Defects‑Rich Heterostructures Trigger Strong Polarization Coupling in Sulfides/Carbon Composites with Robust Electromagnetic Wave Absorption

Defects-rich heterointerfaces integrated with adjustable crystalline phases and atom vacancies,as well as veiled dielectric-responsive character,are instrumental in electromagnetic dissipation.Conventional methods,however,constrain their delicate constructions.Herein,an innovative alternative is proposed:carrageenan-assistant cations-regulated(CACR)strategy,which induces a series of sulfides nanoparticles rooted in situ on the surface of carbon matrix.This unique configuration originates from strategic vacancy formation energy of sulfides and strong sulfides-carbon support interaction,benefiting the delicate construction of defects-rich heterostructures in M_(x)S_(y)/carbon composites(M-CAs).Impressively,these generated sulfur vacancies are firstly found to strengthen electron accumulation/consumption ability at heterointerfaces and,simultaneously,induct local asymmetry of electronic structure to evoke large dipole moment,ultimately leading to polarization coupling,i.e.,defect-type interfacial polarization.Such“Janus effect”(Janus effect means versatility,as in the Greek two-headed Janus)of interfacial sulfur vacancies is intuitively confirmed by both theoretical and experimental investigations for the first time.Consequently,the sulfur vacancies-rich heterostructured Co/Ni-CAs displays broad absorption bandwidth of 6.76 GHz at only 1.8 mm,compared to sulfur vacancies-free CAs without any dielectric response.Harnessing defects-rich heterostructures,this one-pot CACR strategy may steer the design and development of advanced nanomaterials,boosting functionality across diverse application domains beyond electromagnetic response.

Comparative study on the hydrogen storage performance of as-milled MgRENi rapid quenched alloy catalyzed by metal sulfides

The composites of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)as-quenched alloy and 3 wt.%M(M=CoS,CoS_(2),MoS_(2))catalyst were prepared by high-speed vibration ball mill.The effects of metal sulfides on the hydrogenation and dehydrogenation dynamics of alloys were compared.The results show that the as-milled composites contain a large number of amorphous embedded by a small amount of nanocrystals,and there are many point defects.After ball milling,the crystal grain size in the composites containing CoS is relatively larger,followed by CoS_(2)and MoS_(2)again.After hydrogenation,the amorphous phase is crystallized to form Mg_(2)NiH_(4),YH_(3),Pr_(8)H_(18.96),Sm_(3)H_7,Mg,Co or Mo phases,however,Mg_(2)Ni,YH_(2),PrH_(2)and Ni_(3)Y phases appeared after dehydrogenation.The maximum hydrogenation capacity of the composites containing CoS,CoS_(2)and MoS_(2)are 3.939,4.265 and 4.507 wt.%,respectively.The hydrogenation saturation ratio of composite containing MoS_(2)is higher than that of the composites containing CoS and CoS_(2).The dehydrogenation activation energy of the composites containing CoS,CoS_(2)and MoS_(2)is 107.76,68.43 and 63.28 kJ.mol^(-1).H_(2).On the improvement of hydrogen storage performance of Mg_(20)Pr_(1)Sm_(3)Y_(1)Ni_(10)alloy,the catalytic effect of MoS_(2)sulfide is better than that of CoS_(2)sulfide,and which is better than CoS sulfide.

MOF-derived Zn-Co-Ni sulfides with hollow nanosword arrays for high-efficiency overall water and urea electrolysis

Water electrolysis is a promising technology to produce hydrogen but it was severely restricted by the slow oxygen evolution reaction(OER).Herein,we firstly reported an advanced electrocatalyst of MOF-derived hollow Zn-Co-Ni sulfides(ZnS@Co_(9)S_(8)@Ni_(3)S_(2)-1/2,abbreviated as ZCNS-1/2)nanosword arrays(NSAs)with remarkable hydrogen evolution reaction(HER),OER and corresponding water electrolysis performance.To reach a current density of 10 mA cm^(-2),the cell voltage of assembled ZCNS-1/2//ZCNS-1/2 for urea electrolysis(1.314 V)is 208 mV lower than that for water electrolysis(1.522 V)and stably catalyzed for over 15 h,substantially outperforming the most reported water and urea electrolysis electrocatalysts.Density functional theory calculations and experimental result clearly reveal that the properties of large electrochemical active surface area(ECSA)caused by hollow NSAs and fast charge transfer resulted from the Co_(9)S_(8)@Ni_(3)S_(2) heterostructure endow the ZCNS-1/2 electrode with an enhanced electrocatalytic performance.

Synthesis of rare earth sulfides and their UV-vis absorption spectra

Rare earth sulfides were systematically synthesized via the sulfurization of their commercial oxide powders using CS2 gas to shorten sulfurization time, and their UV-vis absorption spectra were investigated. The appropriate sulfurization conditions were studied. For the rare earth sulfides with the same crystal structure, the sulfurization temperature showed increasing tendency with the decrease of rare earth element atomic radii. The UV-vis absorption spectra of rare earth sulfides did not depend on the crystal structure of rare earth sulfides, but on the 4f electronic structure of rare earth element. The data showed that the optical band gaps of rare earth sulfides were irregular, and the values ranged from 1.65 to 3.75 eV.

Petrophysical characteristics of rocks and sulfides from the SWIR hydrothermal field

Study of petrophysical properties of rocks in seafioor hydrothermal fields has great significance for inves- tigation of seafloor hydrothermal activities, especially for polymetallic sulfides prospecting. In the present study, based on the current experimental conditions, we conducted systematic experiments to measure the magnetic susceptibility, electrical resistivity, porosity, density, as well as acoustic wave velocity of seafloor rocks and sulfides. Subsequently, we measured the physical characteristics of hydrothermal sulfides, basalts and peridotites which were collected from newly discovered seafloor hydrothermal fields at 49.6°E, 50.5°E, 5 1°E, 63.5°E, and 63.9°E of the Southwest Indian Ridge （SWIR）. Previously available and newly collected data were combined to characterize the physical differences between polymetallic sulfides and rocks. We also discussed the impact of hydrothermal alteration on the bedrock and demonstrated how these petrophysical properties of rocks can help in geophysical prospecting of seafloor hydrothermal fields as indicators.

The application of nanostructured transition metal sulfides as anodes for lithium ion batteries

With wide application of electric vehicles and large-scale in energy storage systems, the requirement ofsecondary batteries with higher power density and better safety gets urgent. Owing to the merits of hightheoretical capacity, relatively low cost and suitable discharge voltage, much attention has been paid tothe transition metal sulfides. Recently, a large amount of research papers have reported about the appli-cation of transition metal sulfides in lithium ion batteries. However, the practical application of transitionmetal sulfides is still impeded by their fast capacity fading and poor rate performance. More well-focusedresearches should be operated towards the commercialization of transition metal sulfides in lithium ionbatteries. In this review, recent development of using transition metal sulfides such as copper sulfides,molybdenum sulfides, cobalt sulfides, and iron sulfides as electrode materials for lithium ion batteriesis presented. In addition, the electrochemical reaction mechanisms and synthetic strategy of transitionmetal sulfides are briefly summarized. The critical issues, challenges, and perspectives providing a fur-ther understanding of the associated electrochemical processes are also discussed.

Chemical compositions of sulfides in the porphyry Cu ores,Yangla Cu deposit,Yunnan,China:implication for ore genesis

The Yangla Cu deposit is the largest ore deposit in the Jinshajiang polymetallic metallogenic belt,northwest Yunnan,China.There is no consensus on the genesis of the ore deposit owing to the limited studies on the chemical compositions of sulfides.This study used an electron probe micro-analyzer to constrain the chemical compositions of pyrite,chalcopyrite,molybdenite,and sphalerite in the porphyry Cu ore of the Yangla Cu deposit and compared them with the chemical compositions of sulfides in the skarn Cu ore.The trace element contents and their occurrences were used to estimate the metallogenic temperature and infer the genesis of the Yangla deposit.The results show that the sulfides in the porphyry Cu ores have variations of ore element concentrations relative to their theoretical values.Pyrite is depleted in S but elevated in Fe;chalcopyrite is depleted in Cu,Fe,and S;and molybdenite and sphalerite are enriched in S whilst depleted in Mo and Zn.The concentrations of the main metallogenic elements Cu,Fe,Mo,Zn,and S in the porphyry are generally lower than those in skarn,suggesting that the porphyry ore was formed in a moderate to moderate-high temperature metallogenic environment.The formation time may also be slightly later than that of the skarn Cu ore.Elements such as As,Co,Cu.Pb,Zn,Mo,Cd,and Ni mainly exist as isomorphic replacements and mineral inclusions in the sulfides of both porphyry and skarn Cu ores.The trace element features of sulfides in the two ore bodies show that the Yangla Cu deposit may be a composite super imposed ore deposit,and让s formation has undergone the process of exhalative-sedimentary to skarnporphyry mineralization.

Synthesis of 3D Hexagram-Like Cobalt–Manganese Sulfides Nanosheets Grown on Nickel Foam: A Bifunctional Electrocatalyst for Overall Water Splitting

The exploration of low-cost and efficient bifunctional electrocatalysts for oxygen evolution reaction and hydrogen evolution reaction through tuning the chemical composition is strongly required for sustainable resources. Herein, we developed a bimetallic cobalt–manganese sulfide supported on Ni foam(CMS/Ni) via a solvothermal method. It has discovered that after combining with the pure Co_9S_8 and Mn S, the morphologies of CMS/Ni have modulated. The obtained three-dimensionally hexagram-like CMS/Ni nanosheets have a significant increase in electrochemical active surface area and charge transport ability. More than that, the synergetic effect of Co and Mn has also presented in this composite. Benefiting from these, the CMS/Ni electrode shows great performance toward hydrogen evolution reaction and oxygen evolution reaction in basic medium, comparing favorably to that ofthe pure Co_9S_8/Ni and Mn S/Ni. More importantly, this versatile CMS/Ni can catalyze the water splitting in a twoelectrode system at a potential of 1.47 V, and this electrolyzer can be efficiently driven by a 1.50 V commercial dry battery.

Helium, neon and argon isotope compositions of fluid inclu-sions in massive sulfides from the Jade hydrothermal field, the Okinawa Trough

Helium, neon and argon isotope compositions of fluid inclusions have been measured in massive sulfide samples from theJade hydrothermal field in the central Okinawa Trough. Fluid-inclusion 3He/4He ratios are between 6.2 and 10.1 times theair value (Ra), and with a mean of 7.8Ra, which are consistent with the mid-ocean ridge basalt values [3He/4He≈(6Ra^11Ra)]. Values for 20Ne/22Ne are from 10.7 to 11.3, which are significantly higher than the atmospheric ratio (9.8).And the fluid-inclusion 40Ar/36Ar ratios range from 287 to 334, which are close to the atmosperic values (295.5). Theseresults indicate that the noble gases of trapped hydrothermal fluids in massive sulfides are a mixture of mantle- andseawater-derived components, and the helium of fluid inclusions is mainly from mantle, the nelium and argon isotopecompositions are mainly from seawater.

Bifunctional oxygen electrode cobalt–nickel sulfides catalysts originated from intercalated LDH precursors

Bimetallic cobalt-nickel sulfide nanoparticles anchored on S-,N-codoped holey carbon nanosheets(CoNiS-T@NCFs)with a hydrangea-like morphology,were synthesized via a confinement synthesis route,in which an intercalated LDH precursor was subjected to the interlayer-confined carbonization and host-layer sulfurization.The phase transformation and structure evolution(e.g.,atom site occupancy,crystallite size,and cell volume)of the CoNi-S-T@NCFs electrocatalysts,as a function of sulfurization temperatures,were confirmed by X-ray diffraction and Rietveld analyses.The sulfur vacancies effectively enhance the electrocatalytic activity,while the synergistic effect of(Co,Ni)7 S8 alloy and S,N-codoped carbon matrix facilitates the electron transfer and accelerates reaction kinetics,making CoNi-S-900@NCFs an efficient and stable bifunctional electrocatalyst for oxygen reduction reaction(ORR).The rich highvalence Co(Ⅲ)and Ni(Ⅲ)of CoNi-S-900@NCFs facilitates the in-situ transformation of the metal(oxy)hydroxides intermediates with high catalytic activity for oxygen evolution reaction(OER).Thus,with a bifunctional parameter,ΔE,of 0.75 V(E_(j=10,OER)-E_(1/2,ORR)),this electrocatalyst slightly outperforms the state-of-the-art commercial Pt/C+RuO_(2)/C catalyst(ΔE=0.76 V)in alkaline medium.This work demonstrates the influence that the sulfurization temperature has on the relationship between the structure and electrocatalytic performance of bimetallic sulfides prepared by the synthesis strategy using the intercalated LDH precursor.This strategy can be extended to prepare other chalcogenides with binary or ternary transition metals.

Influence of sulfides on the tribological properties of composites produced by pulse electric current sintering

Self-lubricating A1203-15wt% ZrO2 composites with sulfides, such as molybdenum disulfide （MoS2） and tungsten disulfide （WSz） serving as solid lubricants, were fabricated by using the pulse electric current sintering （PECS） technique. The coefficient of friction （COF） of the A1203-15wt% ZrO2 composite without/with sulfides was in the range of 0.37-0.48 and 0.27-0.49, respectively. As the amoant of sul- fides increased, the COF and the wear rate decreased. The reduction in COF and wear rate of the sulfide-containing composite is caused by a reduction in shear stresses between the specimen and the tribological medium due to the formation of a lubricating film resulting from the lamellar structure of sulfides located on the worn surface.

Surface-treatment of Alkaline Earth Sulfides Based Phosphor

A series of alkaline earth sulfides based phosphors Ca_ 0.8 Sr_ 0.2 S∶Eu 2+ ,Tm 3+ were covered with a layer of protective coating with alkaline earth fluorides by heating the mixture of phosphor and NH_4HF_2 at elevated temperatures. The coatings were characterized by means of XRD and SEM. The optical properties of the coated phosphors and the influences of the coating on their properties have been discussed extensively. The stabilities of the coated and uncoated phosphors have been compared.

Fe(NO_3)_3·9H_2O/Fe(HSO_4)_3:An efficient reagent system for the oxidation of alcohols,thiols and sulfides in the absence of solvent

Fe（NO3）3-9H2O/Fe（HSO4）3 was used as an efficient reagent system for the oxidation of alcohols to their corresponding carbonyl compounds. All reactions were performed in the absence of solvent in good to high yields. Under the same reaction conditions, thiols and sulfides were also converted to their corresponding disulfides and sulfoxides, respectively. 2007 Farhad Shirini. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Leaching kinetics of antimony-bearing complex sulfides ore in hydrochloric acid solution with ozone

The leaching kinetics of Sb and Fe from antimony-bearing complex sulfides ore was investigated in HCl solution by oxidation?leaching with ozone.The effects of temperature,HCl concentration,stirring speed and particle size on the process were explored.It is found that the recoveries of Sb and Fe reach86.1%and28.8%,respectively,when the reaction conditions are4.0mol/L HCl,900r/min stirring speed at85°C with<0.074mm particle size after50min leaching.XRD analysis indicates that no new solid product forms in the leaching residue and the leaching process can be described by shrinking core model.The leaching of Sb corresponds to diffusion-controlled model at low temperature(15?45°C)and mixed-controlled model at high temperature(45?85°C),and the apparent activation energies are6.91and17.93kJ/mol,respectively.The leaching of Fe corresponds to diffusion-controlled model,and the apparent activation energy is1.99kJ/mol.Three semi-empirical rate equations are obtained to describe the leaching process.

Interfacial engineering of transition-metal sulfides heterostructures with built-in electric-field effects for enhanced oxygen evolution reaction

Developing highly efficient,durable,and non-noble electrocatalysts for the sluggish anodic oxygen evolution reaction(OER)is the pivotal for meeting the practical demand in water splitting.However,the current transition-metal electrocatalysts still suffer from low activity and durability on account of poor interfacial reaction kinetics.In this work,a facile solid-state synthesis strategy is developed to construct transition-metal sulfides heterostructures(denoted as MS_(2)/NiS_(2),M=Mo or W)for boosting OER electrocatalysis.As a result,MoS2/NiS2 and WS2/NiS2 show lower overpotentials of 300 mV and 320 mV to achieve the current density of 10 mA·cm^(-2),and smaller Tafel slopes of 60 mV.dec^(-1) and 83 mV.dec^(-1)in 1 mol·L^(-1) KOH,respectively,in comparison with the single MoS2,WS2,NiS2,as well as even the benchmark RuO2.The experiments reveal that the designed heterostructures have strong electronic interactions and spontaneously develop a built-in electric field at the heterointerface with uneven charge distribution based on the difference of band structures,which promote interfacial charge transfer,improve absorptivity of OH-,and modulate the energy level more comparable to the OER.Thus,the designed transition-metal sulfides heterostructures exhibit a remarkably high electrocatalytic activity for OER.This study provides a simple strategy to manipulate the heterostructure interface via an energy level engineering method for OER and can be extended to fabricate other heterostructures for various energy-related applications.

Mineralogical characteristics of polymetallic sulfides from the Deyin-1 hydrothermal field near 15°S, southern Mid-Atlantic Ridge

A seafloor hydrothermal field, named Deyin-1 later, near 15°S southern Mid-Atlantic Ridge（SMAR） was newly found during the 22 nd cruise carried out by the China Ocean Mineral Resources Research ＆ Development Association（COMRA）. Sulfide samples were collected at three stations from the hydrothermal field during the26 th cruise in 2012. In this paper, mineralogical characteristics of the sulfides were analyzed with optical microscope, X-ray diffractometer, scanning electron microscope and electron microprobe to study the crystallization sequence of minerals and the process of hydrothermal mineralization. According to the difference of the ore-forming metal elements, the sulfide samples can be divided into three types：（1） the Ferich sulfide, which contains mainly pyrite and chalcopyrite;（2） the Fe-Cu-rich sulfide consisting predominantly of pyrite, chalcopyrite and isocubanite, with lesser amount of sphalerite, marmatite and pyrrhotine; and（3） the Fe-Zn-rich sulfide dominated by pyrite, sphalerite and marmatite, with variable amounts of chalcopyrite, isocubanite, pyrrhotine, marcasite, galena and gratonite. Mineral precipitations in these sulfides are in the sequence of chalcopyrite（isocubanite and possible coarse pyrite）, fine pyrite,sphalerite（marmatite）, galena, gratonite and then the minerals out of the dissolution. Two morphologically distinct generations（Py-I and Py-II） of pyrite are identified in each of the samples; inclusions of marmatite tend to exist in the coarse pyrite crystals（Py-I）. Sphalerite in the Fe-Zn-rich sulfide is characterized by a＂chalcopyrite disease＂ phenomenon. Mineral paragenetic relationships and a wide range of chemical compositions suggest that the environment of hydrothermal mineralization was largely changing. By comparison, the Fe-rich sulfide was formed in a relatively stable environment with a high temperature, but the conditions for the formation of the Fe-Cu-rich sulfide were variable. The Fe-Zn-rich sulfide was precipitated during the hydrothermal venting at relatively low temperature.

Controlled moderative sulfidation-fabricated hierarchical heterogeneous nickel sulfides-based electrocatalyst with tripartite Mo doping for efficient oxygen evolution

An electrocatalyst with heterogeneous nanostructure, especially the hierarchical one, generally shows a more competitive activity than that of its single-component counterparts for oxygen evolution reaction(OER), due to the synergistically enhanced kinetics on enriched active sites and reconfigured electronic band structure. Here this work introduces hierarchical heterostructures into a NiMo@NiS/MoS_(2)@Ni_(2)S_(2)/MoO_(x)(NiMoS) composite by one-pot controlled moderative sulfidation. The optimal solvent composition and addition of NaOH enable NiMoS to own loose and porous structures, smaller nanoparticle sizes, optimal phase composition and chemical states of elements, improving the OER activity of NiMoS. To achieve current densities of 50 and 100 mA cm^(-1), small overpotentials of 275 and 306 mV are required respectively, together with a minor Tafel slope of 58 mV dec^(-1), which outperforms most reported sulfide catalysts and IrO_(2). The synergistic effects in the hierarchical heterostructures expose more active sites,adjust the electronic band structure, and enable the fast charge transfer kinetics, which construct an optimized local coordination environment for high OER electrocatalytic activity. Furthermore, the hierarchical heterostructures suppress the distinct lowering of electrical conductivity and collapse of pristine structures resulted from the metal oxidation and synchronous S leaching during OER, yielding competitive catalytic stability.

Syntheses of (3-Benzyl-4-Aroyl-1,2,4-Triazole-5-yl)[5-(3,4,5-Trimethoxylphenyl)-1,3,4-Oxadizole-2-yl] Sulfides

Twelve new (3-benzyl-4-aroyl-1,2,4-triazole-5-yl)[5-(3,4,5-trimethoxyphenyl)-1,3,4- oxadiazole-2-yl]sulfides(2) have been synthesized from the nucleophilic displacements of 3-benzyl-4- trimethoxyphenyl)-1,3,4-oxadiazole(1). Compounds(2) were screened for their antibacterial activity against E.Coli at 0.01%. The results show that some compounds(2) have strong inhibiting effects

QSPR Studies on the Physicochemical Properties of Polychlorinated Diphenyl Sulfides——The Application of Theoretical Descriptors Derived from Electrostatic Potentials on Molecular Surface

Based on the relationship between the quantitative structure and property（QSPR） of organic compounds, the surface electrostatic potential parameters of 29 polychlorinated diphenyl sulfides（PCDPSs） with experimental values were calculated and extracted, and Multiple Linear Regression（MLR） was used to model the linear relationship between the physicochemical properties（octanol/water partition coefficient, high performance liquid chromatography capacity factor） and molecular structure parameters of PCDPSs. The result shows that the main factors that affect the n-octanol/water partition coefficient and high performance liquid chromatography capacity factor are respectively the number of chlorin atoms substituted on the benzene ring（NCl） and the lowest unoccupied molecular orbital energy（ELUMO）. Secondly, there are also molecular surface electrostatic potentials. This indicates that the molecular surface electrostatic potentials can effectively express the quantitative relationship between the physicochemical properties of PCDPSs and their molecule descriptions. The QSPR models established have strong stability and predictive ability. This also has proved the applicability of molecular surface electrostatic potential parameters in QSPR of PCDPSs.

An Imidazole-functionalized Dioxovanadium Complex with the Highly Selective Oxidation of Sulfides

A novel imidazole-functionalized dioxovanadium complex [V2O2（C2O4）（aIM）4] （aIM =1-allylimidazole） was synthesized by the reaction of VO（acac）2 with 1-allylimidazole and fully characterized by single-crystal X-ray diffraction （SCXRD）,powder X-ray diffraction （PXRD）,X-ray photoelectron spectroscopy （XPS）,Fourier transform infrared spectroscopy （FT-IR） and elemental analyses.Interestingly,the oxalate was in-situ generated from the acetylacetone anion of VO（acac）2 and further coordinated with the vanadium cation and finally complex 1 was achieved.The crystal of complex 1 belongs to the monoclinic system,space group P21/n with a =10.7922（9）,b =10.6296（8）,c =13.2936（11） （A）,μ =0.677 mm^-1,Mr =686.48,V =1516.9（2） A^3,Z =2,Dc =1.503 g/cm^3,F（000） =708,R =0.0543,and wR =0.1517 for 2459 observed reflections with Ⅰ 〉 2σ（Ⅰ）.Notably,complex 1 is further used as catalyst in the oxidation of sulfides using H2O2 as the oxidant and exhibits excellent catalytic performance （conv.up to 95.6%,sele.up to 98.9%）.