggests promising research directions such as direct utilization of H_(2)O_(2),high-throughput synthesis and screening,the creation of dual active sites,and employing density functional theory for investigating the mechanisms of SACs in H_(2)O_(2)photosynthesis.This review provides valuable insights into the potential of single atom catalysts for advancing the field of photocatalytic H_(2)O_(2)production.展开更多
In the realm of photoenergy conversion,the scarcity of efficient light-driven semiconductors poses a significant obstacle to the advancement of photocatalysis,highlighting the critical need for researchers to explore ...In the realm of photoenergy conversion,the scarcity of efficient light-driven semiconductors poses a significant obstacle to the advancement of photocatalysis,highlighting the critical need for researchers to explore novel semiconductor materials.Herein,we present the inaugural synthesis of a novel semiconductor,CdNCN,under mild conditions,while shedding light on its formation mechanism.By effectively harnessing the[NCN]^(2⁻)moiety in the thiourea process,we successfully achieve the one-pot synthesis of CdNCN-CdS heterostructure photocatalysts.Notably,the optimal CdNCN-CdS sample demonstrates a hydrogen evolution rate of 14.7 mmol g^(-1)h^(-1)under visible light irradiation,establishing itself as the most efficient catalyst among all reported CdS-based composites without any cocatalysts.This outstanding hydrogen evolution performance of CdNCN-CdS primarily arises from two key factors:i)the establishment of an atomic-level N-Cd-S heterostructure at the interface between CdNCN and CdS,which facilitating highly efficient electron transfer;ii)the directed transfer of electrons to the(110)crystal plane of CdNCN,promoting optimal hydrogen adsorption and active participation in the hydrogen evolution reaction.This study provides a new method for synthesizing CdNCN materials and offers insights into the design and preparation of innovative atomic-level composite semiconductor photocatalysts.展开更多
基金Australian Research Council,Grant/Award Numbers:DP190100120,FT200100015National Key Research and Development Program,Grant/Award Number:2021YFA1600800Shenzhen Science and Technology Program,Grant/Award Numbers:RCJC20200714114434086,JCYJ20190808142001745,JCYJ20200812160737002,20180921273B。
文摘One of the most unique properties of two-dimensional carbides and nitrides of transition metals(MXenes)is their excellent water dispersibility and yet possessing superior electrical conductivity but their industrial-scale application is limited by their costly chemical synthesis methods.In this work,the niche feature of MXenes was capitalized in the packed-bed electrochemical reactor to produce MXenes at an unprecedented reaction rate and yield with minimal chemical waste.A simple NH4F solution was employed as the green electrolyte,which could be used repeatedly without any loss in its efficacy.Surprisingly,both fluoride and ammonium were found to play critical roles in the electrochemical etching,functionalization,and expansion of the layered parent materials(MAXs)through which the liberation of ammonia gas was observed.The electrochemically produced MXenes with excellent conductivity,applied as supercapacitor electrodes,could deliver an ultrahigh volumetric capacity(1408 F cm^(−3))and a volumetric energy density(75.8 Wh L^(−1)).This revolutionary green,energy-efficient,and scalable electrochemical route will not only pave the way for industrial-scale production of MXenes but also open up a myriad of versatile electrochemical modifications for improved functional MXenes.
文摘The aim of this study was to investigate the potential protective effect of tetramethylpyrazine (TMP), one of available blood-activating and stasis-eliminating components from traditional Chinese medicines, on glutamate-induced neurotoxicity in mice and its possible mechanism. Mice, except for controls, received simultaneously intragastric (ig) administration of monosodium glutamate [MSG, 4.0 g/(kg·d)] or/and intraperitoneal (ip) administration of TMP [10, 20, 40 mg/(kg·d)] for 10 d, and then behavioral tests, as well as histopathological and immunohistochemical examination of hippocampi were performed to analyze the glutamate-induced functional and morphological changes and the possible protective effect of TMP. The results showed that ip administration of TMP countered the effects of ig administration of MSG on behavior and histopathology, suggesting that TMP was a neuroprotective agent. This study provides evidence that TMP possesses obviously neuroprotection against glutamate-induced neurotoxicity, and the neuroprotection effect may result from its inhibiting expression of NMDARs, consequently blocking-up Ca2+ influx through the receptor’s associated ion channel, which can be neurotoxic.
基金This work was financially supported by the Guangdong Basic and Applied Basic Research Foundation(2020A1515010982)the National Natural Science Foundation of China(21805191)+2 种基金Shenzhen Science and Technology Program(JCYJ20210324094000001,20190808142001745,20200812122947002)Shenzhen Peacock Plan(20210802524B and 20180921273B)the Australian Research Council(FT200100015)。
文摘This comprehensive review provides a deep exploration of the unique roles of single atom catalysts(SACs)in photocatalytic hydrogen peroxide(H_(2)O_(2))production.SACs offer multiple benefits over traditional catalysts such as improved efficiency,selectivity,and flexibility due to their distinct electronic structure and unique properties.The review discusses the critical elements in the design of SACs,including the choice of metal atom,host material,and coordination environment,and how these elements impact the catalytic activity.The role of single atoms in photocatalytic H_(2)O_(2)production is also analysed,focusing on enhancing light absorption and charge generation,improving the migration and separation of charge carriers,and lowering the energy barrier of adsorption and activation of reactants.Despite these advantages,several challenges,including H_(2)O_(2)decomposition,stability of SACs,unclear mechanism,and low selectivity,need to be overcome.Looking towards the future,the review suggests promising research directions such as direct utilization of H_(2)O_(2),high-throughput synthesis and screening,the creation of dual active sites,and employing density functional theory for investigating the mechanisms of SACs in H_(2)O_(2)photosynthesis.This review provides valuable insights into the potential of single atom catalysts for advancing the field of photocatalytic H_(2)O_(2)production.
基金financially supported by the National Natural Science Foundation of China(Nos.22078118,22274059 and 42277219)the Natural Science Foundation of Guangdong Province,China(Nos.2023A1515010740 and 2023A1515030131).
文摘In the realm of photoenergy conversion,the scarcity of efficient light-driven semiconductors poses a significant obstacle to the advancement of photocatalysis,highlighting the critical need for researchers to explore novel semiconductor materials.Herein,we present the inaugural synthesis of a novel semiconductor,CdNCN,under mild conditions,while shedding light on its formation mechanism.By effectively harnessing the[NCN]^(2⁻)moiety in the thiourea process,we successfully achieve the one-pot synthesis of CdNCN-CdS heterostructure photocatalysts.Notably,the optimal CdNCN-CdS sample demonstrates a hydrogen evolution rate of 14.7 mmol g^(-1)h^(-1)under visible light irradiation,establishing itself as the most efficient catalyst among all reported CdS-based composites without any cocatalysts.This outstanding hydrogen evolution performance of CdNCN-CdS primarily arises from two key factors:i)the establishment of an atomic-level N-Cd-S heterostructure at the interface between CdNCN and CdS,which facilitating highly efficient electron transfer;ii)the directed transfer of electrons to the(110)crystal plane of CdNCN,promoting optimal hydrogen adsorption and active participation in the hydrogen evolution reaction.This study provides a new method for synthesizing CdNCN materials and offers insights into the design and preparation of innovative atomic-level composite semiconductor photocatalysts.
