Recent update on electrochemical CO_(2)reduction catalyzed by metal sulfide materials

Seeking and developing efficient CO_(2)reduction reaction(CO_(2)RR)electrocatalysts is a hot topic in this era of global warming.Among material candidates for sustainable and cost-effective applications,metal sulfides have attracted attention as promising nature-inspired materials due to multiple adsorption sites which are enhanced by the covalent character of sulfur.This article summarizes the current status regarding the utilization and development of metal sulfide materials as CO_(2)RR electrocatalysts.First,the research background and basic principles of electrochemical CO_(2)RR are introduced.Next,an overview of the main obstacles to developing efficient CO_(2)RR electrocatalysts is presented.The section is followed by a summary of the empirical evidence supporting the application of metal sulfides as CO_(2)RR electrocatalysts beside nature-inspired motivation.The summary of synthesis methods of various metal sulfides is also presented.Furthermore,the paper also highlights the recent works on metal sulfide as efficient CO_(2)RR including the undertaking strategy on the activity enhancement,and finally,discusses the challenges and prospect of metal sulfides-based CO_(2)RR electrocatalysts.Despite recent efforts,metal sulfides remain relatively unexplored as materials for CO_(2)RR electrocatalytic applications.Therefore,this review aims to stimulate novel ideas and research for improved catalyst designs and functionality.

Effect of pyrite, elemental sulfur and ferrous ions on EPS production by metal sulfide bioleaching microbes

Extracellular polymeric substances （EPS） produced by acidophilic bioleaching microorganisms play an important role in the production of acid mine drainage and metal sulfide bioleaching. EPS mediate the contact between microbial cells and growth substrates, having a pivotal role in organic film formation and bacterium-substratum interactions. The production and chemical composition of EPS produced by seven bioleaching strains grown with different substrates were studied. Analysis of the EPS extracted from these strains indicated that the EPS consisted of carbohydrates, proteins and galacturonic acid. The contents of EPS, carbohydrates, proteins and galacturonic acid of EPS were largely related to the kind of strain used and culture condition. The results show that EPS productions of microbes grown with pyrite were significantly higher than those of microbes grown with sulfur or FeSO4·7H2O. The highest EPS production of the seven acidiphilic strains was （159.43±3.93） mg/g, which was produced by Leptospirillum ferriphilum CBCBSUCSU208015 when cultivated with pyrite.

Interfacial engineering of graphitic carbon nitride(g-C_3N_4)-based metal sulfide heterojunction photocatalysts for energy conversion: A review

As one of the most appealing and attractive technologies, photocatalysis is widely used as a promising method to circumvent the environmental and energy problems. Due to its chemical stability and unique physicochemical, graphitic carbon nitride (g-C3N4) has become research hotspots in the community. However, g-C3N4 photocatalyst still suffers from many problems, resulting in unsatisfactory photocatalytic activity such as low specific surface area, high charge recombination and insufficient visible light utilization. Since 2009, g-C3N4-based heterostructures have attracted the attention of scientists worldwide for their greatly enhanced photocatalytic performance. Overall, this review summarizes the recent advances of g-C3N4-based nanocomposites modified with transition metal sulfide (TMS), including (1) preparation of pristine g-C3N4,(2) modification strategies of g-C3N4,(3) design principles of TMS-modified g-C3N4 heterostructured photocatalysts, and (4) applications in energy conversion. What is more, the characteristics and transfer mechanisms of each classification of the metal sulfide heterojunction system will be critically reviewed, spanning from the following categories:(1) Type I heterojunction,(2) Type II heterojunction,(3) p-n heterojunction,(4) Schottky junction and (5) Z-scheme heterojunction. Apart from that, the application of g-C3N4-based heterostructured photocatalysts in H2 evolution, CO2 reduction, N2 fixation and pollutant degradation will also be systematically presented. Last but not least, this review will conclude with invigorating perspectives, limitations and prospects for further advancing g-C3N4-based heterostructured photocatalysts toward practical benefits for a sustainable future.

Influence of Metal Sulfides as Anode Catalysts on Performance of H_2S SOFC

Two anode catalysts with Pt, MoS2 and composite metal sulfides (MoS2+NiS), are investigated for electrochemical oxidation of hydrogen sulfide in solid oxide fuel cell (SOFC) at temperatures 750-850℃. The catalysts comprising MoS2 and MoSa+NiS exhibited good electrical conductivity and catalytic activity. MoS2 and composite catalysts were found to be more active than Pt, a widely used catalyst for high temperature H2S/O2 fuel cell at 750-850℃. However, MoS2 itself sublimes above 450℃. In contrast, composite catalysts containing both Mo and transition metal (Ni) are shown to be stable and effective in promoting the oxidation of H2S in SOFC up to 850℃. However, electric contact is poor between the platinum current collecting layer and the composite metal sulfide layer, so that the cell performance becomes worse. This problem is overcome by adding conductive Ag powder into the anode layer (forming MoS2+NiS+Ag anode material) to increase anode electrical conductance instead of applying a thin layer of platinum on the top of anode.

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.

Advanced metal sulfide anode for potassium ion batteries

Potassium-ion batteries（KIBs） are a promising alternative to lithium-ion batteries owning to the abundance of potassium on Earth and the relatively low K/K＋redox couple. To date, KIBs remains its infancy and the investigation of anode materials mainly focused on carbon-based materials, which deliver limited reversible capacity. Hence, it is imperative to explore alternative anode materials with high reversible capacity for KIBs. Recently, a pioneering work from Chen’s group reported a nanocomposite of Sb2S3 nanoparticles anchored on porous S,N-codoped graphene（denoted as Sb2S3-SNG） as an advanced anode material for KIBs, which exhibited remarkable enhancements of both capacity and cycling stability, highlighting the rational structure design of Sb2S3-SNG for maximum utilization of Sb2S3 nanoparticles and graphene layers for energy storage applications in high-performance KIBs.

Electrolyte/Structure‑Dependent Cocktail Mediation Enabling High‑Rate/Low‑Plateau Metal Sulfide Anodes for Sodium Storage

As promising anodes for sodium-ion batteries,metal sulfides ubiquitously suffer from low-rate and high-plateau issues,greatly hindering their application in full-cells.Herein,exemplifying carbon nanotubes(CNTs)-stringed metal sulfides superstructure(CSC)assembled by nano-dispersed SnS_(2) and CoS_(2) phases,cocktail mediation effect similar to that of high-entropy materials is initially studied in ether-based electrolyte to solve the challenges.The high nano-dispersity of metal sulfides in CSC anode underlies the cocktail-like mediation effect,enabling the circumvention of intrinsic drawbacks of different metal sulfides.By utilizing ether-based electrolyte,the reversibility of metal sulfides is greatly improved,sustaining a long-life effectivity of cocktail-like mediation.As such,CSC effectively overcomes low-rate flaw of SnS_(2) and highplateau demerit of CoS_(2),simultaneously realizes a high rate and a low plateau.In half-cells,CSC delivers an ultrahigh-rate capability of 327.6 mAh g^(−1) anode at 20 A g^(−1),far outperforming those of monometallic sulfides(SnS_(2),CoS_(2))and their mixtures.Compared with CoS_(2) phase and SnS_(2)/CoS_(2) mixture,CSC shows remarkably lowered average charge voltage up to ca.0.62 V.As-assembled CSC//Na1.5VPO4.8F0.7 full-cell shows a good rate capability(0.05~1.0 A g^(−1),120.3 mAh g^(−1) electrode at 0.05 A g^(−1))and a high average discharge voltage up to 2.57 V,comparable to full-cells with alloy-type anodes.Kinetics analysis verifies that the cocktail-like mediation effect largely boosts the charge transfer and ionic diffusion in CSC,compared with single phase and mixed phases.Further mechanism study reveals that alternative and complementary electrochemical processes between nano-dispersed SnS_(2) and CoS_(2) phases are responsible for the lowered charge voltage of CSC.This electrolyte/structure-dependent cocktail-like mediation effect effectively enhances the practicability of metal sulfide anodes,which will boost the development of high-rate/-voltage sodium-ion full batteries.

Single-phase bimetal sulfide or metal sulfide heterojunction:Which one is better for reversible oxygen electrocatalyst?

Bimetallic sulfides,integrating the merits of individual components,are ideal structures for efficient electrocatalysis.However,for bimetallic sulfides including metal sulfide heterojunctions(MSH)and singlephase bimetallic sulfides(SBS),it is still unclear about which one has better catalytic activity toward reversible oxygen catalysis and its difference on catalytic mechanism.In this work,we demonstrate a bimetallic sulfide electrocatalyst that could transform from metal sulfide heterojunction(CoS/FeS)to single-phase bimetallic sulfide(CoFeS_(2))through a facile temperature control strategy.The single-phase bimetallic sulfide(CoFeS_(2))affords high intrinsic activity,fast reaction kinetics and superior durability toward oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Density functional theory(DFT)simulations reveal that the(CoFeS_(2))has homogeneous electron distribution of the CoFeS_(2)structure,improves the central energy level of d band,and optimizes the O*and OOH*intermediate and efficiently reduces the energy barrier of the reaction rate-determining step(RDS).The assembled rechargeable zincair battery is more stable than the Pt/C and IrO_(2) assemblies due to the excellent electrocatalytic activity and stability of CoFeS_(2)/NC,suggesting that it has potential for use in practical applications.

Design and modification of metal sulfide-based catalysts for lithiumsulfur batteries

Metal sulfide(MS)have good conductivity,strong adsorption ability,and excellent catalytic activity for the conversion of sulfur species,and thus,show great promise as the catalysts in LieS batteries.However,the relationship between their properties and electrochemical performance is still unclear.Thus,further in-depth discussions are required to improve their design in Li-S batteries.This review systematically summarizes the basic structural and electrochemical properties of MSs and highlights the advantages that guarantee them as high-performance catalysts in Li-S batteries.Then,various modification strategies for MSs to enhance the catalytic activity,efficiency,and stability are also reviewed.At last,future opportunities for MS catalysts in Li-S batteries are proposed.

Designing metal sulfide-based cathodes and separators for suppressing polysulfide shuttling in lithium-sulfur batteries

Lithium-sulfur(Li-S)batteries,known for their high energy density,are attracting extensive research interest as a promising next-generation energy storage technology.However,their widespread use has been hampered by certain issues,including the dissolution and migration of polysulfides,along with sluggish redox kinetics.Metal sulfides present a promising solution to these obstacles regarding their high electrical conductivity,strong chemical adsorption with polysulfides,and remarkable electrocatalytic capabilities for polysulfide conversion.In this review,the recent progress on the utilization of metal sulfide for suppressing polysulfide shuttling in Li-S batteries is systematically summarized,with a special focus on sulfur hosts and functional separators.The critical roles of metal sulfides in realizing high-performing Li-S batteries have been comprehensively discussed by correlating the materials’structure and electrochemical performances.Moreover,the remaining issues/challenges and future perspectives are highlighted.By offering a detailed understanding of the crucial roles of metal sulfides,this review dedicates to contributing valuable knowledge for the pursuit of high-efficiency Li-S batteries based on metal sulfides.

Applications of Rare Earth Promoted Transition Metal Sulfides in Electrocatalysis

With the rapid consumption of fossil fuels and the resulting environmental problems,researchers are working to find sustainable alternative energy and energy storage and conversion methods.Transition metal sulfur compounds have attracted extensive attention due to their excellent electrical conductivity,low cost,adjustable components and good electrocatalytic performance.As an alternative to noble metal catalysts,they have emerged as a promising electrocatalyst.However,their low catalytic activity and poor stability limit their large-scale practical applications.Rare earth elements,known as industrial vitamins,are widely used in various fields due to their special redox properties,oxygen affinity and electronic structure.Therefore,the construction of rare earth promoted transition metal sulfides is of far-reaching significance for the development of catalysts.Here,we review the applications of various rare earth promoted transition metal sulfides in energy storage and conversion in recent years,which focuses on three ways in rare earth promoted transition metal sulfide,including doping,interfacial modification engineering and structural facilitation.As well,these materials are used in electrochemical reactions such as OER,HER,ORR,CO_(2)RR,and so on,in order to explore the important role of rare earth in the field of electrocatalysis,the future challenges and opportunities.

Sulphur vacancy defects engineered metal sulfides for amended photo(electro)catalytic water splitting: A review

Vacancy engineering in metal sulfides has garnered enormous attention from researchers because of their outstanding ability to modulate the optical and physiochemical properties of photocatalysts.Typically,in the case of sulfides,the catalytic activity is drastically hindered by the quick reassembly of excitons and the photocorrosion effect.Hence designing and generating S-vacancies in metal sulfides has emerged as a potential strategy for attaining adequate water splitting to generate H_(2) and O_(2) because of the simulta-neous improvement in the optoelectronic features.However,developing efficient catalysts that manifest optimal photo(electro)catalytic performance for large-scale applicability remains challenging.Therefore,it is of utmost interest to explore the insightful features of creating S-vacancy and study their impact on catalytic performance.This review article aims to comprehensively highlight the roles of S-vacancy in sulfides for amended overall water-splitting activity.The photocatalytic features of S-vacancies modulated metal sulfides are deliberated,followed by various advanced synthetic and characterization techniques for effectual generation and identification of vacancy defects.The specific aspects of S-vacancies in refin-ing the optical absorption range charge carrier dynamics,and photoinduced surface chemical reactions are critically examined for overall water splitting applications.Finally,the vouchsafing outlooks and op-portunities confronting the defect-engineered(S-vacancy)metal sulfides-based photocatalysts have been summarized.

Superhydrophobic Co/Fe sulfide nanoparticles and single-atoms doped carbon nanosheets composite air cathode for high-performance zinc-air batteries

Development of a high-performance bifunctional catalyst is essential for the actual implementation of zinc-air batteries in practical applications.Herein,a bifunctional cathode of Co_(3)S_(4)/FeS heterogeneous nanoparticles embedded in Co/Fe single-atom-loaded nitrogen-doped carbon nanosheets is designed.Cobalt-iron sulfides and single atomic sites with Co-N_(4)/Fe-N_(4)configurations are confirmed to coexist on the carbon matrix by EXAFS spectroscopy.3D self-supported super-hydrophobic multiphase composite cathode provides abundant active sites and facilitates gas–liquid-solid three-phase interface reactions,resulting in excellent electrocatalytic activity and batteries performance,i.e.,an OER overpotential(η_(10))of 260 mV,a half-wave potential(E_(1/2))of 0.872 V for ORR,aΔE of 0.618 V,and a discharge power density of 170 mW cm^(−2),a specific capacity of 816.3 mAh g^(−1).DFT analysis shows multiphase coupling of sulfide heterojunction through single-atomic metal doped carbon nanosheets reduces offset on center of electronic density of states before and after oxygen adsorption,and spin density of adsorbed oxygen with same spin orientation,leading to weakened charge/spin interactions between adsorbed oxygen and substrate,and a lowered oxygen adsorption energy to accelerate OER/ORR.

Recent developments in metal phosphide and sulfide electrocatalysts for oxygen evolution reaction

Oxygen evolution reaction(OER),as an important half‐reaction involved in water splitting,has been intensely studied since the last century.Transition metal phosphide and sulfide‐based compounds have attracted increasing attention as active OER catalysts due to their excellent physical and chemical characters,and massive efforts have been devoted to improving the phosphide and sulfide‐based materials with better activity and stability in recent years.In this review,the recent progress on phosphide and sulfide‐based OER electrocatalysts in terms of chemical properties,synthetic methodologies,catalytic performances evaluation and improvement strategy is reviewed.The most accepted reaction pathways as well as the thermodynamics and electrochemistry of the OER are firstly introduced in brief,followed by a summary of the recent research and optimization strategy of phosphide and sulfide‐based OER electrocatalysts.Finally,some mechanistic studies of the active phase of phosphide and sulfide‐based compounds are discussed to give insight into the nature of active catalytic sites.It is expected to indicate guidance for further improving the performances of phosphide and sulfide‐based OER electrocatalysts.

Metal sulfides based composites as promising efficient microwave absorption materials:A review

The increasingly severe electromagnetic microwave pollution raises higher requirements for the development of efficient microwave absorption(MA)materials.Metal sulfides are regarded as potential robust MA materials because of their unique optical,thermal,electrical,and magnetic properties,as well as the controllable microstructures.However,due to the limited MA performances of unary metal sulfides,morphology regulations and foreign materials hybridizations are adopted as effective strategies to improve their MA performances.Recent years witnessed the fast research progresses on the metal sulfides based MA materials and thus,a systematic literature survey on the materials design,fabrication,characterizations,MA behaviors,and the mechanisms behind is,highly desirable to summarize the rapid progress of this hot research area so as to provide guidance for the future development trend.This review firstly reviewed the research background,research progress,and basic principles of MA materials.Subsequently,the present synthetic methods and performance improvement strategies of metal sulfides based MA materials are systematically introduced.Then,by comparing the MA properties of one-dimensional,two-dimensional,and three-dimensional metal sulfides based composites,the influence of dimensionality and morphology on the MA properties are analyzed.By summarizing the research process of metal sulfides/dielectrics composites,metal sulfides/magnets composites,and metal sulfides/dielectrics/magnets composites MA materials,the influence of foreign materials hybridizations on the loss mechanisms and impedance matching conditions of metal sulfides based composites are revealed.Finally,the challenges and development prospects of metal sulfides based MA materials are presented.This review would provide a comprehensive understanding and insightful guidance for the exploration and development of efficient MA materials with thin thickness,light weight,wide absorption bandwidth,and strong absorption intensity.

Shining light on transition metal sulfides:New choices as highly efficient antibacterial agents

Globally,millions of people die of microbial infection-related diseases every year.The more terrible situation is that due to the overuse of antibiotics,especially in developing countries,people are struggling to fight with the bacteria variation.The emergence of super-bacteria will be an intractable environmental and health hazard in the future unless novel bactericidal weapons are mounted.Consequently,it is critical to develop viable antibacterial approaches to sustain the prosperous development of human society.Recent researches indicate that transition metal sulfides(TMSs)represent prominent bactericidal application potential owing to the meritorious antibacterial performance,acceptable biocompatibility,high solar energy utilization efficiency,and excellent photo-to-thermal conversion characteristics,and thus,a comprehensive review on the recent advances in this area would be beneficial for the future development.In this review article,we start with the antibacterial mechanisms of TMSs to provide a preliminary understanding.Thereafter,the state-of-the-art research progresses on the strategies for TMSs materials engineering so as to promote their antibacterial properties are systematically surveyed and summarized,followed by a summary of the practical application scenarios of TMSs-based antibacterial platforms.Finally,based on the thorough survey and analysis,we emphasize the challenges and future development trends in this area.

Progress and Prospects of Transition Metal Sulfides for Sodium Storage

Sodium-ion battery(SIB),one of most promising battery technologies,offers an alternative low-cost solution for scalable energy storage.Developing advanced electrode materials with superior electrochemical performance is of great significance for SIBs.Transition metal sulfides that emerge as promising anode materials have advantageous features particularly for electrochemical redox reaction,including high theoretical capacity,good cycling stability,easily-controlled structure and modifiable chemical composition.In this review,recent progress of transition metal sulfides based materials for SIBs is summarized by discussing the materials properties,advanced design strategies,electrochemical reaction mechanism and their applications in sodium-ion full batteries.Moreover,we propose several promising strategies to overcome the challenges of transition metal sulfides for SIBs,paving the way to explore and construct advanced electrode materials for SIBs and other energy storage devices.

A generalized one-step in situ formation of metal sulfide/reduced graphene oxide nanosheets toward high-performance supercapacitors

Metal sulfides are promising candidates for supercapacitors,but their slow reaction kinetics hinders their electrochemical performance.Large electrochemical surface area and combination with conductive carbon are potential methods to improve their capacitive performance.However,seeking for a generalized and simple approach to prepare two-dimensional composites of metal sulfide and conductive carbon for supercapacitors is challengeable.Herein,a generalized and facile one-step pyrolysis method was designed for in situ growth of cobalt nickel sulfides(CoNi2S4)on reduced graphene oxide(rGO)nanosheets(CoNi2S4/rGO)under mild conditions.The as-prepared CoNi2S4/rGO materials possess the nanoparticles-on-nanosheets structure,which is effective to provide a myriad of active sites and optimized electron/ion diffusion pathway.Benefiting from those advantages,the resultant CoNi2S4/rGO electrodes exhibit impressed specific capacitances of 1526 and 988 F g^−1 at 2 and 20 A g^−1,respectively.The supercapacitors based on CoNi2S4/rGO showcase an operation potential window of 1.6 V,and energy density of 54.8 W h kg^−1 at the power density of 798 W kg^−1.The capacitance retention of the supercapacitor is about 93.7%after 8000 cycles at 3 A g^−1.Moreover,a series of metal sulfide/rGO hybrids are obtained by this generalized strategy,which could be extended to construct electrode materials for various energy devices.

Magnetic separation of metal sulfides/oxides by Fe3O4 at room temperature and atmospheric pressure

The recovery of heterogeneous catalysts can save costs and avoid secondary pollution,but its separation efficiency and recovery cost are limited by conventional separation methods such as precipitation–flocculation,centrifugation and filtration.In this paper,we found that surface-defective metal sulfides/oxides(WS2,CuS,ZnS,MoS2,CdS,TiO2,MoO2 and ZnO)commonly used in advanced oxidation processes(AOPs)could be magnetically recovered at room temperature and atmospheric pressure by mechanically mixing with Fe3O4.Zeta potential,Raman,X-ray photoelectron spectroscopy(XPS)and electro-spin resonance(ESR)spectra were measured to explore the mechanism of the magnetic separation phenomenon.The exposed active metal sites on the surface of defective metal sulfides/oxides are beneficial for the formation of chemical bonds,which are combined with electrostatic force to be responsible for the magnetic separation.Moreover,other factors affecting the magnetic separation were also investigated,such as the addition of amount of Fe3O4,different solvents and particle sizes.Finally,WS2 was chosen to be applied as a co-catalyst in Fenton reaction,which could be well separated by the magnetic Fe3O4 to achieve the recycle of catalyst in Fenton reaction.Our research provides a general strategy for the recycle of metal sulfides/oxides in the catalytic applications.

Tailoring the spin state of active sites in amorphous transition metal sulfides topromoteoxygen electrocatalysis

Spin regulation of active sites is sparking much interest in boosting oxygen electrocatalytic performance.However,in amorphous electrocatalysts,the design principle of spin regulation to promote catalytic activity remains unclear.Herein,we synthesized a series of heteroatom-doped amorphous transition metal sulfides with regulated spin states using a one-step hydrothermal process.Especially in Modoped CoS,the spin state of Co^(2+)was successfully modulated to the low-spin state,which could optimize the adsorption free energy of various intermediates,improving the oxygen reduction reaction kinetics.The fabricated Zn-air batteries(ZABs)delivered good cycle stability(over 100 h).The large ZAB(100 cm^(2))exhibited a high discharge voltage(1.25 V under 0.5 A)and a superior overall mass-energy density(93 W h kg^(−1)),which illuminated a 2.5-m light-emitting-diode ribbon for over seven days.This work provides new insight into the mechanism of engineering spin states in amorphous materials for oxygen electrocatalysis.