Synergism of Interface and Electronic Effects: Bifunctional N-Doped Ni3S2/N-Doped MoS2 Hetero-Nanowires for Efficient Electrocatalytic Overall Water Splitting

The realization of water electrolysis on the basis of highly active, cost-effective electrocatalysts is significant yet challenging for achieving sustainable hydrogen production from water. Herein, N-doped Ni₃S₂/N-doped MoS₂ 1D hetero-nanowires supported by Ni foam (N-Ni₃S₂/N-MoS₂/NF) are readily synthesized through a chemical transformation strategy by using NiMoO₄ nanowire array growth on Ni foam (NiMoO₄/NF) as the starting material. With the in situ generation of Ni₃S₂/MoS₂ heterointerfaces within nanowires and the incorporation of N⁻ anions, an extraordinary hydrophilic nature with abundant, well-exposed active sites and optimal reaction dynamics for both oxidation and reduction of water are obtained. Attributed to these properties, as-converted N-Ni₃S₂/N-MoS₂/NF exhibits highly efficient electrocatalytic activities for both hydrogen and oxygen evolution reactions under alkaline conditions. The superior bifunctional properties of N-Ni₃S₂/N-MoS₂/NF enable it to effectively catalyze the overall water-splitting reaction.     

A new MnxOy/carbon nanorods derived from bimetallic Zn/Mn metal–organic framework as an efficient oxygen reduction reaction electrocatalyst for alkaline Zn-Air batteries

Journal of Solid State Electrochemistry - In this work, nanorods like bimetallic Zn/Mn metal–organic-frameworks (MOFs) are proposed as the precursor for preparing MnxOy/porous carbon...     

A Lysosome‐Compatible Near‐Infrared Fluorescent Probe for Targeted Monitoring of Nitric Oxide

The requirement for nitric oxide (NO) of lysosomes has motivated the development of a sophisticated fluorescent probe to monitor the distribution of this important biomolecule at the subcellular level in living cells. A near‐infrared (NIR) fluorescent Si‐rhodamine (SiRB)‐NO probe was designed based on the NO‐induced ring‐opening process of Si‐rhodamine. The probe exhibits fast chromogenic and fluorogenic responses, and high sensitivity and selectivity toward trace amounts of NO. Significantly, the spirolactam in Si‐rhodamine exhibits very good tolerance to H⁺, which in turn brings extremely low background fluorescence not only in the physiological environment but also under acidic conditions. The stability of the highly fluorescent product in acidic solution provides persistent fluorescence emission for long‐term imaging experiments. To achieve targeted imaging with improved spatial resolution and sensitivity, an efficient lysosome‐targeting moiety was conjugated to a SiRB‐NO probe, affording a tailored lysosome‐targeting NIR fluorescent Lyso‐SiRB‐NO probe. Inheriting the key advantages of its parent SiRB‐NO probe, Lyso‐SiRB‐NO is a functional probe that is suited for monitoring lysosomal NO with excellent lysosome compatibility. Imaging experiments demonstrated the monitoring of both exogenous and endogenous NO in real time by using the Lyso‐SiRB‐NO probe.     

Synthesis,crystal structure,spectroscopic properties and DFT calculations of a new Schiff base-type Zinc(II) complex

Research on Chemical Intermediates - A new mononuclear Zn(II) complex, [Zn(L 2 )2]·CH3OH (HL 2  = 1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime),...     

Enhancing Built-in Electric Fields for Efficient Photocatalytic Hydrogen Evolution by Encapsulating C60 Fullerene into Zirconium-Based Metal-Organic Frameworks

High-efficiency photocatalysts based on metal-organic frameworks (MOFs) are often limited by poor charge separation and slow charge-transfer kinetics. Herein, a novel MOF photocatalyst is successfully constructed by encapsulating C₆₀ into a nano-sized zirconium-based MOF, NU-901. By virtue of host-guest interactions and uneven charge distribution, a substantial electrostatic potential difference is set-up in C₆₀@NU-901. The direct consequence is a robust built-in electric field, which tends to be 10.7 times higher in C₆₀@NU-901 than that found in NU-901. In the catalyst, photogenerated charge carriers are efficiently separated and transported to the surface. For example, photocatalytic hydrogen evolution reaches 22.3 mmol g⁻¹ h⁻¹ for C₆₀@NU-901, which is among the highest values for MOFs. Our concept of enhancing charge separation by harnessing host-guest interactions constitutes a promising strategy to design photocatalysts for efficient solar-to-chemical energy conversion.     

Self-assembled lamellar nanochannels in polyoxometalate-polymer nanocomposites for proton conduction

The construction of nanostructured ion-transport channels is highly desirable in the design of advanced electrolyte materials,as it can enhance ion conductivity by offering short ion-transport pathways.In this work,we present a supramolecular strategy to fabricate a nanocomposite electrolyte containing highly ordered lamellar proton-conducting nanochannels,by the electrostatic self-assembly of a polyoxometalate H_3 PW_(12)O_(4 O)(PW) and a comb copolymer poly(4-methlstyrene)-graft-poly(N-vinyl pyrrolidone).PW can effectively regulate the self-assembling order of polymer moieties to form a large-ra nge lamellar structure,meanwhile,introducing protons into the nanoscale lamellar domains to build proton transport channels.Moreover,the rigid PW clusters contribute a remarkable mechanical reinforcement to the nanocomposites.The lamellar nanocomposite exhibits a conductivity of 4.3 × 10~(-4) S/cm and a storage modulus of 1.1 × 10~7 Pa at room temperature.This study provides a new strategy to construct nanostructured ion-conductive pathways in electrolyte materials.     

Nb掺杂调控CoSeS多级纳米结构用于增强析氢反应

电催化析氢(HER)是清洁制氢的一种有效途径,对于氢经济和氢能产业的发展具有重要意义.金属掺杂是提高电催化剂本征活性的有效方法,导电基底的采用也有利于电荷传输和催化性能的整体提高.尽管已有关于硒化物作为HER催化剂的相关报道,但是合成条件有限、导电性、本征活性的影响,其电催化性能仍有提升的空间.此外,在酸性电解液中的腐蚀和氧化极大限制了催化剂性能的发挥.基于此,本文以氮掺杂碳球为载体,采用金属Nb掺杂、非金属硫硒化物协同以及表面碳包覆的三重策略,将掺杂元素Nb和活性位中心元素Co封装到氮掺杂碳纳米球内并进行连续的硫硒化反应,成功构筑多级纳米结构(Nb-CoSeS@NC)以提高其电催化析氢性能.碳球可为活性位的生长和分散提供足够的空间,同时有效防止活性金属的腐蚀和分解,并阻止金属纳米颗粒的团聚.硫化过程实现了非金属硫元素的掺杂,对于提高硒化物的催化活性和导电性都有重要作用.通过扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)、拉曼光谱、X射线光电子能谱(XPS)及电催化性能测试,详细研究了Nb-CoSeS@NC独特的纳米结构和电催化制氢性能,并分析了构效关系.XRD结果发现,引入Nb后Co9Se8和CoSe的特征峰移向更高的角度,表明其晶格体积的减小,有助于电荷传输.同时,氮掺杂碳球(NC)在26°可以观察到无定型碳的峰,而石墨碳的D带和G带强度比约为1.05,均表明NC中缺陷的存在,这可以进一步提高碳材料的导电性.SEM和TEM表征显示,催化剂为直径120 nm的均匀的纳米核壳结构,壳层约为30 nm,无明显的团聚和破碎,这是催化剂具有高稳定性的重要原因.表面的褶皱保证了大的活性比表面积,可以大大增加活性位点的数量.同时,催化剂与NC之间的紧密结合可以降低电子传输的阻抗进而改善其稳定性和析氢性能.分析高分辨率的TEM结果发现,Nb掺杂后,Nb-CoSeS@NC中Co₉Se₈的(222)晶面由0.301 nm减小至0.184 nm,与XRD结果相符.XPS表征揭示了引入Nb之后的电子效应.与CoSeS@NC相比,Nb的掺杂使Co 2p向更低的结合能移动,而Se 3d则移向高结合能移动,这是由于Nb导致了更强的电子相互作用.在0.5 M的H₂SO₄中测试催化剂的析氢性能,Nb-CoSeS@NC仅需115 mV的过电位便可以实现10 mA cm^-2的电流密度,Tafel斜率为43 mV dec^-1,优于CoSeS@NC等其他对比样品,且优于大多数掺杂型硒化物电催化剂.经过12 h稳定性测试,电流密度未见明显降低,表明该多级结构催化剂的优异稳定性.Nb-CoSeS@NC提高活性可归因为Nb的掺杂增强了催化剂的电子相互作用,有助于提高的其本征导电性.Nb、Co正离子可以形成氢化物-受体中心,可能会削弱S-H键和Se-H键,并促进H-H键的形成,因此,多元掺杂产生的协同效应可以有效促进HER过程.此外,坚固的氮掺杂纳米碳壳为活性位点的分散提供了足够的空间和优异的电荷传输性能,同时降低了金属活性位腐蚀的可能性.     

Cu Doping-Induced Transformation from [Ag62S12(SBut)32]2+ to [Ag62−xCuxS12(SBut)32]4+ Nanocluster

The change in the valence state of nanocluster can induce remarkable changes in the properties and structure. However, achieving the valence state changes in nanoclusters is still a challenge. In this work, we use Cu²⁺ as dopant to “oxidize” [Ag₆₂S₁₂(SBu^t)₃₂]²⁺ (4 free electrons) to obtain the new nanocluster: [Ag_62−xCu_xS₁₂(SBu^t)₃₂]⁴⁺ with 2 free electrons. As revealed by its structure, the [Ag_62−xCu_xS₁₂(SBu^t)₃₂]⁴⁺ (x=10∼21) has a similar structure to that of [Ag₆₂S₁₂(SBu^t)₃₂]²⁺ precursor and all the Cu atoms occupy the surface site of nanocluster. It′s worth noting that with the Cu atoms doping, the [Ag_62−xCu_xS₁₂(SBu^t)₃₂]⁴⁺ nanocluster is more stable than [Ag₆₂S₁₂(SBu^t)₃₂]²⁺ at higher temperature and in electrochemical cycle. This result has laid a foundation for the subsequent application and exploration. Overall, this work reveals crystals structure of a new Ag−Cu nanocluster and offers a new insight into the electron reduction/oxidation of nanocluster.