碱性析氢反应(HER)可将间歇性可再生能源转化为可存储的清洁能源,因而备受关注.然而,水解离速度缓慢以及H中间体(*H)吸附和解吸困难限制了碱性HER的进一步发展.目前,针对碱性电解水解离缓慢问题,通常采用调整电催化剂结构降低水分解热...碱性析氢反应(HER)可将间歇性可再生能源转化为可存储的清洁能源,因而备受关注.然而,水解离速度缓慢以及H中间体(*H)吸附和解吸困难限制了碱性HER的进一步发展.目前,针对碱性电解水解离缓慢问题,通常采用调整电催化剂结构降低水分解热动力学能垒,以及改变三相界面微环境加速中间产物的扩散等方法来促进水分解进行.此外,可以通过调控活性位点电子结构来优化*H的吸脱附.但是采用单一的策略很难同时促进H_(2)O的解离和*H的吸脱附,难以获得令人满意的碱性HER性能.因此,探索一种能同时促进H_(2)O的解离和*H的吸脱附协同策略对提升碱性HER的性能至关重要.本文提出了一种协同策略,通过构建高曲率二硫化钴纳米针(CoS_(2)NNs)和原子级铜(Cu)的掺杂分别实现诱导纳米尺度的局域电场和原子尺度的电子局域化,从而促进碱性HER的H_(2)O解离和*H吸脱附.首先,采用有限元法模拟和密度泛函理论计算,从理论上分别证实了纳米尺度局域电场可以加速H_(2)O解离以及原子尺度电子局域化可以促进*H吸附.受理论计算结果启发,通过一步水热法和原位硫化相结合的方法制备了高曲率的Cu掺杂CoS_(2)纳米针(Cu-CoS_(2)NNs).采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和四探针测试等技术进行表征,研究了Cu-CoS_(2)NNs的形貌、物相结构、化学组成和导电性.结果表明,在Cu原子引入后,Cu-CoS_(2)NNs依然保持着高曲率的纳米针结构,证明了Cu在CoS_(2)NNs中的原子分散状态.相较于低曲率的Cu掺杂CoS_(2)纳米线(Cu-CoS_(2)NWs),Cu-CoS_(2)NNs只存在形貌上的区别,二者的化学组成和比例均非常接近.同时,上述材料都具有很强的导电性,且电导率基本相同,这与有限元模拟结果一致.原位衰减全反射红外光谱和电响应测试结果表明,Cu-CoS_(2)NNs具有较好的解离H_(2)O和吸附*H的能力.在1 mol L^(-1)KOH溶液和10 mA cm^(-2)电流密度下,该催化剂的析氢过电位仅为64 mV,展现出较好的电化学析氢性能.催化剂还表现出非常好的碱性析氢稳定性,在标准氢电势(RHE)-0.18 V下,可在100 mA cm^(-2)电流密度下稳定工作达100 h.综上所述,本文通过诱导局域电场和电子局域化构建了一种协同策略,所制备的Cu-CoS_(2)NNs表现出很好的催化碱性HER性能和应用前景,为碱性HER电催化剂的理性设计提供了一定的参考.展开更多
The use of gas diffusion electrode(GDE)based flow cell can realize industrial-scale CO_(2) reduction reactions(CO_(2)RRs).Controlling local CO_(2) and CO intermediate diffusion plays a key role in CO_(2)RR toward mult...The use of gas diffusion electrode(GDE)based flow cell can realize industrial-scale CO_(2) reduction reactions(CO_(2)RRs).Controlling local CO_(2) and CO intermediate diffusion plays a key role in CO_(2)RR toward multi-carbon(C_(2+))products.In this work,local CO_(2) and CO intermediate diffusion through the catalyst layer(CL)was investigated for improving CO_(2)RR toward C_(2+)products.The gas permeability tests and finite element simulation results indicated CL can balance the CO_(2) gas diffusion and residence time of the CO intermediate,leading to a sufficient CO concentration with a suitable CO_(2)/H_(2)O supply for high C_(2+)products.As a result,an excellent selectivity of C_(2+)products~79%at a high current density of 400 mA·cm^(-2) could be obtained on the optimal 500 nm Cu CL(Cu500).This work provides a new insight into the optimization of CO_(2)/H_(2)O supply and local CO concentration by controlling CL for C_(2+)products in CO_(2)RR flow cell.展开更多
电催化CO_(2)减排技术利用电能将过量的CO_(2)转化为有附加值的化学品,是解决能源危机、实现碳中和的有效途径之一.电催化CO_(2)还原反应(CO_(2)RR)中的多碳产物(C_(2)),如乙烯和乙醇,因其比C1产物具有更高的能量密度和更广泛的应用而...电催化CO_(2)减排技术利用电能将过量的CO_(2)转化为有附加值的化学品,是解决能源危机、实现碳中和的有效途径之一.电催化CO_(2)还原反应(CO_(2)RR)中的多碳产物(C_(2)),如乙烯和乙醇,因其比C1产物具有更高的能量密度和更广泛的应用而受到较大关注.目前为止,Cu基催化剂被认为是获得C_(2)产物的独特材料.研究者在提高Cu基催化剂C_(2)产物的活性和选择性方面做了大量的工作,如催化剂形貌工程、活性位点设计和中间吸附性能调控等.许多理论和实验研究已经证明,Cu基催化剂上的C-C偶联过程是C_(2)产物生成的速率决定步骤.优化C-C偶联过程的能垒是提高C_(2)产物活性和选择性的重要而直接的策略.CO_(2)RR在Cu上是由CO_(2)还原吸附CO(*CO)并二聚生成C_(2)产物引起的.C-C偶联过程与*CO的吸附性能密切相关.众所周知,CO是一种典型的极性分子,因此其在催化剂表面的吸附性能可能会受到活性位点周围的局部电场的影响.构建合适的局部电场是调节CO吸附性能和C-C偶联过程的潜在手段之一.前期工作(Nature,2016,537,382-386)证明了高曲率金纳米针可以在尖端产生高的局部电场.高局域电场诱导K+聚集,使活性位点周围CO_(2)浓度升高,大大促进了Au纳米针上的CO生成.基于Au纳米针的局域电场促进了CO_(2)RR的CO生成.本文利用Cu纳米针促进并优化C-C偶联反应来提高C_(2)产物活性和选择性.结果表明,局部电场可以促进C-C偶联过程,进而增强CO_(2)电还原生成C_(2)产物.有限元模拟结果表明,高曲率铜纳米针处存在较强的局部电场;密度泛函理论计算结果表明,强电场能促进C-C耦合过程.在此基础上,制备了一系列不同曲率的Cu催化剂,其中,Cu纳米针(CuNNs)的曲率最高,Cu纳米棒(CuNRs)和Cu纳米颗粒(CuNPs)曲率次之.实验测得CuNNs上吸附的K+浓度最高,证明了纳米针上的局部电场最强.同时,CO吸附传感器测试表明,CuNNs对CO的吸附能力最强,原位傅里叶变换红外光谱显示,CuNNs的*COCO和*CO信号最强.由此可见,高曲率铜纳米针可以诱导高局部电场,从而促进C-C耦合过程.催化性能测试结果表明,在低电位(-0.6 V vs.RHE)下,Cu NNs对CO_(2)RR的生成C_(2)产物的法拉第效率值为44%,约为Cu NPs的2.2倍.综上,本文为CO_(2)RR过程中提高多碳产物提供了新的思路.展开更多
Copper (Cu) is a special electrocatalyst for CO_(2) reduction reaction (CO_(2)RR) to multi-carbon products.Experimentally introducing grain boundaries (GBs) into Cu-based catalysts is an efficient strategy to improve ...Copper (Cu) is a special electrocatalyst for CO_(2) reduction reaction (CO_(2)RR) to multi-carbon products.Experimentally introducing grain boundaries (GBs) into Cu-based catalysts is an efficient strategy to improve the selectivity of C^(2+) products.However,it is still elusive for the C^(2+) product generation on Cu GBs due to the complex active sites.In this work,we found that the tandem catalysis pathway on adjacent active motifs of Cu GB is responsible for the enhanced activity for C^(2+)production by first principles calculations.By electronic structure analysis shows,the d-band center of GB site is close to the Fermi level than Cu(100) facet,the Cu atomic sites at grain boundary have shorter bond length and stronger bonding with*CO,which can enhance the adsorption of*CO at GB sites.Moreover,CO_(2)protonation is more favorable on the region Ⅲ motif (0.84 e V) than at Cu(100) site (1.35 e V).Meanwhile,the region Ⅱ motif also facilitate the C–C coupling (0.72 e V) compared to the Cu(100) motif (1.09 e V).Therefore,the region Ⅲ and Ⅱ motifs form a tandem catalysis pathway,which promotes the C^(2+)selectivity on Cu GBs.This work provides new insights into CO_(2)RR process.展开更多
Converting carbon dioxide(CO2)into value-added chemicals by CO2 reduction has been considered as a potential way to solve the current energy crisis and environmental problem.Among the methods of CO2 reduction,the elec...Converting carbon dioxide(CO2)into value-added chemicals by CO2 reduction has been considered as a potential way to solve the current energy crisis and environmental problem.Among the methods of CO2 reduction,the electrochemical method has been widely used due to its mild reaction condition and high reaction efficiency.In the electrochemical reduction system,the CO2 electrocatalyst is the most important part.Although many CO2 electrocatalysts have been developed,efficient catalysts with high activity,selectivity and stability are still lacking.Copper sulfide compound,as a low-toxicity and emerging material,has broad prospects in the field of CO2 reduction due to its unique structural and electrochemical properties.Much progress has been achieved with copper sulfide nanocrystalline and the field is rapidly developing.This paper summarizes the preparation,recent progress in development,and factors affecting the electrocatalytic CO2 reduction performance with copper sulfide compound as a catalyst.Prospects for future development are also outlined,with the aim of using copper sulfide compound as a highly active and stable electrocatalyst for CO2 reduction.展开更多
Now,Pt-based materials are still the best catalysts for hydrogen evolution reaction(HER).Nevertheless,the scarcity of Pt makes it impossible for the large-scale applications in industry.Although cobalt is taken as an ...Now,Pt-based materials are still the best catalysts for hydrogen evolution reaction(HER).Nevertheless,the scarcity of Pt makes it impossible for the large-scale applications in industry.Although cobalt is taken as an excellent HER catalyst due to its suitable H*binding,its alkali HER catalytic property need to be improved because of the sluggish water dissociation kinetics.In this work,nitrogen with small atomic radius and metallophilicity is employed to adjust local charges of atomically dispersed Mo^(δ+)sites on Co nanosheets to trigger water dissociation.Theoretical calculations suggest that the energy barrier of water dissociation can be effectively reduced by introducing nitrogen coordinated Mo^(δ+)sites.To realize this speculation,atomically dispersed Mo^(δ+)sites with nitrogen coordination of Mo(N)/Co were prepared via reconstruction of CoMoO_(4).High angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)and X-ray absorption spectroscopy(XAS)demonstrate the coordination of N atoms with atomically dispersed Mo atoms,leading to the local charges of atomically dispersed Mo^(δ+)sites in Mo(N)/Co.The measurement from ambient pressure X-ray photoelectron spectroscopy(AP-XPS)reveals that the Mo^(δ+)sites promote the adsorption and activation of water molecule.Therefore,the Mo(N)/Co exhibits an excellent activity,which need only an overpotential of 39 mV to reach the current density of 10 mA cm^(-2).The proposed strategy provides an advance pathway to design and boost alkaline HER activity at the atomic-level.展开更多
Formate is an important liquid chemical,which can be produced by electrocatalytic carbon dioxide reduction reaction(CO_(2) RR).Most of the metal catalysts for CO_(2) RR to formate are toxic or noble metals,such as Cd,...Formate is an important liquid chemical,which can be produced by electrocatalytic carbon dioxide reduction reaction(CO_(2) RR).Most of the metal catalysts for CO_(2) RR to formate are toxic or noble metals,such as Cd,Hg,Pb and Pd,leading to the environmental pollution or increased production costs.Herein,we develop an environmentally friendly and low-cost NiZn alloy catalyst for CO_(2) RR to formate.The X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM) confirm the alloy structure of the prepared NiZn catalyst. As for a catalyst for CO_(2) RR,the NiZn alloy exhibits the FE_(HCOO)^(-)(Faraday efficiency of HCOO^(-)) of 36±0.7% at-0.9 V vs.RHE in 0.1 M KHCO_(3), and remarkable stability for 40,000 s at-0.8,-0.9,-1.0 and-1.1 V vs.RHE,respectively.Theoretical calculation results indicate that the NiZn alloy exhibits the middle valence electron structure between the Zn and Ni metal,resulting in the favorable pathway for HCOOH formation but unfavorable for the hydrogen evolution reaction and CO production.The Ultraviolet Photoelectron Spectroscopy results verify the modulated valence electron structure for NiZn alloy as compared to Ni and Zn,consistent with the theoretical calculation results.This work provides new insights into design of alloy catalysts for CO_(2) RR to formate.展开更多
Histone methylation plays crucial roles in regulating chromatin structure and gene transcrip-tion in epigenetic modifications.Lysine-specific demethylase 1(LSD1),the first identified histone de-methylase,is universall...Histone methylation plays crucial roles in regulating chromatin structure and gene transcrip-tion in epigenetic modifications.Lysine-specific demethylase 1(LSD1),the first identified histone de-methylase,is universally overexpressed in various diseases.LSD1 dysregulation is closely associated with cancer,viral infections,and neurodegenerative diseases,etc.,making it a promising therapeutic target.Several LSD1 inhibitors and two small-molecule degraders(UM171 and BEA-17)have entered the clinical stage.LSD1 can remove methyl groups from histone 3 at lysine 4 or lysine 9(H3K4 or H3K9),resulting in either transcription repression or activation.While the roles of LSD1 in transcrip-tional regulation are well-established,studies have revealed that LSDl can also be dynamically regulated by other factors.For example,the expression or activity of LSD1 can be regulated by many proteins that form transcriptional corepressor complexes with LSD1.Moreover,some post-transcriptional modifica-tions and cellular metabolites can also regulate LSD1 expression or its demethylase activity.Therefore,in this review,we will systematically summarize how proteins involved in the transcriptional corepressor complex,various post-translational modifications,and metabolites act as regulatory factors for LSD1 ac-tivity.展开更多
To suppress the recombination of photogenerated electron and hole in single photocatalysts,an important method is to design heterojunction by combining two photocatalysts.This method has widely used to enhance the pho...To suppress the recombination of photogenerated electron and hole in single photocatalysts,an important method is to design heterojunction by combining two photocatalysts.This method has widely used to enhance the photocatalytic performance of the composites.At the begining,most people use type-Ⅱcharge carrier transfer mechanism to explain the emhanced activity of the composite semiconductors.展开更多
Photocatalytic reduction of CO_(2) into valuable fuels is one of the potential strategies to solve the carbon cycle and energy crisis.Graphitic carbon nitride(g-C_(3)N_(4)),as a typical two-dimensional(2D)semiconducto...Photocatalytic reduction of CO_(2) into valuable fuels is one of the potential strategies to solve the carbon cycle and energy crisis.Graphitic carbon nitride(g-C_(3)N_(4)),as a typical two-dimensional(2D)semiconductor with a bandgap of∼2.7 eV,has attracted wide attention in photocatalytic CO_(2) reduction.However,the performance of g-C_(3)N_(4) is greatly limited by the rapid recombination of photogenerated charge carriers and weak CO_(2) activation capacity.Construction of van der Waals heterostructure with the maximum interface contact area can improve the transfer/seperation efficiency of interface charge carriers.Ultrathin metal antimony(Sb)nanosheet(antimonene)with high carrier mobility and 2D layered structure,is a good candidate material to construct 2D/2D Sb/g-C_(3)N_(4) van der Waals heterostructure.In this work,the density functional theory(DFT)calculations indicated that antimonene has higher carrier mobility than g-C_(3)N_(4) nanosheets.Obvious charge transfer and in-plane structure distortion will occur at the interface of Sb/g-C_(3)N_(4),which endow stronger CO_(2) activation ability on di-coordinated N active site.The ultrathin g-C_(3)N_(4) and antimonene nanosheets were prepared by ultrasonic exfoliation method,and Sb/g-C_(3)N_(4) van der Waals heterostructures were constructed by self-assembly process.The photoluminescence(PL)and time-resolved photoluminescence(TRPL)indicated that the Sb/g-C_(3)N_(4) van der Waals heterostructures have a better photogenerated charge separation efficiency than pure g-C_(3)N_(4) nanosheets.In-situ FTIR spectroscopy demonstrated a stronger ability of CO_(2) activation to^ (∗)COOH on Sb/g-C_(3)N_(4) van der Waals heterostructure.As a result,the Sb/g-C_(3)N_(4) van der Waals heterostructures showed a higher CO yield with 2.03 umol g^(−1) h^(−1),which is 3.2 times that of pure g-C_(3)N_(4).This work provides a reference for activating CO_(2) and promoting CO_(2) reduction by van der Waals heterostructure.展开更多
Single-atom photocatalysts,due to their high catalysis activity,selectivity and stability,become a hotspot in the field of photocatalysis.Graphitic carbon nitride(g-C3N4)is known as both a good support for single atom...Single-atom photocatalysts,due to their high catalysis activity,selectivity and stability,become a hotspot in the field of photocatalysis.Graphitic carbon nitride(g-C3N4)is known as both a good support for single atoms and a star photocatalyst.Developing g-C3N4-based single-atom photocatalysts exhibits great potential in improving the photocatalytic performance.In this review,we summarize the recent progress in g-C3N4-based single-atom photocatalysts,mainly including preparation strategies,characterizations,and their photocatalytic applications.The significant roles of single atoms and catalysis mechanism in g-C3N4-based single-atom photocatalysts are analyzed.At last,the challenges and perspectives for exploring high-efficient g-C3N4-based single-atom photocatalysts are presented.展开更多
Advanced oxidation processes(AOPs)are promising technology to remove organic pollutant in water.However,the main problem in the AOPs is the low generation of hydroxyl radical(·OH)owing to the low decomposition ef...Advanced oxidation processes(AOPs)are promising technology to remove organic pollutant in water.However,the main problem in the AOPs is the low generation of hydroxyl radical(·OH)owing to the low decomposition efficiency of hydrogen peroxide(H_(2)O_(2)).Herein,the spinel type cobalt acid manganese(MnCo_(2)O_(4))with flower morphology was fabricated through a co-precipitation method.In situ Fourier transform infrared spectroscopy confirms that the MnCo_(2)O_(4) with the optimal molar ratio of Co and Mn precursors(CM3,Co:Mn=3)has more Lewis acid sites compared with single metal oxide catalysts(Co_(3)O_(4) and Mn_(2)O_(3)),leading to the excellent performances for H_(2)O_(2) decomposition rate constant on CM3,which is about 15.03 and 4.21 times higher than those of Co_(3)O_(4) and Mn_(2)O_(3),respectively.As a result,the obtained CM3 shows a higher ciprofloxacin degradation ratio than that of Co_(3)O_(4) and Mn_(2)O_(3).Furthermore,CM3 shows an excellent stability during several cycles.This work proposes effective catalysts for ciprofloxacin decomposition and provides feasible route for treating practical environmental problems.展开更多
文摘碱性析氢反应(HER)可将间歇性可再生能源转化为可存储的清洁能源,因而备受关注.然而,水解离速度缓慢以及H中间体(*H)吸附和解吸困难限制了碱性HER的进一步发展.目前,针对碱性电解水解离缓慢问题,通常采用调整电催化剂结构降低水分解热动力学能垒,以及改变三相界面微环境加速中间产物的扩散等方法来促进水分解进行.此外,可以通过调控活性位点电子结构来优化*H的吸脱附.但是采用单一的策略很难同时促进H_(2)O的解离和*H的吸脱附,难以获得令人满意的碱性HER性能.因此,探索一种能同时促进H_(2)O的解离和*H的吸脱附协同策略对提升碱性HER的性能至关重要.本文提出了一种协同策略,通过构建高曲率二硫化钴纳米针(CoS_(2)NNs)和原子级铜(Cu)的掺杂分别实现诱导纳米尺度的局域电场和原子尺度的电子局域化,从而促进碱性HER的H_(2)O解离和*H吸脱附.首先,采用有限元法模拟和密度泛函理论计算,从理论上分别证实了纳米尺度局域电场可以加速H_(2)O解离以及原子尺度电子局域化可以促进*H吸附.受理论计算结果启发,通过一步水热法和原位硫化相结合的方法制备了高曲率的Cu掺杂CoS_(2)纳米针(Cu-CoS_(2)NNs).采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和四探针测试等技术进行表征,研究了Cu-CoS_(2)NNs的形貌、物相结构、化学组成和导电性.结果表明,在Cu原子引入后,Cu-CoS_(2)NNs依然保持着高曲率的纳米针结构,证明了Cu在CoS_(2)NNs中的原子分散状态.相较于低曲率的Cu掺杂CoS_(2)纳米线(Cu-CoS_(2)NWs),Cu-CoS_(2)NNs只存在形貌上的区别,二者的化学组成和比例均非常接近.同时,上述材料都具有很强的导电性,且电导率基本相同,这与有限元模拟结果一致.原位衰减全反射红外光谱和电响应测试结果表明,Cu-CoS_(2)NNs具有较好的解离H_(2)O和吸附*H的能力.在1 mol L^(-1)KOH溶液和10 mA cm^(-2)电流密度下,该催化剂的析氢过电位仅为64 mV,展现出较好的电化学析氢性能.催化剂还表现出非常好的碱性析氢稳定性,在标准氢电势(RHE)-0.18 V下,可在100 mA cm^(-2)电流密度下稳定工作达100 h.综上所述,本文通过诱导局域电场和电子局域化构建了一种协同策略,所制备的Cu-CoS_(2)NNs表现出很好的催化碱性HER性能和应用前景,为碱性HER电催化剂的理性设计提供了一定的参考.
基金The authors gratefully thank the National Natural Science Foundation of China(No.22002189)Central South University Research Programme of Advanced Interdisciplinary Studies(No.2023QYJC012)+1 种基金Central South University Innovation-Driven Research Program(No.2023CXQD042)the Fundamental Research Funds for the Central Universities of Central South University(No.2023ZZTS0962).
文摘The use of gas diffusion electrode(GDE)based flow cell can realize industrial-scale CO_(2) reduction reactions(CO_(2)RRs).Controlling local CO_(2) and CO intermediate diffusion plays a key role in CO_(2)RR toward multi-carbon(C_(2+))products.In this work,local CO_(2) and CO intermediate diffusion through the catalyst layer(CL)was investigated for improving CO_(2)RR toward C_(2+)products.The gas permeability tests and finite element simulation results indicated CL can balance the CO_(2) gas diffusion and residence time of the CO intermediate,leading to a sufficient CO concentration with a suitable CO_(2)/H_(2)O supply for high C_(2+)products.As a result,an excellent selectivity of C_(2+)products~79%at a high current density of 400 mA·cm^(-2) could be obtained on the optimal 500 nm Cu CL(Cu500).This work provides a new insight into the optimization of CO_(2)/H_(2)O supply and local CO concentration by controlling CL for C_(2+)products in CO_(2)RR flow cell.
文摘电催化CO_(2)减排技术利用电能将过量的CO_(2)转化为有附加值的化学品,是解决能源危机、实现碳中和的有效途径之一.电催化CO_(2)还原反应(CO_(2)RR)中的多碳产物(C_(2)),如乙烯和乙醇,因其比C1产物具有更高的能量密度和更广泛的应用而受到较大关注.目前为止,Cu基催化剂被认为是获得C_(2)产物的独特材料.研究者在提高Cu基催化剂C_(2)产物的活性和选择性方面做了大量的工作,如催化剂形貌工程、活性位点设计和中间吸附性能调控等.许多理论和实验研究已经证明,Cu基催化剂上的C-C偶联过程是C_(2)产物生成的速率决定步骤.优化C-C偶联过程的能垒是提高C_(2)产物活性和选择性的重要而直接的策略.CO_(2)RR在Cu上是由CO_(2)还原吸附CO(*CO)并二聚生成C_(2)产物引起的.C-C偶联过程与*CO的吸附性能密切相关.众所周知,CO是一种典型的极性分子,因此其在催化剂表面的吸附性能可能会受到活性位点周围的局部电场的影响.构建合适的局部电场是调节CO吸附性能和C-C偶联过程的潜在手段之一.前期工作(Nature,2016,537,382-386)证明了高曲率金纳米针可以在尖端产生高的局部电场.高局域电场诱导K+聚集,使活性位点周围CO_(2)浓度升高,大大促进了Au纳米针上的CO生成.基于Au纳米针的局域电场促进了CO_(2)RR的CO生成.本文利用Cu纳米针促进并优化C-C偶联反应来提高C_(2)产物活性和选择性.结果表明,局部电场可以促进C-C偶联过程,进而增强CO_(2)电还原生成C_(2)产物.有限元模拟结果表明,高曲率铜纳米针处存在较强的局部电场;密度泛函理论计算结果表明,强电场能促进C-C耦合过程.在此基础上,制备了一系列不同曲率的Cu催化剂,其中,Cu纳米针(CuNNs)的曲率最高,Cu纳米棒(CuNRs)和Cu纳米颗粒(CuNPs)曲率次之.实验测得CuNNs上吸附的K+浓度最高,证明了纳米针上的局部电场最强.同时,CO吸附传感器测试表明,CuNNs对CO的吸附能力最强,原位傅里叶变换红外光谱显示,CuNNs的*COCO和*CO信号最强.由此可见,高曲率铜纳米针可以诱导高局部电场,从而促进C-C耦合过程.催化性能测试结果表明,在低电位(-0.6 V vs.RHE)下,Cu NNs对CO_(2)RR的生成C_(2)产物的法拉第效率值为44%,约为Cu NPs的2.2倍.综上,本文为CO_(2)RR过程中提高多碳产物提供了新的思路.
基金the National Natural Science Foundation of China(21872174,22002189,U1932148)the International Science and Technology Cooperation Program(2017YFE0127800,2018YFE0203402)+5 种基金the Hunan Provincial Science and Technology Program(2017XK2026)the Hunan Province Key Field R&D Program(2020WK2002)the Hunan Provincial Natural Science Foundation of China(2020JJ2041,2020JJ5691)the Shenzhen Science and Technology Innovation Project(JCYJ20180307151313532)the Fundamental Research Funds for the Central Universities of Central South University。
文摘Copper (Cu) is a special electrocatalyst for CO_(2) reduction reaction (CO_(2)RR) to multi-carbon products.Experimentally introducing grain boundaries (GBs) into Cu-based catalysts is an efficient strategy to improve the selectivity of C^(2+) products.However,it is still elusive for the C^(2+) product generation on Cu GBs due to the complex active sites.In this work,we found that the tandem catalysis pathway on adjacent active motifs of Cu GB is responsible for the enhanced activity for C^(2+)production by first principles calculations.By electronic structure analysis shows,the d-band center of GB site is close to the Fermi level than Cu(100) facet,the Cu atomic sites at grain boundary have shorter bond length and stronger bonding with*CO,which can enhance the adsorption of*CO at GB sites.Moreover,CO_(2)protonation is more favorable on the region Ⅲ motif (0.84 e V) than at Cu(100) site (1.35 e V).Meanwhile,the region Ⅱ motif also facilitate the C–C coupling (0.72 e V) compared to the Cu(100) motif (1.09 e V).Therefore,the region Ⅲ and Ⅱ motifs form a tandem catalysis pathway,which promotes the C^(2+)selectivity on Cu GBs.This work provides new insights into CO_(2)RR process.
基金the National Postdoctoral Program for Innovative Talents of China,Postdoctoral Science Foundation of China(Grant No.2018M640759)Natural Science Foundation of China(Grant No.21872174 and U1932148)+4 种基金Project of Innovation-Driven Plan in Central South University(Grant No.20180018050001)State Key Laboratory of Powder Metallurgy,International Science and Technology Cooperation Program(Grant No.2017YFE0127800)Hunan Provincial Science and Technology Program(2017XK2026)Shenzhen Science and Technology Innovation Project(Grant No.JCYJ20180307151313532)Thousand Youth Talents Plan of China and Hundred Youth Talents Program of Hunan.
文摘Converting carbon dioxide(CO2)into value-added chemicals by CO2 reduction has been considered as a potential way to solve the current energy crisis and environmental problem.Among the methods of CO2 reduction,the electrochemical method has been widely used due to its mild reaction condition and high reaction efficiency.In the electrochemical reduction system,the CO2 electrocatalyst is the most important part.Although many CO2 electrocatalysts have been developed,efficient catalysts with high activity,selectivity and stability are still lacking.Copper sulfide compound,as a low-toxicity and emerging material,has broad prospects in the field of CO2 reduction due to its unique structural and electrochemical properties.Much progress has been achieved with copper sulfide nanocrystalline and the field is rapidly developing.This paper summarizes the preparation,recent progress in development,and factors affecting the electrocatalytic CO2 reduction performance with copper sulfide compound as a catalyst.Prospects for future development are also outlined,with the aim of using copper sulfide compound as a highly active and stable electrocatalyst for CO2 reduction.
基金the International Science and Technology Cooperation Program(2017YFE0127800 and 2018YFE0203400)the Natural Science Foundation of China(21872174,21762036 and U1932148)+7 种基金the Hunan Provincial Science and Technology Program(2017XK2026)the Shenzhen Science and Technology Innovation Project(JCYJ20180307151313532)Innovation and Entrepreneurship Training Program for College Students(S202110670023)the Natural Science Foundation of Science and Technology Department of Guizhou Province([2019]1297)the Special Project of Science and Technology Department of Guizhou Province([2020]QNSYXM03)the Natural Science Foundation of Education Department of Guizhou Province([2019]213,[2015]66)Teaching Quality Improvement Project of Qiannan Normal University for Nationalities([2017]50)the Beam Lines of BL01C1,BL24A1 in the NSRRC(MOST 109-2113-M-213-002)and beamline BL10B in National Synchrotron Radiation Laboratory。
文摘Now,Pt-based materials are still the best catalysts for hydrogen evolution reaction(HER).Nevertheless,the scarcity of Pt makes it impossible for the large-scale applications in industry.Although cobalt is taken as an excellent HER catalyst due to its suitable H*binding,its alkali HER catalytic property need to be improved because of the sluggish water dissociation kinetics.In this work,nitrogen with small atomic radius and metallophilicity is employed to adjust local charges of atomically dispersed Mo^(δ+)sites on Co nanosheets to trigger water dissociation.Theoretical calculations suggest that the energy barrier of water dissociation can be effectively reduced by introducing nitrogen coordinated Mo^(δ+)sites.To realize this speculation,atomically dispersed Mo^(δ+)sites with nitrogen coordination of Mo(N)/Co were prepared via reconstruction of CoMoO_(4).High angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)and X-ray absorption spectroscopy(XAS)demonstrate the coordination of N atoms with atomically dispersed Mo atoms,leading to the local charges of atomically dispersed Mo^(δ+)sites in Mo(N)/Co.The measurement from ambient pressure X-ray photoelectron spectroscopy(AP-XPS)reveals that the Mo^(δ+)sites promote the adsorption and activation of water molecule.Therefore,the Mo(N)/Co exhibits an excellent activity,which need only an overpotential of 39 mV to reach the current density of 10 mA cm^(-2).The proposed strategy provides an advance pathway to design and boost alkaline HER activity at the atomic-level.
基金Natural Science Foundation of China (21872174,22002189,U1932148)the International Science and Technology Cooperation Program (2017YFE0127800,2018YFE0203402)+5 种基金the Hunan Provincial Science and Technology Program(2017XK2026)the Hunan Province Key Field R&D Program(2020WK2002)the Hunan Provincial Natural Science Foundation of China (2020JJ2041,2020JJ5691)the Shenzhen Science and Technology Innovation Project (JCYJ20180307151313532)the Hunan Provincial Science and Technology Plan Project(2017TP1001)the Fundamental Research Funds for the Central Universities of Central South University。
文摘Formate is an important liquid chemical,which can be produced by electrocatalytic carbon dioxide reduction reaction(CO_(2) RR).Most of the metal catalysts for CO_(2) RR to formate are toxic or noble metals,such as Cd,Hg,Pb and Pd,leading to the environmental pollution or increased production costs.Herein,we develop an environmentally friendly and low-cost NiZn alloy catalyst for CO_(2) RR to formate.The X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM) confirm the alloy structure of the prepared NiZn catalyst. As for a catalyst for CO_(2) RR,the NiZn alloy exhibits the FE_(HCOO)^(-)(Faraday efficiency of HCOO^(-)) of 36±0.7% at-0.9 V vs.RHE in 0.1 M KHCO_(3), and remarkable stability for 40,000 s at-0.8,-0.9,-1.0 and-1.1 V vs.RHE,respectively.Theoretical calculation results indicate that the NiZn alloy exhibits the middle valence electron structure between the Zn and Ni metal,resulting in the favorable pathway for HCOOH formation but unfavorable for the hydrogen evolution reaction and CO production.The Ultraviolet Photoelectron Spectroscopy results verify the modulated valence electron structure for NiZn alloy as compared to Ni and Zn,consistent with the theoretical calculation results.This work provides new insights into design of alloy catalysts for CO_(2) RR to formate.
基金supported by the National Key R&D Program of China(2022YFE0126500)the National Natural Science Foundation of China(22278169,22150610467,52372253,51973078)+6 种基金the Excellent Scientific Research and Innovation Team of the Education Department of Anhui Province(2022AH010028)the Major projects of Education Department of Anhui Province(2022AH040068)the Key Foundation of Educational Commission of Anhui Province(2022AH050396,2022AH050376)Anhui Provincial Quality Engineering Project(2022sx13)the Innovation Fund for Postgraduates of Huaibei Normal University(CX2023038)Surplus Funds to Expand Research Projects of Huaibei Normal University(2023ZK045)the Open Project from the Key Laboratory of Green and Precise Synthetic Chemistry and Applications(2020KF07)。
基金This work was supported by Natural Science Foundation of China(Nos.81903770,81973177,and 22277110,China)Joint Funds of Technology Research and Development Plan of Henan Province(No.232301420058,China)+5 种基金China Postdoctoral Science Foundation(No.2019M662556,China)Key scientific and technological projects of Henan Province(No.222102310125,China)Natural Science Foundation of Henan Province(No.222300420069,China)Program for Science&Technology Innovation Talents in Universities of Henan Province(No.21HASTIT045,China)Cultivation Project of Zhengzhou University(JC23852097,China)Tianjian Laboratory of Advanced Biomedical Sciences,and the open fund of State Key Laboratory of Pharmaceutical Biotechnology,Nanjing University,China(No.KF-202303,China).
文摘Histone methylation plays crucial roles in regulating chromatin structure and gene transcrip-tion in epigenetic modifications.Lysine-specific demethylase 1(LSD1),the first identified histone de-methylase,is universally overexpressed in various diseases.LSD1 dysregulation is closely associated with cancer,viral infections,and neurodegenerative diseases,etc.,making it a promising therapeutic target.Several LSD1 inhibitors and two small-molecule degraders(UM171 and BEA-17)have entered the clinical stage.LSD1 can remove methyl groups from histone 3 at lysine 4 or lysine 9(H3K4 or H3K9),resulting in either transcription repression or activation.While the roles of LSD1 in transcrip-tional regulation are well-established,studies have revealed that LSDl can also be dynamically regulated by other factors.For example,the expression or activity of LSD1 can be regulated by many proteins that form transcriptional corepressor complexes with LSD1.Moreover,some post-transcriptional modifica-tions and cellular metabolites can also regulate LSD1 expression or its demethylase activity.Therefore,in this review,we will systematically summarize how proteins involved in the transcriptional corepressor complex,various post-translational modifications,and metabolites act as regulatory factors for LSD1 ac-tivity.
文摘To suppress the recombination of photogenerated electron and hole in single photocatalysts,an important method is to design heterojunction by combining two photocatalysts.This method has widely used to enhance the photocatalytic performance of the composites.At the begining,most people use type-Ⅱcharge carrier transfer mechanism to explain the emhanced activity of the composite semiconductors.
基金supported by National Natural Science Foundation of China(Nos.22002189 and 51973078)the Open Project from Key Laboratory of Green and Precise Synthetic Chemistry and Applications(No.2020KF07)+1 种基金the Distinguished Young Scholar of Anhui Province(No.1808085J14)the Key Foundation of Educational Commission of Anhui Province(Nos.KJ2019A0595 and KJ2020ZD005)。
文摘Photocatalytic reduction of CO_(2) into valuable fuels is one of the potential strategies to solve the carbon cycle and energy crisis.Graphitic carbon nitride(g-C_(3)N_(4)),as a typical two-dimensional(2D)semiconductor with a bandgap of∼2.7 eV,has attracted wide attention in photocatalytic CO_(2) reduction.However,the performance of g-C_(3)N_(4) is greatly limited by the rapid recombination of photogenerated charge carriers and weak CO_(2) activation capacity.Construction of van der Waals heterostructure with the maximum interface contact area can improve the transfer/seperation efficiency of interface charge carriers.Ultrathin metal antimony(Sb)nanosheet(antimonene)with high carrier mobility and 2D layered structure,is a good candidate material to construct 2D/2D Sb/g-C_(3)N_(4) van der Waals heterostructure.In this work,the density functional theory(DFT)calculations indicated that antimonene has higher carrier mobility than g-C_(3)N_(4) nanosheets.Obvious charge transfer and in-plane structure distortion will occur at the interface of Sb/g-C_(3)N_(4),which endow stronger CO_(2) activation ability on di-coordinated N active site.The ultrathin g-C_(3)N_(4) and antimonene nanosheets were prepared by ultrasonic exfoliation method,and Sb/g-C_(3)N_(4) van der Waals heterostructures were constructed by self-assembly process.The photoluminescence(PL)and time-resolved photoluminescence(TRPL)indicated that the Sb/g-C_(3)N_(4) van der Waals heterostructures have a better photogenerated charge separation efficiency than pure g-C_(3)N_(4) nanosheets.In-situ FTIR spectroscopy demonstrated a stronger ability of CO_(2) activation to^ (∗)COOH on Sb/g-C_(3)N_(4) van der Waals heterostructure.As a result,the Sb/g-C_(3)N_(4) van der Waals heterostructures showed a higher CO yield with 2.03 umol g^(−1) h^(−1),which is 3.2 times that of pure g-C_(3)N_(4).This work provides a reference for activating CO_(2) and promoting CO_(2) reduction by van der Waals heterostructure.
基金This work was supported by the National Postdoctoral Program for Innovative Talents of China,China Postdoctoral Science Foundation(No.2018M640759)the National Natural Science Foundation of China(Grant Nos.21872174 and U1932148)+5 种基金the Project of Innovation-Driven Plan in Central South University(No.20180018050001)the International S&T Cooperation Program of China(No.2017YFE0127800)Hunan Provincial Science and Technology Program(No.2017XK2026)State Key Laboratory of Powder Metallurgy,Shenzhen Science and Technology Innovation Project(No.JCYJ20180307151313532)the Hunan Provincial Science and Technology Plan Project(No.2017TP1001)Thousand Youth Talents Plan of China and Hundred Youth Talents Program of Hunan.
文摘Single-atom photocatalysts,due to their high catalysis activity,selectivity and stability,become a hotspot in the field of photocatalysis.Graphitic carbon nitride(g-C3N4)is known as both a good support for single atoms and a star photocatalyst.Developing g-C3N4-based single-atom photocatalysts exhibits great potential in improving the photocatalytic performance.In this review,we summarize the recent progress in g-C3N4-based single-atom photocatalysts,mainly including preparation strategies,characterizations,and their photocatalytic applications.The significant roles of single atoms and catalysis mechanism in g-C3N4-based single-atom photocatalysts are analyzed.At last,the challenges and perspectives for exploring high-efficient g-C3N4-based single-atom photocatalysts are presented.
基金the International Science and Technology Cooperation Program(Nos.2017YFE0127800 and 2018YFE0203400)National Natural Science Foundation of China(Nos.21872174,22002189 and U1932148)+3 种基金Hunan Provincial Science and Technology Program(Nos.2017XK2026 and 2017TP1001)Hunan Provincial Natural Science Foundation(Nos.2020JJ2041,2020JJ5691 and 2021JJ30864)Key R&D Program of Hunan Province(No.2020WK2002)Shenzhen Science and Technology Innovation Project(No.JCYJ20180307151313532).
文摘Advanced oxidation processes(AOPs)are promising technology to remove organic pollutant in water.However,the main problem in the AOPs is the low generation of hydroxyl radical(·OH)owing to the low decomposition efficiency of hydrogen peroxide(H_(2)O_(2)).Herein,the spinel type cobalt acid manganese(MnCo_(2)O_(4))with flower morphology was fabricated through a co-precipitation method.In situ Fourier transform infrared spectroscopy confirms that the MnCo_(2)O_(4) with the optimal molar ratio of Co and Mn precursors(CM3,Co:Mn=3)has more Lewis acid sites compared with single metal oxide catalysts(Co_(3)O_(4) and Mn_(2)O_(3)),leading to the excellent performances for H_(2)O_(2) decomposition rate constant on CM3,which is about 15.03 and 4.21 times higher than those of Co_(3)O_(4) and Mn_(2)O_(3),respectively.As a result,the obtained CM3 shows a higher ciprofloxacin degradation ratio than that of Co_(3)O_(4) and Mn_(2)O_(3).Furthermore,CM3 shows an excellent stability during several cycles.This work proposes effective catalysts for ciprofloxacin decomposition and provides feasible route for treating practical environmental problems.
