摘要：Oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)are the key processes in water *** with the two-electron process in HER,the four-electron process of OER is slow because of the more complex series of ***,a good understanding of the direct O_(2) evolution mechanism(DOEM)in OER is crucial to design high-efficiency catalysts to overcome the limitations imposed by the conventional adsorption evolution *** this work,honeycomb Ni_(3)N-Co_(3)N was prepared on carbon cloth(Ni_(3)N-Co_(3)N/CC)to investigate the *** functional theory and in situ Raman scattering spectroscopy demonstrated that the OER process on Ni_(3)N-Co_(3)N/CC proceeded via the DOEM pathway,in which Ni_(3)N and Co_(3)N share the roles of dragging OH^(-),splitting off H-O bonds,and adsorbing other OH^(-),leading to significantly reduced Gibbs’s energy barriers of ΔG_(*OH) to ΔG_(O*)and ΔG_(O*)to ΔG_(O*OH).Moreover,the vertical honeycomb structure and conductive CC substrate contributed to the structural stability,conductivity,and quick O_(2) release *** Ni_(3)N-Co_(3)N/CC required low overpotentials of 320 and 495 mV to reach a current density of 10 and 100 mA cm^(-2),***,the Ni_(3)N-Co_(3)N/CC delivered excellent stability with>90% retention of the initial current density over an 80-h-long test.

摘要：The design and construction of highly effective circularly polarized luminescence(CPL)-active materials has aroused considerable attention due to their widespread applications in sensors,optical devices,and asymmetric ***,the exploration of novel CPL-active materials with high luminescence dissymmetry factor(glum)values is still a ***,we describe a new approach for the preparation of supramolecular metallacycles with amplified CPL promoted by hierarchical self-assembly involving Pt···Pt ***,the resultant metallacycles exhibited strong CPL signals with high glum values,while their corresponding precursors were CPL *** CPL amplification mechanism was comprehensively validated by ultravioletvisible absorption,emission spectroscopy,nuclear magnetic resonance spectroscopy,scanning electron microscopy,transmission electron microscopy,atomic force microscopy,coarse-grained molecular dynamics simulations,and timedependent density functional theory *** work thus provides the first example of preparing highly effective CPL-active materials based on hierarchical self-assembly involving Pt···Pt interactions.

摘要：Catalytic hydrogenation is a vital industrial means to produce value-added fuels and fine chemicals,however, requiring highly efficient catalysts, especially the nonprecious ones. To date, the majority of high-performance industrial hydrogenation catalysts are made of precious metals-based materials, and any given catalyst could only be used to catalyze one or few specific reactions. Herein, we exemplify a crystal phase engineering approach to empower Ni nanoparticles(NPs) with superb intrinsic catalytic activities toward a wide spectrum of hydrogenation reactions. A facile pyrolysis approach is used to directly convert a Ni-imidazole MOF precursor into hexagonal close-packed(hcp)-phased Ni NPs on carbon support. The as-synthesized hcp-phased Ni NPs exhibit unprecedented hydrogenation catalytic activities in pure water towards nitro-, aldehyde-, ketone-, alkene-and N heterocyclic-compounds, outperforming the face-centered cubic(fcc)-Ni counterpart and the reported transition metalsbased catalysts. The density functional theory calculations unveil that the presence of hcp-Ni boosts the intrinsic catalytic hydrogenation activity by coherently enhancing the substrate adsorption strength and lowering the reaction barrier energy of the rate-determining step. We anticipate that the crystal phase engineering design approach unveiled in this work would be adoptable to other types of reactions.

摘要：A new complementary metal oxide semiconductor UV/blue-extended photodiode was presented for light detection in the UV/blue spectral range. Photoelectric characteristics of this presented photodiode were studied by numerical modeling and device simulation. Technology computer aided design simulation was done first to analyze its photoelectric characteristics. The structure characteristic and depletion situation of space between two adjacent P+ anodes were discussed. The reverse characteristic, spectral response characteristic and DC characteristic were discussed in detail. For the numerical modeling, dead layer effect is considered in the building of analytical mode. Dead layer is a space in which the boron doping profile decreases towards the surface due to high doping effects and boron redistribution, which affects the sensitivity of photodiode in the UV range seriously. Reverse characteristics and spectral response characteristics were modeled and analyzed typically. At last, silicon test results were given and compared with the simulated result, which shows reasonable match for each.

摘要：水系钾基电池(APBs)因具有高安全性和环境友好的性质而被广泛研究.然而,由于电极材料和工作机制的限制,APBs在倍率性能和能量密度方面需要进一步提高,以满足发展需求.针对上述问题,我们首次成功设计并组装了以Z n金属作为阳极,K1.9 2C u0.6 2M n0.3 8-[Fe(CN)6]0.968·□0.0 3 2·H_(2)O0.35作为阴极,2 mol L-1Zn(SO_(3)CF3)2+12 mol L-1KSO_(3)CF3作为电解液的水系钾基电池.这种混合离子体系的设计优点是:(i)选择金属锌作为阳极,提高了APBs的工作电位;(ii)双阳离子储存机制缩短了离子传输路径;(ⅲ)来自双阳离子电解质的K+通过静电屏蔽作用抑制了锌枝晶的生长.因此,组装后的全电池具有1.75 V的高工作电位,并具有优异的倍率性能(在10,000 mA g-1的电流密度下,保持原有容量的83.3%).此外,通过理论相场模拟和综合表征充分揭示了原位静电屏蔽效应,显著抑制了锌阳极的枝晶生长,提高了全电池稳定性.混合离子电池的结构设计为高性能APBs的发展提供了思路.

摘要：拓宽材料对光子的吸收是利用太阳光能的关键.然而,要平衡电极材料对光的最大化吸收与存储是当前光电极材料的设计难点.本文报道了一种具有丰富硫空位的Cu_(2)S/CuCl异质阵列材料,该材料中CuCl与硫空位的存在增加了其对光子的捕获与转化.同时,Cu_(2)S/CuCl异质结增加了材料的导电性能,促进了电子的传输效率.当作为赝电容的电极材料时,该Cu_(2)S/CuCl双功能材料的光照下容量提升比率高达35%.同时,由该材料制成的非对称电容器循环测试6000次之后的面积比容量可依旧维持在670 mF cm^(-2).该Cu_(2)S/CuCl材料具有优异的光电化学性能,在下一代光辅助充电储能器件的应用领域展示出巨大前景.

摘要：Single-atom catalysts(SACs)have been widely used in heterogeneous catalysis owing to the maximum utilization of metal-active sites with controlled structures and well-defined *** tailored coordination with nitrogen atom,the metal-nitrogen(M-N)-based SACs have demonstrated interesting physical,optical and electronic properties and have become intense in photocatalysis and electrocatalysis in the past *** substantial efforts in constructing various M–N-based SACs,the principles for modulating the intrinsic photocatalytic and electrocatalytic performance of their active sites and catalytic mechanism have not been sufficiently ***,the present review intends to shed some light on recent research made in studying the correlation between intrinsic electronic structure,catalytic mechanism,single-metal atom(SMA)confinement and their photocatalytic and electrocatalytic activities(conversion,selectivity,stability and etc).Based on the analysis of fundamentals of M–N-based SACs,theoretical calculations and experimental investigations,including synthetic methods and characterization techniques,are both included to provide an integral understanding of the underlying mechanisms behind improved coordination structure and observed ***,the challenges and perspectives for constructing highly active M–N based photocatalysis and electrocatalysis SACs are *** particular,extensive technical and mechanism aspects are thoroughly discussed,summarized and analyzed for promoting further advancement of M-N-based SACs in photocatalysis and electrocatalysis.

摘要：我们设计并制备了一种基于LiGa_(4)(MgGe)_(0.5)O_(8):Cr荧光粉变温发光特性的柔性温度传感光纤.通常来说,随着温度的升高,发光材料基质的电子-声子作用将加剧,这会导致其发射峰的半高宽(FWHM)在升温时不断加宽.在本工作中,随着LiGa_(5-x)(MgGe)_(x)O_(8):Cr中[Mg^(2+)-Ge^(4+)]化学单元成分比例的增加,荧光粉近红外发光的FWHM出现明显展宽,其外量子效率也从24.8%增加到50.0%.进一步研究发现,LiGa_(4)-(MgGe)_(0.5)O_(8):Cr纳米荧光粉的发光具有优异的热稳定性和温度传感特性,在443 K时绝对灵敏度可达7.51 cm^(-1)K^(-1),303 K下相对灵敏度为0.64%K^(-1).基于此,我们搭建了具有可重复性、高精度和优异稳定性的柔性全光纤系统,并将其用于实时监测物体的温度.本研究不仅探索了具有锐线发射的Cr^(3+)掺杂发光材料的应用,而且丰富了基于荧光材料带宽特性的光学测温新思路.

摘要：Photocatalytic hydrogen production represents a promising strategy for clean, sustainable, and environmentfriendly energy supply. Up to now, great efforts have been devoted to designing the photocatalysts with noble metal as co-catalyst for visible-light-driven hydrogen evolution, while more efficient photocatalytic systems are still a major challenge. Herein, we report a facile strategy for synthesizing faceto-face ultrathin Pd nanosheets-amorphous carbon nitride(Pd NSs-ACN) structure with large contacting interface and short electronic transmission pathway, which can work as an efficient photocatalyst for hydrogen production. The synthesis starts with the growth of ultrathin Pd NSs, followed by assembly with the visible-light-response ACN through a simple stirring and annealing procedure. The resultant two dimensional face-to-face structures deliver an average hydrogen generation rate of 1.45 mmol h-1g-1 at a temperature of 25℃,almost 2.6 times higher than that of Pd Nps-ACN with particle-to-face structural feature. The efficient photocatalytic activity is ascribed to the formation of high-density of active sites between ultrafine face-to-face contacted Pd NSs and the ACN, which cooperate more synergistically towards photocatalytic hydrogen production. The face-to-face engineered Pd NSs-ACN hybrids also offer a good stability revealed by photocatalytic hydrogen production measurements. The extraordinary performance highlights a powerful engineering model for designing other face-to-face contacting co-catalyst/photocatalysts, which will be a great impetus to optimize new catalytic transformations.

摘要：Biodegradable Mg-Zn alloy was synthesized using mechanical alloying where a statistical model was developed using fractional factorial design to predict elastic modulus and mass loss of the bulk *** effects of mechanical alloying parameters(i.e.,milling time,milling speed,ball-to-powder mass ratio and Zn content)and their interactions were investigated involving 4 numerical factors with 2 replicates,thus 16 runs of two-level fractional factorial *** of analysis of variance(ANOVA),regression analysis and R2 test indicated good accuracy of the *** statistical model determined that the elastic modulus of biodegradable Mg-Zn alloy was between 40.18 and 47.88 GPa,which was improved and resembled that of natural bone(30-57 GPa).Corrosion resistance(mass loss of pure Mg,33.74 mg)was enhanced with addition of 3%-10%Zn(between 9.32 and 15.38 mg).The most significant independent variable was Zn content,and only the interaction of milling time and ball-to-powder mass ratio was significant as P-value was less than ***,mechanical properties(represented by elastic modulus)and corrosion resistance(represented by mass loss)of biodegradable Mg-Zn alloy can be statistically predicted according to the developed models.