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The electrochemical output of lithium‐sulfur batteries is highly restricted by the dissolution and shuttling of polysulfide intermediates, which leads to the polysulfide shuttle effect. The binary metal sulfides offer a greater number of active sites and better polysulfide interaction compared to the unitary metal sulfides. Herein, a nickel cobalt sulfide‐carbon nanotube nanocomposite is devised as a highly efficient separator coater for high‐energy Li‐S batteries. The nanocomposite is featured with superior polysulfide confinement ability due to its dual metal sites and improved ionic and electronic conductivity. The material also possesses enhanced electrolyte wettability, better interfacial properties, and frequent electrolyte uptake. By virtue of the above‐mentioned superiorities, the cell reveals an initial discharge capacity of 1152 mAh g−1 at 0.5 C rate and maintains a retained capacity of 82% after 500 cycles. The cell also shows significant electrochemical results with a magnificent rate delivery of 714 mAh g−1 at 2 C rate and maintains a constant open‐circuit potential for 100 h. [ABSTRACT FROM AUTHOR]

Nanomaterials have found use in a number of relevant energy applications. In particular, nanoscale motifs of binary metal sulfides can function as conversion materials, similar to that of analogous metal oxides, nitrides, or phosphides, and are characterized by their high theoretical capacity and correspondingly low cost. This review focuses on structure–composition–property relationships of specific relevance to battery applications, emanating from systematic attempts to either (1) vary and alter the dimension of nanoscale architectures or (2) introduce conductive carbon-based entities, such as carbon nanotubes and graphene-derived species. In this study, we will primarily concern ourselves with probing metal sulfide nanostructures generated by a microwave-mediated synthetic approach, which we have explored extensively in recent years. This particular fabrication protocol represents a relatively facile, flexible, and effective means with which to simultaneously control both chemical composition and physical morphology within these systems to tailor them for energy storage applications. [ABSTRACT FROM AUTHOR]

Mercury pollution from coal-fired power plants has always been an environmental concern, and adsorption technology is an effective method for Hg0 removal. In this study, copper-iron binary metal sulfide modified activated carbon ( CuFeS x / AC ) adsorbent was synthesized. The performance and mechanism of mercury removal were tested by adsorption experiments and characterization methods. The results showed that the mercury removal efficiency of Cu 2 Fe 1 S x / AC under simulated flue gas (SFG) conditions at 150 °C could reach 91%, which was higher than CuS x / AC and FeS x / AC . Compared with CuS x / AC , the introduction of Fe increased the proportion of Cu + , which was usually linked to S - , resulting in the generation of more CuS (CuISI) species. Meanwhile, the generation of active sulfur sites such as FeS 2 was generated, which had a facilitative effect on the oxidation of Hg0. Stable HgS was the predominant product on the adsorbent surface. The 2% sulfur loadings had significantly improved the sulfur resistance of conventional AC. [ABSTRACT FROM AUTHOR]

Abstract In recent years, the development of lithium-ion batteries (LIBs) with high energy density has become one of the important research directions to fulfill the needs of electric vehicles and smart grid technologies. Nowadays, traditional LIBs have reached their limits in terms of capacity, cycle life, and stability, necessitating their further improvement and development of alternative materials with remarkably enhanced properties. A nitrogen-containing carbon nanotube (N-CNT) host for bimetallic sulfide (NiCo2S4) is proposed in this study as an anode with attractive electrochemical performance for LIBs. The prepared NiCo2S4/N-CNT nanocomposite exhibited improved cycling stability, rate performance, and an excellent reversible capacity of 623.0 mAh g–1 after 100 cycles at 0.1 A g–1 and maintained a high capacity and cycling stability at 0.5 A g–1. The excellent electrochemical performance of the composite can be attributed to the unique porous structure, which can effectively enhance the diffusivity of Li ions while mitigating the volume expansion during the charge–discharge processes.

Nanomaterials have found use in a number of relevant energy applications. In particular, nanoscale motifs of binary metal sulfides can function as conversion materials, similar to that of analogous metal oxides, nitrides, or phosphides, and are characterized by their high theoretical capacity and correspondingly low cost. This review focuses on structure–composition–property relationships of specific relevance to battery applications, emanating from systematic attempts to either (1) vary and alter the dimension of nanoscale architectures or (2) introduce conductive carbon-based entities, such as carbon nanotubes and graphene-derived species. In this study, we will primarily concern ourselves with probing metal sulfide nanostructures generated by a microwave-mediated synthetic approach, which we have explored extensively in recent years. This particular fabrication protocol represents a relatively facile, flexible, and effective means with which to simultaneously control both chemical composition and physical morphology within these systems to tailor them for energy storage applications.

In recent years, the development of lithium-ion batteries (LIBs) with high energy density has become one of the important research directions to fulfill the needs of electric vehicles and smart grid technologies. Nowadays, traditional LIBs have reached their limits in terms of capacity, cycle life, and stability, necessitating their further improvement and development of alternative materials with remarkably enhanced properties. A nitrogen-containing carbon nanotube (N-CNT) host for bimetallic sulfide (NiCo2S4) is proposed in this study as an anode with attractive electrochemical performance for LIBs. The prepared NiCo2S4/N-CNT nanocomposite exhibited improved cycling stability, rate performance, and an excellent reversible capacity of 623.0 mAh g–1 after 100 cycles at 0.1 A g–1 and maintained a high capacity and cycling stability at 0.5 A g–1. The excellent electrochemical performance of the composite can be attributed to the unique porous structure, which can effectively enhance the diffusivity of Li ions while mitigating the volume expansion during the charge–discharge processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synthesis and structure tailoring of binary metal sulphide light-responsive photocatalyst. • Structural and morphological characteristics were scrutinized using advanced techniques. • Solar light assested efficient photocatalytic degradation of Erichrome Black T (EBT) dye. • The quadratic model was the best-fitted model of response surface methodology. Among different types of organic wastes originating from the industrial sector, dyes constitute a major part due to their massive deployment and subsequent elimination. Erichrome Black T (EBT) dye is one of those days, which is incredibly detrimental to sentient (living) creatures due to its significant adverse health properties. Herein, we have focused on the photocatalytic degradation as an efficient process for EBT degradation by employing clean, renewable sources of energy (sunlight irradiations). In this regard, a novel photocatalyst was designed using binary metal sulfide nanoparticles. The solvothermal technique was used to effectively produce iron zinc sulfide nanoparticles (Fe 2 Zn 3 S 5 -NPs). The morphology of the obtained photocatalyst was confirmed by SEM findings, the Fe 2 Zn 3 S 5 -NPs were in the solid powdered form and had a shiny appearance. The average particle size was found to be 61.4 nm. Iron and zinc had noticeable peaks in the EDX spectrum, which corroborated the assertion that the nanoparticles had been fabricated. FTIR spectrum displayed the synthesis of Fe 2 Zn 3 S 5 -NPs functional groups. XRD analysis verified the hexagonal and crystalline structure of zinc and iron nanoparticles with an average crystallite size of 17.84 nm. The bandgap of Fe 2 Zn 3 S 5 -NPs was 1.9 eV using Tauc's plot and Tauc's equation. The Fe 2 Zn 3 S 5 -NPs exhibited a superior photocatalytic degradation rate of up to 98.01% for 50 ppm EBT concentration at a catalyst dosage of 0.1 g, pH 3, and for 1 h of solar light irradiation contact. EBT dye photodegraded in the presence of Fe 2 Zn 3 S 5 -NPs following the pseudo-first-order kinetics, and the Fe 2 Zn 3 S 5 -NPs efficiently degraded EBT dye over the course of four cycles, without a noticeable loss in its efficiency. The current study intends to design a novel binary metal sulfide nanoparticles for the efficient and complete removal of dyes from industrial effluents. [ABSTRACT FROM AUTHOR]

In this work, we report a sensitive and selective electrochemical sensor for the detection of dopamine (DA) neurotransmitter based on VS 2 -SnS 2 /f-MWCNT hybrids. Herein, the binary metal sulfide (VS 2 -SnS 2) was synthesized via single step hydrothermal route and hybrids with f-MWCNT via the ultrasonication process. The as-prepared VS 2 -SnS 2 /f-MWCNT hybrids were characterized through the FESEM, EDX and elemental mapping, TEM, XPS, Raman and XRD techniques. The electrochemical performance and catalytic activity of the modified electrodes were probed using electrochemical impedance spectra (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Interestingly, DPV results exhibits an appreciable linear range from 0.025 to 1017 μM and LOD of 0.008 μM. The selectivity study was performed to prove the high selectivity of the VS 2 -SnS 2 /f-MWCNT hybrids modified electrode. Furthermore, the practical applicability of the DA sensor was scrutinized in human serum sample and rat brain sample. Image 1 • Heterostructured VS 2 -SnS 2 bimetal sulfides synthesized via the single step hydrothermal method. • High conductive functionalized multiwalled carbon nanotubes hybrids with VS 2 -SnS 2 through the ultrasonication technique. • Electrochemical performance of the modified electrode was evaluated by CV and DPV techniques. • Selectivity of the DA sensor was demonstrated clearly with co-existing interfering substances. • Practical application of the sensor was demonstrated in rat brain and human serum samples. [ABSTRACT FROM AUTHOR]

Porous core–shell CuCo2S4 nanospheres that exhibit a large specific surface area, sufficient inner space, and a nanoporous shell were synthesized through a facile solvothermal method. The diameter of the core–shell CuCo2S4 nanospheres is approximately 800 nm„ the radius of the core is about 265 nm and the thickness of the shell are approximately 45 nm, respectively. On the basis of the experimental results, the formation mechanism of the core–shell structure is also discussed. These CuCo2S4 nanospheres show excellent Li storage performance when used as anode material for lithium‐ion batteries. This material delivers high reversible capacity of 773.7 mA h g−1 after 1000 cycles at a current density of 1 A g−1 and displays a stable capacity of 358.4 mA h g−1 after 1000 cycles even at a higher current density of 10 A g−1. The excellent Li storage performance, in terms of high reversible capacity, cycling performance, and rate capability, can be attributed to the synergistic effects of both the core and shell during Li+ ion insertion/extraction processes. It's the small things: Porous core–shell CuCo2S4 nanospheres were synthesized through a facile solvothermal method. This developed synthetic approach could be extended to fabricate other core–shell mixed‐transition‐metal sulfides that could be applied to renewable energy storage. These core–shell CuCo2S4 nanospheres exhibit excellent electrochemical performances as an anode material for LIBs at high current density (see figure). [ABSTRACT FROM AUTHOR]

Developing electrode materials with high specific capacitance within both positive and negative potential window is an effective way to obtain aqueous supercapacitors with high energy density. In this work, P doped Fe-Co-S binary metal sulfides (Fe-Co-S/P) was demonstrated to show high specific capacitance within a wide potential window from − 1–0.55 V. When used as cathode, it exhibited a specific capacitance of 0.8 F cm−2 (320 F g−1). After 20,000 cycles at 20 mA cm−2, it even increased to 242.3% of the initial capacitance. When used as anode, it also had a specific capacitance of 1.34 F cm−2 (536 F g−1) and satisfied cyclic performance (71.4% of the initial capacitance after 20,000 cycles). Moreover, the symmetric supercapacitors (SSCs) assembled with the Fe-Co-S/P electrodes delivered high energy density of 106.42 Wh kg−1 at a power density of 800 W kg−1 and exhibited excellent cyclic stability by preserving 93.9% of the initial capacitance after 5000 cycles. This work not only establishes Fe-Co-S/P as a high-performance supercapacitor electrode material, but also provides a new strategy to design and construct high-performance aqueous SSCs. [Display omitted] • High-performance Fe-Co-S/P in a wide potential window is designed and prepared. • Unique nanostructure and enhanced conductivity are obtained with proper NH 4 F dosage. • Fe-Co-S/P based SSC exhibits high energy density at a high working voltage of 1.06 V. [ABSTRACT FROM AUTHOR]

SnS has been extensively studied as an anode material for sodium storage owing to its high capacity and unique layer spacing. However, the rapid capacity decay and sluggish reaction kinetics result in SnS exhibiting poor electrochemical performance, which prevents its practical application. Herein, the hollow SnS/ZnS nanoboxes (ZSS@NC) with rich phase boundaries have been constructed and utilized as the anode material of SIBs. The in-situ XRD analysis clearly illustrates the structural transformation of the electrode material during sodium storage and the regeneration of the heterointerface. Furthermore, kinetic analysis combined with ex-situ tests show that the excellent properties of heterostructure composites are inextricably linked to the synergistic effect of heterojunction surfaces. As expected, the ZSS@NC heterostructure provides a reversible capacity of 553.5 mA h g−1 at 0.2 A g−1 and good rate capability with an average capacity of 62.3% at 5 A g−1 compared to 0.1 A g−1. The elevated Na-storage properties indicate that the heterointerface engineering strategy has a broad promise for improving the application of electrode materials. • Successful construction of SnS/ZnS@NC composites by introducing heterointerface engineering. • Phase boundaries are favorable to accelerate the kinetic behavior of sodium storage. • Through in-situ XRD, the reaction mechanism and interphase evolution of SnS/ZnS@NC composite are revealed. • The ex-situ EIS are used to analyse impedance changes in the reaction. [ABSTRACT FROM AUTHOR]

Mercury pollution from coal-fired power plants has always been an environmental concern, and adsorption technology is an effective method for Hg 0 removal. In this study, copper-iron binary metal sulfide modified activated carbon ([Formula: see text]) adsorbent was synthesized. The performance and mechanism of mercury removal were tested by adsorption experiments and characterization methods. The results showed that the mercury removal efficiency of [Formula: see text] under simulated flue gas (SFG) conditions at 150 °C could reach 91%, which was higher than [Formula: see text] and [Formula: see text]. Compared with [Formula: see text], the introduction of Fe increased the proportion of [Formula: see text], which was usually linked to [Formula: see text], resulting in the generation of more [Formula: see text](Cu I S I ) species. Meanwhile, the generation of active sulfur sites such as [Formula: see text] was generated, which had a facilitative effect on the oxidation of Hg 0 . Stable [Formula: see text] was the predominant product on the adsorbent surface. The 2% sulfur loadings had significantly improved the sulfur resistance of conventional AC., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

H 2 evolution performance (a) and hydrogen production rate (b) of different samples. The H 2 evolution performance of pure CdS is very poor, while ZnS, CdS/ZnS hybrid and ZnCdS solid solution reveal superior hydrogen evolution performance than pure CdS. At same reaction time, pure ZnS shows better hydrogen evolution ability than CdS/ZnS hybrids (638.5 μmol·g−1·h−1), which the average H 2 evolution efficiency of ZnS is 1437.8 μmol·g−1·h−1. Notably, it can be seen that the hydrogen evolution content of ZnCdS is best than that of pure ZnS, and the H 2 production rate of ZnCdS reaches 2031.8 μmol·g−1·h−1. According to calculation, the hydrogen evolution efficiency of ZnCdS is as about 3.18 and 1.41 times as that of CdS/ZnS and ZnS, respectively. [Display omitted] • Zn, Cd bimetallic sulfide solid solution were fabricated by microwave irradiation. • ZnCdS solid solution possesses superior photocatalytic H 2 evolution property. • The photocatalytic H 2 evolution efficiency reaches 2031.8 μmol·g−1·h−1. Zn, Cd bimetallic sulfide (ZnCdS) with fine nanoparticles was prepared with microwave synthesis, and its morphology and structure were analyzed by electron microscope and X-ray diffractometer (XRD). Moreover, the effect of microwave power and microwave time on the photocatalytic H 2 evolution property of ZnCdS was explored. Research results show that the ZnCdS solid solution was obtained by the microwave synthesis method, which shows a good photocatalytic hydrogen evolution property. When the microwave power is 320 W and the microwave time is 20 min, the as-prepared ZnCdS solid solution products have the best photocatalytic H 2 evolution performance, which its value reaches 2031 μmol/g h. [ABSTRACT FROM AUTHOR]

• Novel Ni 3 Sn 2 S 2 nanoflowers were prepared by one-pot hydrothermal and ion corrosion. • The optimized Ni 3 Sn 2 S 2 displays rational 3D flower-like composite structure. • Ni 3 Sn 2 S 2 /Ni foam is firstly used as an electrode material for supercapacitor. • The fabricated asymmetric device shows ultrahigh energy density of ∼ 5.22 mWh cm−3. Binary system sulfides hold tremendous potential for the manufacture of high-performance supercapacitors because of their rich transition states. Herein, three-dimensional Ni 3 Sn 2 S 2 flower-like materials on Ni foam are ingeniously created via a simple one-pot hydrothermal and ion corrosion for employing as the electrode material in supercapacitors for the first time. According to the morphology in different reaction time, the growth mechanism of the flower-like Ni 3 Sn 2 S 2 is further proposed. The morphology of as-prepared optimal sample indicates that the space of material is fully utilized to form a favorable compound structure with interconnected and uniformly branched nanosheets on the surface of polyhedrons. Electrochemical measurement reveals that Ni 3 Sn 2 S 2 has a high area-specific capacitance of 0.67 mAh cm−2 at a current density of 2 mA cm−2. Impressively, the hybrid supercapacitor assembled with Ni 3 Sn 2 S 2 /Ni foam cathode and commercial activated carbon anode delivers a maximum energy density of 4.65 mWh cm−3 at a power density of 29.64 mW cm−3. Two devices in series can lit up 22 blue Light-Emitting Diodes more than 130 min. On the strength of outstanding electrochemical performances, Ni 3 Sn 2 S 2 is a novel and promising electrode material for supercapacitor. [ABSTRACT FROM AUTHOR]

Metal sulfides has long been deemed as advanced anode material for sodium-ion batteries (SIBs). However, the intrinsic defects (e.g. , poor electrical conductivity and large volume variation) impede this material to reach the expectations of practical application. Here, we designed a unique chain mail Sb 2 S 3 /MoS 2 heterostructure based on one step sulfidation of the hydrangea-like Sb 2 MoO 6 precursor and the obtained Sb 2 S 3 /MoS 2 heterostructure exhibits large specific surface area as well as well-distributed heterointerfaces between Sb 2 S 3 and MoS 2 among the whole composite. The introduction of band engineering modulates electronic states of heterointerfaces, which induced built-in electrical field for accelerated interfacial charge transportation. Meanwhile, the in-situ formed nitrogen-rich carbon chain mail can not only facilitate electron migration and stabilize the active interfaces of Sb/Mo/Na 2 S intermediate phases, but also provide enhanced mechanical strength to accommodate volume expansion over sodiation, rendering admirable structure stability. Attributed to these superiorities, the as-developed SIBs exhibit an enhanced cycling performance of 411.5 mAh g-1 over 650 cycles at 5 A g-1. This work opens a new pathway for the material engineering strategy to design chain mail heterostructured material towards excellent performance. [Display omitted] • Chain mail heterostructured hydrangea-like Binary Metal Sulfides (Sb 2 S 3 /MoS 2) is prepared through on step sulfidation. • The advantages of spatial confinement effects and multicomponent interaction. • Na+ storage mechanism has been clearly revealed by in-situ characterization. • The heterostructure exhibits superior rate capability and excellent cycling stability as SIB anode. [ABSTRACT FROM AUTHOR]

In recent years, the development of lithium-ion batteries (LIBs) with high energy density has become one of the important research directions to fulfill the needs of electric vehicles and smart grid technologies. Nowadays, traditional LIBs have reached their limits in terms of capacity, cycle life, and stability, necessitating their further improvement and development of alternative materials with remarkably enhanced properties. A nitrogen-containing carbon nanotube (N-CNT) host for bimetallic sulfide (NiCo 2 S 4 ) is proposed in this study as an anode with attractive electrochemical performance for LIBs. The prepared NiCo 2 S 4 /N-CNT nanocomposite exhibited improved cycling stability, rate performance, and an excellent reversible capacity of 623.0 mAh g -1 after 100 cycles at 0.1 A g -1 and maintained a high capacity and cycling stability at 0.5 A g -1 . The excellent electrochemical performance of the composite can be attributed to the unique porous structure, which can effectively enhance the diffusivity of Li ions while mitigating the volume expansion during the charge-discharge processes.

Many binary metal oxides possess poor conductivity and ion diffusion efficiency, even though they have a high theoretical capacity as secondary battery anodes. Herein, we present a double binary metal sulfide composing of ZnCo 2 S 4 /NiCo 2 S 4 growing on carbon cloth, which was derived from a Zn–Co–Ni metal organic foam. Compared to the ZnCo 2 O 4 /NiCo 2 O 4 , the ZnCo 2 S 4 /NiCo 2 S 4 anodes exhibit an obviously improved electrochemical performance including a high areal capacity of 2.4 mAh cm−2 after cycling for 100 times at 0.36 mA cm−2, and a Coulombic efficiency of 99.9%. A well-recoverable rate-performance is also presented. In addition, the enhancement mechanism is investigated by using density functional theory simulations, which show the density of states and Li ion diffusion energies of the ZnCo 2 S 4 /NiCo 2 S 4 are improved compared to ZnCo 2 O 4 /NiCo 2 O 4. It is expected that the high-performance hybrid and the theoretical enhancement mechanism would enable them to find important applications for developing emerging energy-storage materials. A fast electron-transfer and ion-diffusion binary metal sulfide hybrid anode consisting of ZnCo 2 S 4 /NiCo 2 S 4 derived from MOFs was presented. Image 1 • A novel binary metal sulfide hybrid is reported. • Binary metal sulfides derived from MOFs are achieved. • Sulfide hybrid anodes exhibit a high lithium-storage performance. • DFT simulations confirm improvement of electron and ion transportation. [ABSTRACT FROM AUTHOR]

• Ni-Bi-S nanosheets/Ni foam are used as cathodes for supercapacitors for the first time. • Ni-Bi-S shows high specific capacitance, rate capability and cyclic stability. • Ni-Bi-S//CC asymmetric supercapacitors exhibit high energy density and power density. Supercapacitors are attracting tremendous interests in electrochemical energy storage and binary metal sulfides are attracting increasing attention due to higher electrochemical activities over their monometal counterparts. In this report, we show a novel Ni-Bi-S nanosheets/Ni foam electrode with superior performance for supercapacitors. In the synthetic process, Ni foam is utilized as current collector as well as Ni source for the Ni-Bi-S. Bi source plays a crucial role to achieve desired morphology for the Ni-Bi-S and uniform nanosheets network can be obtained by controlling the amount of the Bi (NO 3) 2. The Ni-Bi-S nanosheets/Ni electrode demonstrates a high specific capacitance of 4.81 F/cm2 at 5 mA/cm2 and an outstanding cycling performance. After 3000 cycles, 97.6% of the initial capacitance can be retained at 20 mA/cm2 and the retention is still as high as 83.4% even after 6500 cycles. An asymmetric supercapacitor constructed with Ni-Bi-S cathode and commercial conductive cloth (CC) anode demonstrates with a high energy density of 2.96 mWh/cm3 and a good retention rate after 2000 cycles. [ABSTRACT FROM AUTHOR]

Engineering nanostructured architecture with a hierarchically arranged active surface is regarded as an effective strategy to develop advanced electrode materials. Herein, nanosheet-built MnCo 2 S 4 micro-disks with abundant nano-pores are synthesized and uniformly dispersed on a three-dimensional nitrogen-doped carbon matrix (3DNC). In the resultant 3DNC@MnCo 2 S 4 composite architecture, N-doped carbon network provides interconnected and shortened pathways for fast ion transmission and charge transfer, and the nanosheet-built MnCo 2 S 4 disks allow the efficient Faradaic redox process through the increased active surface. Due to the compositional and structural advantages, prepared 3DNC@MnCo 2 S 4 composite architecture delivers a superior electrochemical capacitive performance than 3DNC@MnCo 2 O 4 and other sulphospinel-based electrodes (including a high specific capacitance of 1812 F g−1 at 1A g−1, and a high rate performance of 82.9% capacitance retention at 20 A g−1). When assembled into hybrid supercapacitor device, the 3DNC@MnCo 2 S 4 //AC HSC also exhibits a high energy density of 68.8 Wh kg−1 at the power density of 800 W kg−1 and excellent cycling stability (82% capacitance retention after 5000 cycles at the current density of 10 A g−1). The facile yet efficient construction of this 3D porous electrode provides an innovative method for developing high-performance energy storage devices. [ABSTRACT FROM AUTHOR]

Metal sulfides have been the subject of extensive research owing to their electro-optical properties that are suitable for photovoltaic applications. In particular, low-cost binary metal sulfides including Sb 2 S 3, SnS, PbS, Cu 2 S, Ag 2 S, Bi 2 S 3 and FeS 2 have been of interest as light absorbing materials in thin film solar cells. Despite numerous efforts devoted to the study of these materials over several decades, many technical issues and obstacles are yet to be overcome to render binary metal sulfides become a leading player in the area of thin film solar cells. One such issue is the low efficiency of solar cells built with binary metal sulfides, and hence, it is imperative to obtain a deeper understanding of the key mechanisms responsible for the loss of efficiency of such solar cells to achieve rapid improvement in the device performance. In this review, we describe the general technical progress of thin film solar cells based on binary metal sulfides and highlight the existing technical challenges toward improving the quality of the absorber films, junction characteristics, and device structure. [ABSTRACT FROM AUTHOR]

Porous core-shell CuCo 2 S 4 nanospheres that exhibit a large specific surface area, sufficient inner space, and a nanoporous shell were synthesized through a facile solvothermal method. The diameter of the core-shell CuCo 2 S 4 nanospheres is approximately 800 nm" the radius of the core is about 265 nm and the thickness of the shell are approximately 45 nm, respectively. On the basis of the experimental results, the formation mechanism of the core-shell structure is also discussed. These CuCo 2 S 4 nanospheres show excellent Li storage performance when used as anode material for lithium-ion batteries. This material delivers high reversible capacity of 773.7 mA h g -1 after 1000 cycles at a current density of 1 A g -1 and displays a stable capacity of 358.4 mA h g -1 after 1000 cycles even at a higher current density of 10 A g -1 . The excellent Li storage performance, in terms of high reversible capacity, cycling performance, and rate capability, can be attributed to the synergistic effects of both the core and shell during Li + ion insertion/extraction processes., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)