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The reuse of activated sludge as a solid waste is severely underutilized due to the limitations of traditional treatment and disposal methods. Given that, the sulfur-containing activated sludge catalyst doped with cobalt (SK-Co(1.0)) was successfully prepared by one-step pyrolysis and calcinated at 850 ℃. The generation of CoS x was successfully characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), indicating that the sulfur inside the sludge was the anchoring site for the externally doped cobalt. Cobalt (Ⅱ) (Co2+), as the main adsorption site for peroxymonosulfate(PMS), formed a complex (SK-Co(1.0)-PMS*) and created the conditions for the generation of surface radicals. The SK-Co(1.0)/PMS system showed high degradation efficiency and apparent rate constants for Sulfamethoxazole (SMX) (91.56% and 0.187 min−1) and Sulfadiazine (SDZ) (90.73% and 0.047 min−1) within 10 min and 30 min, respectively. Three sites of generation of 1O 2 , which played a dominant role in the degradation of SMX and SDZ in the SK-Co(1.0)/PMS system, were summarized as：sulfur vacancies (SVs), the Co3+/Co2+ cycles promoted by sulfur(S) species, oxygen-containing functional groups (C-O). The degradation mechanisms and pathways had been thoroughly investigated using DFT calculations. In view of this, a new idea for the resource utilization of activated sludge solid waste was provided and a new strategy for wastewater remediation was proposed. [Display omitted] • Sulfur inside activated sludge anchored exogenous cobalt. • In-solution and surface radicals were generated by (SK-Co(1.0)-PMS*). • Multiple modes generated the dominant 1O 2. • The degradation product from SDZ and SMX obtained low ecotoxicity. • DFT calculation was used to explain the degradation mechanism and path. [ABSTRACT FROM AUTHOR]

High concentrations of metals and sulfates in acid mine drainage (AMD) are the cause of the severe environmental hazard that mining operations pose to the surrounding ecosystem. Little study has been conducted on the cost-effective biological process for treating high AMD. The current research investigated the potential of the proposed carbon source and sulfate reduction bacteria (SRB) culture in achieving the bioremediation of sulfate and heavy metals. This work uses individual and combinatorial bioaugmentation and bio-stimulation methods to bioremediate acid-mine-influenced groundwater in batch microcosm experiments. Bioaugmentation and bio-stimulation methods included pure culture SRB (Desulfovibrio vulgaris) and microsized oil droplet (MOD) by emulsifying corn oil. The research tested natural attenuation (T 1), bioaugmentation (T2), biostimulation (T3), and bioaugmentation plus biostimulation (T4) for AM-contaminated groundwater remediation. Bioaugmentation and bio-stimulation showed the greatest sulfate reduction (75.3%) and metal removal (95–99%). Due to carbon supply scarcity, T1 and T2 demonstrated 15.7% and 27.8% sulfate reduction activities. Acetate concentrations in T3 and T4 increased bacterial activity by providing carbon sources. Metal bio-precipitation was substantially linked with sulfate reduction and cell growth. SEM-EDS study of precipitates in T3 and T4 microcosm spectra indicated peaks for S, Cd, Mn, Cu, Zn, and Fe, indicating metal-sulfide association for metal removal precipitates. The MOD provided a constant carbon source for indigenous bacteria, while Desulfovibrio vulgaris increased biogenic sulfide synthesis for heavy metal removal. [Display omitted] • Bioaugmentation and bio-stimulation approach to remediate acid mine drainage (AMD) influenced groundwater. • Microsized oil droplets (MOD) based Emulsified corn oil was used as a carbon source. • High removal of heavy metals and sulfate have been achieved. • Metal bio-precipitation was linked with sulfate reduction and SRB cell growth. [ABSTRACT FROM AUTHOR]

• A high-performance MoS x adsorbent with sulfur-rich feature was prepared. • The number of unsaturated coordination sulfur sites decides Hg0 adsorption. • The as-prepared MoS x -6–220 possesses the best performance for Hg0 capture. • The final adsorption product is formed through a transformation from Hg-Mo amalgam to HgS. Gaseous elemental mercury (Hg0) removal is desirable for the green and high-quality development of nonferrous metal smelting industry. Developing a simple and feasible method to prepare high-performance adsorbent is still challenging. Herein, a sulfur enrichment strategy was proposed to prepare molybdenum sulfide (MoS x) with abundant unsaturated coordination sulfur sites. Benefiting the sulfur-rich feature, the Hg0 sequestration capacity of prepared MoS x is markedly enhanced compared with commercial MoS 2. The characterization results of MoS x demonstrate an ideal structural property and abundant unsaturated sulfur ligands, which assures a desired performance for Hg0 adsorption. Among these adsorbents, MoS x -6–220 exhibits the best Hg0 capture performance, which presents a Hg0 adsorption efficiency of nearly 100 % and average adsorption rate of 6.41 μg/g/min. The theoretical saturated adsorption capacity of MoS x -6–220 reaches 53.03 mg/g, higher than other conventional metal sulfides. The typical compositions in the smelting flue gas have almost little impact on Hg0 adsorption. The experimental and characterization results confirm that the impressive performance is primarily attributed to the enormous quantity of unsaturated coordination sulfur sites, rather than S/Mo stoichiometry. Moreover, the density functional theory calculation results further demonstrate the high adsorption activity of unsaturated coordination sulfur site for Hg0 immobilization. Hg0 adsorption pathway shows that Hg0 is first adsorbed on the top of Mo atom in the form of Hg-Mo amalgam, then the adsorbed Hg would migrate to unsaturated coordination sulfur ligand and bond with it to form stable HgS product, thereby realizing the permanent immobilization of Hg0. This work not only provide a promising strategy to prepare high-performance metal sulfide adsorbents, but also give deep insight into the Hg0 adsorption and conversion mechanism at the molecular level. [ABSTRACT FROM AUTHOR]

The pollution of antibiotics and heavy metals in water environment is considered to be an urgent environmental problem. However, designing a photocatalyst that can simultaneously remove these contaminants remains a challenge. 0D/2D Cd 0.5 Zn 0.5 S/Ti 3 C 2 (CZSMX) hybrids were fabricated by uniformly coating Cd 0.5 Zn 0.5 S (CZS) nanospheres on the surface of Ti 3 C 2 nanosheets. The removal efficiency of the suitable CZSMX hybrid on tetracycline hydrochloride (100 mg/L), 7-amino-cephalosporin (100 mg/L), and Cr(VI) (50 mg/L) is 92%, 97%, and 72%, respectively. Meanwhile, it still exhibits excellent photocatalytic removal activity in the mixed contaminants solution. Additionally, CZSMX-3 exhibits outstanding physical and chemical stability after 5 cycles. Importantly, the enhanced photocatalytic activity of CZSMX is attributed to the accelerated charge carrier separation due to the excellent electrochemical and photochemical properties of Ti 3 C 2. Overall, this study provides a strategy for the efficient collaborative removal of antibiotics and heavy metal from wastewater by photocatalysis of metal sulfide based photocatalysts. • 0D/2D Cd 0.5 Zn 0.5 S/Ti 3 C 2 Schottky junction was fabricated by hydrothermal method. • CZSMX effectively improves the defects of photocorrosion and the recombination of photogenerated carriers of metal sulfide. • MXCIS possesses the excellent photocatalytic activity on the collaborative removal of TC, 7-ACA, and Cr(VI). • Ti 3 C 2 /CdIn 2 S 4 exhibits excellent physical and chemical stability after many cycles. [ABSTRACT FROM AUTHOR]

Replacement of exhaustible and harmful resources used as solid lubricants is required for sliding elements such as plain bearings. In particular, the substitution of lead containing in the lead bronze is considered an urgent task. Therefore, in this study, attention was focused on metal sulfides (Cu2S, Cu5FeS4, SnS, TiS2, etc) as a substitute material for lead. After synthesis of sulfide and preparation of sintered body, friction and abrasion test was carried out and applicability as solid lubricant was investigated. The tribological properties of the dry conditions were evaluated by a journal type high speed tester. As a result, the friction coefficient of the bronze specimen without sulfide was about 0.3, whereas the bronze specimen containing sulfide showed a friction coefficient of about 0.1, indicating that the sulfide reduced the frictional resistance. Among them, the specimens containing Cu2S and Cu5FeS4 exhibited a lower friction coefficient. It is considered that this is influenced not only by the effect of hardness but also by film formation by sulfide.

Abstract An in situ coupling strategy to prepare Co9S8/S and N dual-doped graphene composite (Co9S8/NSG) has been proposed. The key point of this strategy is the function-oriented design of organic compounds. Herein, cobalt porphyrin derivatives with sulfo groups are employed as not only the coupling agents to form and anchor Co9S8 on the graphene in situ, but also the heteroatom-doped agent to generate S and N dual-doped graphene. The tight coupling of multiple active sites endows the composite materials with fast electrochemical kinetics and excellent stability for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The obtained electrocatalyst exhibits better activity parameter (ΔE = 0.82 V) and smaller Tafel slope (47.7 mV dec−1 for ORR and 69.2 mV dec−1 for OER) than commercially available Pt/C and RuO2. Most importantly, as electrocatalyst for rechargeable Zn–air battery, Co9S8/NSG displays low charge–discharge voltage gap and outstanding long-term cycle stability over 138 h compared to Pt/C–RuO2. To further broaden its application scope, a homemade all-solid-state Zn–air battery is also prepared, which displays good charge–discharge performance and cycle performance. The function-oriented design of N4-metallomacrocycle derivatives might open new avenues to strategic construction of high-performance and long-life multifunctional electrocatalysts for wider electrochemical energy applications.

Abstract A general one-pot approach is developed to synthesize a series of binary metal sulfide nanocrystals (NCs) including PbS, Cu2S, ZnS, CdS, Ag2S, and ternary CuInS2 and CdS:Cu(I) NCs. This synthetic approach involves thermal decomposition of the mixture of inorganic metal salts and n-dodecanethiol (DDT) without pre-synthesis of any organometallic precursors. In this method, layered metal-thiolate compound is formed at the beginning of the reaction and then this intermediate compound is decomposed into small particles, leading to further growth as the reaction time increases. The as-obtained CdS NCs exhibits a broad but weak surface-state emission, and the Cu(I) doping leads to a red-shift of the emission band due to the Cu(I)-related emission. It is expected that this one-pot approach can be extended to prepare multinary metal sulfide NCs.

As a typical two-dimensional layered metal sulfide, MoS2 has a high theoretical capacity and large layer spacing, which is beneficial for ion transport. Herein, a facile polymerization method is employed to synthesize polypyrrole (PPy) nanotubes, followed by a hydrothermal method to obtain flower-rod-shaped MoS2/PPy (FR-MoS2/PPy) composites. The FR-MoS2/PPy achieves outstanding electrochemical performance as a sodium-ion battery anode. After 60 cycles under 100 mA g−1, the FR-MoS2/PPy can maintain a capacity of 431.9 mAh g−1. As for rate performance, when the current densities range from 0.1 to 2 A g−1, the capacities only reduce from 489.7 to 363.2 mAh g−1. The excellent performance comes from a high specific surface area provided by the unique structure and the synergistic effect between the components. Additionally, the introduction of conductive PPy improves the conductivity of the material and the internal hollow structure relieves the volume expansion. In addition, kinetic calculations show that the composite material has a high sodium-ion transmission rate, and the external pseudocapacitance behavior can also significantly improve its electrochemical performance. This method provides a new idea for the development of advanced high-capacity anode materials for sodium-ion batteries.

Metal sulfides serve as sinks of toxic heavy metals in anoxic sediments. Suspension of metal sulfides to oxic water columns may cause their oxidative dissolution, leading to the release of toxic heavy metal ions. Ubiquitous natural organic matter (NOM) could adsorb on the surfaces of metal sulfides and influence their dissolution. In this study, the dissolution of suspended PbS, CuS, and ZnS with different levels of adsorbed NOM was investigated. The rates of metal release showed the following order after normalization by the available surface areas: PbS > CuS > ZnS. The adsorbed NOM was found to inhibit the oxidative dissolution of PbS and ZnS; the degree of inhibition was enhanced by increased levels of NOM adsorption. In contrast, the dissolution of CuS was found to increase and then decrease with increased levels of NOM adsorption. These results show that adsorbed NOM can promote metal release via ligand-induced dissolution, as well as inhibit metal release by forming a barrier against oxygen and proton attacks. The relative importance of these processes is metal specific and governs the overall impacts of NOM adsorption on the dissolution of metal sulfides. The results imply that remobilization of heavy metals from contaminated sediments during intensified storm events should be carefully evaluated in terms of metals of concern and levels of organic matter adsorption. [ABSTRACT FROM AUTHOR]

Mercury emission from industrial activities has become a major environmental health concern, because mercury is one of the most toxic metals encountered in the environment. Elemental mercury is the dominant Hg species in gas streams. Adsorption is regarded as a practical technique for Hg0 removal, for which developing efficient and economic adsorbents are needed. Chalcogenides have recently gained increasing research interest owing to their high binding affinity for Hg0. Chalcogen-based adsorbents include S-modified adsorbents, H2S- and SO2-activated adsorbents, polysulfide chalcogels, mineral sulfides and metal selenides. This article reviews chalcogen-based adsorbents for Hg0 capture from gas streams, with focus on removal performances, mechanisms, advantages and disadvantages. Results show that S modification, and H2S and SO2 activation generate a great variety of active sulfur species on the adsorbent surface, resulting in enhanced Hg0 removal activity. Sulfur species include elemental sulfur, sulfide, thiophene and sulfate. Nonetheless, removal efficiency decreases to some extent due to the presence of acidic flue gas components and steam. On the other hand, mineral sulfides and metal selenides exhibit outstanding Hg0 removal performances with fast adsorption rate, high mercury capacity and excellent resistance to SO2 and H2O. Yet most mineral sulfides and metal selenides perform well below 100 °C, which might limit industrial applications. [ABSTRACT FROM AUTHOR]

Metal sulfide nanomaterials (MeSNs) are a novel class of metal-containing nanomaterials composed of metal ions and sulfur compounds. During the past decade, scientists found that the MeSNs engineered by specific approaches not only had high biocompatibility but also exhibited unique physicochemical properties for cancer therapy, such as Fenton catalysis, light conversion, radiation enhancement, and immune activation. To clarify the development and promote the clinical transformation of MeSNs, the first section of this paper describes the appropriate fabrication approaches of MeSNs for medical science and analyzes the features and limitations of each approach. Secondly, we sort out the mechanisms of functional MeSNs in cancer therapy, including drug delivery, phototherapy, radiotherapy, chemodynamic therapy, gas therapy, and immunotherapy. It is worth noting that the intact MeSNs and the degradation products of MeSNs can exert different types of anti-tumor activities. Thus, MeSNs usually exhibit synergistic antitumor properties. Finally, future expectations and challenges of MeSNs in the research of translational medicine are spotlighted. [ABSTRACT FROM AUTHOR]

The tunable band structure and unique electrochemical properties of metal sulfide nanocrystals make them important components for the display devices and energy conversion. Nevertheless, the existing synthesis approaches meet issues in terms of time/energy consumption as well as the use/production of toxic materials, so it is highly desired to explore a more facile and controllable green approach for metal sulfide synthesis. Herein, we demonstrated a formamide-assisted approach for the synthesis of six monometallic sulfides (CdS, CuS, NiS2, ZnS, Ag2S, and PbS) and one iron-doped NiS2 (NixFe1–xS2) in nanoscale, offering an ecofriendly, fast, and general strategy in the concepts of green chemistry. [ABSTRACT FROM AUTHOR]

Two-dimensional transition-metal dichalcogenides have gained increasing concerns because of their distinct structural features and also display great potential in mercury removal. Herein, a defect-rich MoS 2 nanosheet is synthesized by using hydrothermal method and applied for adsorptive capture of elemental mercury (Hg0) in simulated flue gas at low temperature. It exhibits excellent Hg0 removal performance due to its ultra-thin lamellar and defective structures with ample exposed adsorption sites. The Hg0 removal efficiency of the defective MoS 2 nanosheet is all above 93% when the reaction temperature is within 25–150 °C. Besides, presence of NO has no influence on Hg0 removal, while SO 2 subtly reduces the Hg0 removal efficiency due to competitive adsorption. Mo4+, S2−, and S 2 2− ions take part in the Hg0 removal process, which transfers Hg0 into Mo–Hg amalgam and HgS. The process of Hg0 adsorption on the defective MoS 2 nanosheet obeys the pseudo-first-order and pseudo-second-order kinetic model. • A defective MoS 2 nanosheet is synthesized via one-pot hydrothermal method. • The MoS 2 nanosheet performs excellently toward Hg0 capture at low temperature. • NO and SO 2 exert nearly no impacts on Hg0 removal over the MoS 2 nanosheet. [ABSTRACT FROM AUTHOR]

The effect of sulfiding agent and sulfidation temperature on nickel catalysts supported on MgAl2O4 were investigated for propane dehydrogenation. The catalysts were prepared by reduction of NiO/MgAl2O4, followed by sulfidation using (NH4)2SO4 (S1), (NH4)2S (S2), and DMSO (S3) as sulfiding agents. The catalysts were sulfided at 200 °C, 400 °C, and 550 °C to form Ni/MgAl2O4-Sx-y, where x and y represent the sulfiding agent and sulfidation temperature, respectively. Physiochemical properties of the catalysts were characterized by XRD, BET, SEM, TEM, and TGA to investigate the type of nickel-sulfur species, surface area, morphology, particle size, and stability of the catalysts. Structural and textural properties revealed that the anion present on the sulfiding agent as well as the sulfidation temperature affect both the type and the strength of the Ni-S species. For the S1 catalysts, the SO42− ion interacted with the support to form MgSO4, while the S2− ion on the S2 and S3 catalysts was responsible for the formation of the Ni3S2 phase. The sulfidation temperature contributed to the %S present on each catalyst. Although the catalysts sulfided by S3 contained the least %S, Ni/MgAl2O4-S3-550 displayed the best catalytic performance as a result of the higher particle dispersion and stronger Ni-S interaction compared to S1 and S2 catalysts.

All-solid-state sodium secondary batteries are expected to be low-cost, next-generation batteries. NiS2 and FeS2 are potential candidates as positive electrode materials owing to their high theoretical capacities. However, it is difficult to achieve sufficient capacity with bulk FeS2. In this study, pyrite Ni1−xFexS2 (x = 0, 0.3, 0.5, 0.7, 0.9, and 1) electrodes are prepared by a mechanochemical process. The all-solid-state sodium cells with Ni1−xFexS2 show higher discharge–charge potentials than those with NiS2, and higher capacities than those with FeS2. In addition, Ni1−xFexS2 exhibits a higher rate performance than those of NiS2 and FeS2. The all-solid-state cells using Ni1−xFexS2 (x = 0.3, 0.5, and 0.7) are discharged and charged with a high capacity of approximately 390 mAh g−1, without significant capacity fading for at least 30 cycles. The solid-solution formation of NiS2 and FeS2 results in lower material cost, higher rate performance, higher discharge–charge potential than those of NiS2, and higher capacity than that of FeS2. Pyrite Ni1−xFexS2 is a promising positive electrode material for all-solid-state sodium secondary batteries.

Metal sulfides are emerging as a promising anode material for sodium‐ion batteries with high reversible capacities and fast reaction kinetics, but achieving long‐cycling‐life remains a great challenge. Here, taking cobalt sulfide as an example, its electrochemical sodium‐ion storage failure phenomenon is first reported, which indicates that the battery cannot reach the cut‐off voltage during charging. Detailed analyses demonstrate that such failure may originate from the dissolution and escape of polysulfide intermediates, further reacting with the released copper‐ions from the current collector and inducing the occurrence of the shuttle effect. Based on the explored failure mechanism, a sulfur‐doped carbon matrix with polar carbon sulfur bonds, which can firmly immobilize the dissolved polysulfides, is deliberately introduced into the Co1−xS active particles (Co1−xS/s‐C) to improve their cycle stability. Consequently, the cycle life of the Co1−xS/s‐C anode for sodium‐ion storage is extended from the original 125 to present 2000 cycles, even at high‐rate current densities. Moreover, utilizing the carbon current collector instead of traditional copper can effectively delay the occurrence of the failure phenomenon. The present work promotes better fundamental understanding of the structural evolution of metal sulfide anodes during cycles, and the solution strategy can be extended to apply in other metal sulfides (ZnS, NiS). [ABSTRACT FROM AUTHOR]

• ZnS/MoS2 composite photocatalysts were synthesized by a one-step hydrothermal process. • Defects in the structure of ZnS were observed by TEM analysis. • H 2 yield was increased in the materials containing Mo in comparison with bare ZnS. • Increase of activity was attributed to ZnS/MoS2 synergy and the formation of defects. ZnS/MoS 2 composite material was prepared by one-step solvothermal method at different molybdenum concentration. The structural properties of the composite material were analyzed by XRD, UV–vis DRS, TEM and XPS techniques, and the photocatalytic was evaluated for the hydrogen production under UV irradiation. The hydrogen yield reaches 606 μmol h−1 g−1 for the material with 10% of molybdenum, which was 30 and 50% superior than that obtained using MoS 2 and ZnS as photocatalyst, respectively. The increase in the photocatalytic activity may be associated to a synergistic effect produced by the interaction between ZnS and MoS 2 , as well as the formation of defects in the structure of ZnS, due to sulfur vacancies produced during the synthesis, which could be observed in the TEM analysis of the composite material. [ABSTRACT FROM AUTHOR]

Engineering phase transition in micro-nanomaterials to optimize the dielectric properties and further enhance the electromagnetic microwave absorption (EMA) performance is highly desirable. However, the severe synthesis conditions restrict the design of EMA materials featuring controllable phases, which hinders the tunability of effective absorption bandwidth (EAB) and leads to an unclear loss mechanism. Herein, a seed phase decomposition-controlled strategy is proposed to induct nickel sulfide (NiS x ) absorbers with controllable phases and hollow sphere nature. Transmission electron microscopy holography and theoretical calculations evidence that the reconstruction of atoms in phase transition induces numerous heterogeneous interfaces and lattice defects/sulfur vacancies to cause varied work functions and local electronic redistribution, which contributes to reinforced dielectric polarization. As a result, the optimized NiS 2 /NiS heterostructure enables enhanced EM attenuation capability with a wide EAB of 5.04 GHz at only 1.6 mm, compared to that of NiS 2 and NiS. Moreover, the correlation between EAB and NiS phase content is demonstrated as the "volcano" feature. This study on the concept of phase transition of micro-nanomaterials can offer a novel approach to constructing highly efficient absorbers for EMA and other functionalities., (© 2023 Wiley‐VCH GmbH.)

Developing efficient metal sulfides for pure water splitting is a challenging topic in the field of photocatalysis. Herein, inspired by natural photosynthesis, an all‐solid‐state Z‐scheme photocatalyst was constructed with Cd0.9Zn0.1S (CZS) for water reduction, red phosphorus (RP) for water oxidation, and metallic CoP as the electron mediator. RP@CoP core‐shell nanostructures were uniformly attached on the CZS nanorods, which gave rise to multiple monodispersed nanojunctions. The integrated Z‐scheme nanosystem exhibited an apparent quantum efficiency of 6.4 % at 420 nm for pure water splitting. Theoretical analysis and femtosecond transient absorption results revealed that the impressive performance was mainly due to efficient hole transfer of CZS, resulting from the intimate atomic contacts between CoP mediator and photocatalysts, together with favorable band alignment. Meanwhile, the multiple monodispersed Z‐scheme nanojunctions could provide abundant reaction sites, which was also important for the boosted activity. [ABSTRACT FROM AUTHOR]

Constructing composite photocatalyst is an efficient way to realize the application of photocatalysis owing to the fast separation of photocarriers. In this report, we constructed a novel ternary noble-metal free S/Ni 12 P 5 /Cd 0.5 Zn 0.5 S (S/Ni 12 P 5 /CZS) composite which displayed much higher activity than binary Ni 12 P 5 /CZS, S/CZS and especially CZS solid solution for H 2 generation under visible light illumination (λ ≥ 420 nm). 15% S/Ni 12 P 5 /CZS showed the highest activity of H 2 production (525.5 μmol h−1) among all the samples due to the optimal separating efficiency of photocarriers, and its apparent quantum efficiency is 4.37% at 420 nm. In the photocatalytic process, the photogenerated electrons of CZS solid solution quickly moved to elemental S through Ni 12 P 5 as solid electron transfer mediator, resulting in high separation efficiency of photocarriers and outstanding activity of H 2 production over S/Ni 12 P 5 /CZS. Moreover, S/Ni 12 P 5 /CZS presented excellent stability after 10 runs recycling experiment. The significant finding of this paper provides new strategy to rationally design composite photocatalyst for efficiently splitting water to generate clean energy H 2. • Novel S/Ni 12 P 5 /Cd 0.5 Zn 0.5 S (S/Ni 12 P 5 /CZS) composite was firstly constructed. • S/Ni 12 P 5 /CZS showed higher activity than Ni 12 P 5 /CZS and S/CZS for H 2 generation. • S/Ni 12 P 5 /CZS possessed the highest photo-charge separation efficiency. • The photogenerated electrons of CZS transferred across Ni 12 P 5 to elemental S. [ABSTRACT FROM AUTHOR]

Hybrid material-based resistive random-access memories (ReRAM) have gained immense popularity as data storage devices owing to their high scalability, easy processability, and cost-effectiveness. Herein, we report the resistive switching (RS) performances of various nanohybrid materials, consisting of metal-sulfide (ZnS, CuS, and SnS)-grafted reduced graphene oxide (rGO), by embedding into a thin polymeric layer. An active layer with a sandwich electrode configuration (ITO/nanohybrid-PMMA composites/Al) is realized for electrical studies. Additionally, the RS phenomena are modulated through precisely varying the concentration of nanohybrid-polymer composite fillers. The electrical studies display the bipolar-resistive switching properties along with an extremely low VSET/VRESET of ∼−0.44 ± 0.10/+0.50 ± 0.10 V. Also, a very low write/erase power consumption (PSET/PRESET) of ∼1.02 × 10<–5 / 1.18 × 10–5 Wcm–2 is obtained for the CuS-grafted rGO nanohybrid. Furthermore, a current ON/OFF (ION/IOFF) ratio of ∼103–104 is obtained for all the fabricated devices, which lowers the level of misreading in the nanohybrid devices. All the devices display excellent RS properties, especially low operating voltage, high reliability, and high persistency for optimum loading of nanofillers concentration ranging from 0.3 to 0.5 wt %. The interfacial synergistic effect coupled with trapping and detrapping of charge carriers is considered responsible for the observed resistive switching behavior. [ABSTRACT FROM AUTHOR]

A general method for preparing sandwiched nanostructures consisting of reduced graphene oxide (rGO) and metal sulfides is presented. As a demonstrating example, the sandwiched MoS2@rGO nanocomposites show a good electrochemical performance including a high reversible capability of 1345 mAh g−1 at 0.5 A g−1 over 400 cycles, and a superior rate performance. Moreover, this method has been verified to fabricate a large set of transition metal sulfides- and double metal sulfides-based rGO composites such as CoS@rGO, NiS@rGO, NiCo2S4@rGO, and CuCo2S4@rGO, enabling the preparing approach presented here applicable for many possible anode and cathode chemistries. Impact statement A general strategy for the fabrication of sandwiched nanostructures consisting of reduced graphene oxide (rGO) and metal sulfides for highly reversible Li-ion battery anode has been developed.

The development of nanomaterials with therapeutic and/or diagnostic properties has been an active area of research in biomedical sciences over the past decade. Nanomaterials have been identified as significant medical tools with potential therapeutic and diagnostic capabilities that are practically impossible to accomplish using larger molecules or bulk materials. Fabrication of nanomaterials is the most effective platform to engineer therapeutic agents and delivery systems for the treatment of cancer. This is mostly due to the high selectivity of nanomaterials for cancerous cells, which is attributable to the porous morphology of tumour cells which allows nanomaterials to accumulate more in tumour cells more than in normal cells. Nanomaterials can be used as potential drug delivery systems since they exist in similar scale as proteins. The unique properties of nanomaterials have drawn a lot of interest from researchers in search of new chemotherapeutic treatment for cancer. Metal sulfide nanomaterials have emerged as the most used frameworks in the past decade, but they tend to aggregate because of their high surface energy which triggers the thermodynamically favoured interaction. Stabilizing agents such as polymer and microgels have been utilized to inhibit the particles from any aggregations. In this review, we explore the development of metal sulfide polymer/microgel nanocomposites as therapeutic agents against cancerous cells.

Bimetallic hollow I -Cu 2 MoS 4 nanocubes are prepared by the solvothermal method with the Cu 2 O nanocubes as the sacrificial templates. Compared to the carbonate-based electrolyte, the ether-based electrolyte shows better compatibility with Cu 2 MoS 4 electrode, which shows high reversible capacity, superior rate performance and remarkably improved cycling performance. The ex-situ XRD analysis demonstrates the highly reversible electrochemical reaction in the ether-based electrolyte. Anode materials based on transition metal sulfides suffer from poor electrochemical reversibility, which limits their cycling stability. Herein, we synthesize hollow I -Cu 2 MoS 4 nanocubes composed of ultrathin nanosheets using a solvothermal method with Cu 2 O nanocubes as sacrificial templates. The presence of a surfactant is a key factor that prevents the structural collapse of the hollow cubic structure of Cu 2 MoS 4 and the formation of nanoplates. An ether-based electrolyte shows better compatibility with the Cu 2 MoS 4 electrode than a carbonate-based electrolyte, which is reflected in high reversible capacity, superior rate performance, and remarkably improved cycling performance. Ex-situ XRD analysis demonstrates a highly reversible electrochemical reaction in the ether-based electrolyte, which enhances the cycling stability. [ABSTRACT FROM AUTHOR]

Electrode materials with high energy densities and long‐lasting performances are crucial to durable and reliable electrochemical energy storage devices for modern information technologies (eg, Internet of things). In terms of supercapacitors, their low energy densities could be enhanced by using pseudocapacitive electrodes, but meanwhile, their ultralong lifetimes are compromised by the limited charge‐discharge cycling stabilities of pseudocapacitive materials. This review article discusses on the cycling instability issues of five common pseudocapacitive materials: conjugated polymers (or conducting polymers), metal oxides, metal nitrides, metal carbides, and metal sulfides. Specifically, the article includes the fundamentals of the failure modes of these materials, as well as thoroughly surveys the design rationales and technical details of the cycling‐stability‐boosting tactics for pseudocapacitive materials that reported in the literature. Additionally, promising opportunities, future challenges, and possible solutions associated with pseudocapacitive materials are discussed. [ABSTRACT FROM AUTHOR]

Simple and stable synthesis of transition metal sulfides and clarification of their growth mechanisms are of great importance for developing catalysts, metal‐air batteries and other technologies. In this work, we developed a one‐step facile hydrothermal approach to successfully synthesize NiS2 microspheres. By changing the experimental parameters, the reason that affects the formation of nanostructured spheres is investigated and discussed in detail, and the formation mechanism of microspheres is proposed innovatively. Furthermore, electrochemical testing results show that the 7 h‐NiS2 catalyst exhibits a remarkable oxygen evolution reaction (OER) activity with an overpotential of 311 mV at 10 mA cm−2 in 1.0 M KOH, superior to precious metal RuO2. The NiS2 catalyst also exhibits a robust durability. This work will contributes to the rational design and the understanding of growth mechanism of transition metal chalcogenide electrocatalysts for diverse energy conversion technologies. [ABSTRACT FROM AUTHOR]

Among novel nanostructured materials, transition metal chalcogenides (i.e., sulfides and selenides) emerged as promising candidates due to their unique electrochemical properties. The following study presents a facile synthesis approach of Bi2S3 nanostructures using solvent mixtures of ethanol and water with different volume ratios and ammonium sulfide as a sulfur precursor. The resultant bismuth sulfides were characterized by field-emission scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and nitrogen sorption at 77 K. The adjustment of the solvent mixture revealed the possibility of customizing the crystalline structure from amorphous to fully crystalline, as well as the morphology of the Bi2S3, which subsequently influenced on their electrochemical properties. Bi2S3 synthesized in a solvent mixture of ethanol-to-water volume ratio 1:2 (Bi2S3-EW12) exhibited almost fully crystalline structure and nanoplatelet-like morphology, which translated to the best electrochemical performance. Bi2S3-EW12 achieved specific capacity of 748 C g−1 in an aqueous 6 mol L−1 KOH electrolyte and maintained the highest capacity value at a large current density of 20 A g−1. [ABSTRACT FROM AUTHOR]

Metal oxides or sulfides are considered to be one of the most promising CO2 reduction reaction (CO2RR) precatalysts, owing to their electrochemical conversion in situ into highly active electrocatalytic species. However, further improvement of the performance requires new tools to gain fine control over the composition of the active species and its structural features [e.g. grain boundaries (GBs) and undercoordinated sites (USs)], directly from a predesigned template material. Herein, we describe a novel electrochemically driven cation exchange (ED‐CE) method that enables the conversion of a predesigned CoS2 template into a CO2RR catalyst, Cu2S. By means of ED‐CE, the final Cu2S catalyst inherits the original 3 D morphology of CoS2, and preserves its high density of GBs. Additionally, the catalyst's phase structure, composition, and density of USs were precisely tuned, thus enabling rational design of active CO2RR sites. The obtained Cu2S catalyst achieved a CO2‐to‐formate Faradaic efficiency of over 87 % and a record high activity (among reported Cu‐based catalysts). Hence, this study opens the way for utilization of ED‐CE reactions to design advanced electrocatalysts. [ABSTRACT FROM AUTHOR]

The kinetics of the roasting of iron and copper sulfides in a pulsating layer was studied, and the kinetic parameters of the processes were determined. The determination of the order of the roasting reactions and activation energy in the MeS - Na2CO3 - O2 system is based on the differential method. Using the dependences of the degree of conver- sion of copper and iron sulfides in the reactor of the vibratory pulsating layer at a pulsation frequency of 50 Hz and a pulsation amplitude of 0,1 - 0,5 mm, the values of the apparent activation energy in the temperature ranges of 500 -- 550 - 600 °C were obtained for FeS 1,60 - 1,64 and for Cu2 S 1,44 - 2,41 J*mol. (CO2). [ABSTRACT FROM AUTHOR]

• Palladium nanoparticles favour over-hydrogenation in butyne hydrogenation. • In contrast, palladium sulfide catalyst is highly selectivity for butyne hydrogenation. • Pd 4 S offers greater than 90% alkene selectivity for both but-1-yne & but-2-yne as reactants. • DFT calculations show desorption of alkene is more favourable than hydrogenation. The partial hydrogenation of but-1-yne and but-2-yne was studied with a view to probing the difference between external and internal alkynes. Catalysts with Pd and Pd 4 S active phases were prepared on a carbon nanofiber support. Over the simple Pd catalyst over-hydrogenation was common which restricted alkene selectivity greatly – 25–35% depending on temperature. In contrast, the Pd 4 S active phase offered exceptional alkene selectivity (maximum of 92–93% alkene selectivity for both the external and internal alkyne). DFT calculations were subsequently used to rationalise this difference in product selectivity – sulfur appears to change the geometry of the active site in Pd 4 S and create a surface which favours alkene desorption relative to over-hydrogenation. This work further emphases the potential of palladium sulfide phases as an alternative to purely metallic palladium catalysts for partial alkyne hydrogenation. [ABSTRACT FROM AUTHOR]

High‐quality anodes are very important for the future generations of rechargeable sodium‐ion batteries (SIBs). Metal sulfides (MSs) as a promising anode have attract tremendous attentions and shown impressive results in terms of versatile material species, low‐cost raw materials, and excellent electrochemical performance. In particular, the unique 2D few‐layer structure of MSs provides a new view for overcoming some challenges appeared on anodic electrodes, such as volume change, structure collapse, high‐rate capability, and confinement of phase‐variation of MSs. Here, we review some of the recent scientific advances in 2D MSs, including the synthetic strategies, electronic structure, and electro‐chemical performance on SIBs. [ABSTRACT FROM AUTHOR]

Photocatalysis, which is the catalyzation of redox reactions via the use of energy obtained from light sources, is a topic that has garnered a lot of attention in recent years as a means of addressing the environmental and economic issues plaguing society today. Of particular interest are photosynthesis can potentially mimic a variety of vital reactions, many of which hold the key to develop sustainable energy economy. In light of this, many of the technological and procedural advancements that have recently occurred in the field are discussed in this review, namely those linked to: (1) photocatalysts made from metal oxides, nitride, and sulfides; (2) photocatalysis via polymeric carbon nitride (PCN); and (3) general advances and mechanistic insights related to TiO2-based catalysts. The challenges and opportunities that have arisen over the past few years are discussed in detail. Basic concepts and experimental procedures which could be useful for eventually overcoming the problems associated with photo-catalysis are presented herein. [ABSTRACT FROM AUTHOR]

With the rapid development of nanotechnology, metal sulfide nanoparticles have been widely detected in the environment including water, soils and sediments. Metal sulfides are considered as stable species in the environment, while transformation and risk of nanoparticles have attracted increasing attention due to their specific physicochemical properties compared to bulk materials. Here we review aggregation, sedimentation, chemical and biological transformations, and potential risk of silver sulfide (Ag2S), zinc sulfide (ZnS), copper sulfide (CuS), cadmium sulfide (CdS) and lead sulfide nanoparticles, and quantum dots such as ZnS and CdS. The review shows that both stability and risk of metal sulfide nanoparticles are highly dependent on environmental factors such as pH, inorganic salts and natural organic matter. [ABSTRACT FROM AUTHOR]

Metal sulfides with spinel structures have been considered as promising materials for supercapacitors and attracted increasing attentions of researchers over the past few years. However, inherent defects of metal sulfides such as poor electric conductivity and cyclic stability limit the practical application. Herein, we present a facile strategy to fabricate N-doped carbon coated spinel copper cobalt sulfide hollow spheres with remarkable electrochemical performance. A kind of Cu–Co coordination polymer spheres was utilized as template and metal precursor, polydopamine modified on the surface of the spheres was the source of N-doped carbon. The optimized hybrid materials exhibit high specific capacitance (1228 F g−1 at 1 A g−1) and outstanding cyclic stability (retaining 81.5% of the initial capacitance after 10000 cycles at 20 A g−1). The result demonstrates that this hybrid material is a promising electrode material to realize high performance supercapacitors. [ABSTRACT FROM AUTHOR]

Efficient non-noble metal catalysts for the oxygen evolution reaction (OER) are particularly important in the practical applications of electrocatalytic water splitting (ECWS). Herein, based on a simple quasi chemical vapor deposition (Q-CVD) method, we fabricate a newly Ni 3 S 2 @3-D graphene free-standing electrode for efficient OER applications. The Ni 3 S 2 @3-D graphene integrates the advantageous features of 3-D graphene and Ni 3 S 2 towards OER, such as more interfacial catalytic sites, pore-rich structure, N-doped structure and good electrical conductivity. Benefiting from the favorable features, the Ni 3 S 2 @3-D graphene (especially 900 °C sample) exhibits excellent OER performances in alkaline medium, which includes a low on-set potential (1.53 V), low overpotential of 305 mV at a current density of 10 mA cm−2, and a smaller Tafel slope (50 mV dec−1). This catalyst also shows ultrahigh stability after chronoamperometry response at 10 mA cm−2 for 48 h with 30% increase in the current density. The present work opens a new approach for the one-pot construction of hybrid materials between metal sulfide and graphene to increase the electrocatalytic activity of non-noble metal OER catalysts. • A 3D-GNs@Ni 3 S 2 free-standing electrode has been synthesized by a one-pot Q-CVD technique. • The electrode exhibits remarkable catalytic performance and stability toward OER. • It shows a low on-set potential of 1.53 V, low overpotential of 305 mV at a current density of 10 mA cm−2. • The enhancement effect of graphene acts as dominant role for the high performance and stability. [ABSTRACT FROM AUTHOR]

On account of its low cost, non‐toxicity and high theoretical capacity, ZnS has been considered as one of the most potential anode materials for the following generation lithium‐ion batteries. However, the shortcomings that ZnS shows, such as low conductivity and large volume changes, make its wide application difficult. Herein, we combined ZnS with metal‐organic framework material (ZIF‐8) to form a carbon layer on the surface of nitrogen‐doped zinc sulfide, and obtained a new material ZnS@NC with a specific surface area of 191 m2 g−1. The results show that the reversible specific capacity of the composite is 853 mAh g−1 when the current is 500 mAg−1, which is caused by the increase of specific capacity with nitrogen doping and the effective adjustment of the volume of the carbon layer coated on the periphery of the ZnS particles during charging and discharging process. Promisingly, the performance of ZnS@NC composite is far superior to that of the bare ZnS. [ABSTRACT FROM AUTHOR]

• We fabricated highly transparent MS 2 @N-doped C films as counter electrode in bifacial CdS/CdSe QDSSCs without tedious post-treatment procedures. • The bifacial CdS/CdSe QDSSCs combines the advantages of light color polysulfide solutions and the transparent MS 2 @N-doped C film. • The MS 2 @N-doped C films exhibited superior front and reverse power conversion efficiencies of 4.57% and 3.98% for the NiS 2 @N-doped C film and 3.18% and 2.63% for the FeS 2 @N-doped C film. Semiconductors are widely used as counter electrodes in quantum dot-sensitized solar cells. However, many counter electrode materials have poor conductivity and require tedious post-treatment procedures. Here, our groups develop a highly transparent MS 2 @N-doped C film materials (M = Ni, Fe) derived from layer-by-layer self-assembly of a M-TCPP film as a counter electrode in bifacial CdS/CdSe quantum dot-sensitized solar cells. Devices based on the MS 2 @N-doped C films exhibited higher respective front- and reverse-side power conversion efficiencies (i.e., 4.57% and 3.98% for the NiS 2 @N-doped C film and 3.18% and 2.63% for the FeS 2 @N-doped C film) than those of Pt-based devices (2.39% and 1.74%). We attribute the outstanding catalytic activity and excellent stability of the MS 2 @N-doped C film materials to the homogeneous sulfides within the transparent nitrogen-doped C film, as confirmed by electrochemical analyses, including cycle voltammetry, impedance spectroscopy and Tafel-polarization measurements. [ABSTRACT FROM AUTHOR]

lithium–selenium (Li–Se) batteries are recognized as an attractive candidate for energy storage owing to its high volumetric capacity (3253 mA h cm−3). However, the sluggish electrochemical redox reaction and the accompanying enormous volume fluctuation greatly impede the application of Li–Se batteries. Herein, a catalyst of nickel disulfide (NiS 2) nanoparticles decorated hierarchical porous carbon (HPC) has been fabricated and applied as the cathode for Li-Se batteries. The porous structure offers large amount of viod to buffer the volume change during charge/discharge. At the same time, the NiS 2 nanoparticles exhibit strong adsorption capabilities towards lithium polyselenides and aslo promote the conversion of these intermediates. As a consequence, the NiS 2 -HPC cathode delivers a superior rate capacity (569 mAh g−1 at 0.5 C and 549 mAh g−1 at 1 C) and good cycling stability (289 mAh g−1 after 1000 cycles at 2 C with a Coulombic efficiency of ∼100%). This work demonstrates the viability of employing metal sulfide-anchored porous carbon materials for high-performance lithium-selenium batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

• The development and synthesis of a nanocomposite material containing cadmium sulfide (CdS). • To understand the physical, chemical, and structural features of the CdS-based nanocomposite. • To check the electrochemical behavior of a CdS-based nanocomposite. • The comparative behavior of the different metals sulfide composites. Nanocomposites of CdS/Ag 2 S, CdS/PbS, CdS/CuS, CdS/ZnS, and CdS/MnS were synthesized by a soft template method using emulsion containing water and oil. The synthesized metal sulfides were characterized with UV/vis and FTIR spectroscopy in term of spectral properties which suggested the formation of the desired compounds. Morphology and structural features were determined with the help of SEM and XRD, which depicted the irregular and cluster shapes of the compounds. The cyclic voltammetry described that synthesized compounds have electrochemical properties and have ability to be used as energy storage devices. It was concluded from the results that AAD-5 has depicted 929 mF/g specific capacitance while AAD-2 showed minimum result (6.92 mF/g). Tauc's plot were made to check the optical properties of the compounds and it showed good optical and electrochemical properties. [Display omitted] [ABSTRACT FROM AUTHOR]

The sensitivity of molybdenum (Mo) stable isotopes to redox changes enables innovative geochemical means of tracing the evolution of medium- to high-temperature magmatic hydrothermal processes. However, the Mo isotope geochemical behaviors and fractionation mechanisms in magmatic-hydrothermal systems are still unclear. This study performed high-precision Mo isotope research on well-characterized hydrothermal metal sulfides (pyrite, chalcopyrite, molybdenite and pyrrhotite) from different metallogenic stages and the ore-forming porphyries and surrounding rocks from the giant Pulang porphyry copper deposit in Yunnan, Southwest China, to better understand Mo isotope behaviors in magmatic hydrothermal systems. The results show that compared to the high-temperature magmatic system with homogeneous Mo concentrations (1.44 ppm to 11.3 ppm) and δ98Mo values (−0.41‰ ± 0.05 to −0.08‰ ± 0.03), medium- to high-temperature hydrothermal stage molybdenite displays slightly lighter δ98Mo values (−0.90‰ ± 0.04 to 0.08‰ ± 0.04), and pyrite, chalcopyrite and pyrrhotite, which have low Mo concentrations (0.13 ppm to 28.5 ppm), feature significant δ98Mo variations from −0.34 ± 0.04‰ to 3.01 ± 0.03‰. The absence of fractionated but low δ98Mo values in the magmatic system, combined with the lack of any correlation between the δ98Mo and geochemical index values (e.g., Co/Ni value) of the metal sulfides, implies that the Mo isotope signatures of sulfides in the hydrothermal stage were not inherited from component signatures of the magmatic phase or contamination of surrounding rocks. Our study proposes that heterogeneous partitioning and transportation of heavy/light Mo isotopes into progressively precipitated metal sulfides as a result of changes in the redox-driven metallogenic setting and differential geochemical behaviors of Mo species contribute to the observed δ98Mo variations and that the heavier and strongly variable Mo isotopic signatures correspond to the dominant metallogenic stage of the deposit. Such fractionation may be explained by the Rayleigh fractionation model, whereby 95Mo is preferentially partitioned into isotopically light molybdenite, and the subsequent precipitation of pyrite, chalcopyrite and pyrrhotite from the residual 98Mo-rich ore-forming fluids manifests heavier isotopic compositions. We therefore highlight that the Mo isotopes of metal sulfides provide valuable insights into the precipitation of metal-rich fluids, the identification of favorable mineralization zones, and the ability to trace the evolution of sophisticated magmatic-hydrothermal systems. • Heterogeneous Mo isotope fractionation occurs in magmatic hydrothermal systems. • The Mo isotope variations in metal sulfides possibly reflect Rayleigh fractionation. • The Mo isotope of metal sulfides can trace the evolution of hydrothermal fluids. [ABSTRACT FROM AUTHOR]

[Display omitted] • The larger surface area offers by the SnO 2 microrod. • Doping of sulfur atom creates the heterointerface with enhancing active surface area. • Synergistic effect of S-SnO 2 , S-hBN promotes the electrochemical sensing performance. • The higher sensitivity of S-SnO 2 /S-hBN helps to achieve lower detection limit. • The real sample performance of S-SnO 2 /S-hBN results acceptable recovery rate. Here we demonstrated the sulfur atoms induced an electronic structure modulation of SnO 2 and its synergism with hexagonal boron nitride (hBN) by simple one-step vulcanization process. Thus, S-SnO 2 /S-hBN exhibits extraordinary catalyst material for the electrochemical detection of a toxic insecticide bendiocarb (BDC). The introduction of sulfur atoms to SnO 2 and hBN results an in situ dynamic electronic structure transition, further facilitate the interactions of target with the catalyst structure. Detailed investigation of S-SnO 2 /S-hBN indicates the role of sulfur atoms as an electron acceptor to facilitate electron transfer to SnO 2 /hBN for the electrochemical process. The remarkable interfacial active site in S-SnO 2 /S-hBN provides the lowest limit of detection of 0.285 µM and the best sensitivity of 0.023 µA µM−1 cm−2 under the wide range addition of BDC i.e. 0.02–150.02 µM. Meanwhile, it has proven the top-notch selectivity of BDC even at a higher concentration level of interfering molecules present. This work also satisfies the requirements of commercializing by an appreciable recovery in real-time analysis of food samples with accurate reproducibility and considerable stability shown for electrochemical detection of BDC. [ABSTRACT FROM AUTHOR]

• Metal sulfide gas sensors operated at low temperatures compared to metal oxides. • Low-cost synthesis of metal sulfides is possible using low-cost materials. • PbS, Cu x S, CdS, Ag 2 S, and WS 2 sense ammonia at room temperature. • SnS 2 detects NO 2 at room temperature. • PbS, Cu x S, and Ag 2 S are promising gas-sensing metal sulfides among others. Toxic gases like hydrogen sulfide (H 2 S), ammonia (NH 3), nitrogen dioxide (NO 2), and VOCs like benzene, toluene, xylene, acetone, ethanol, and methanol are emitted from industries due to storage or as byproducts. They create health hazards for humans by inhalation of these gases. Monitoring of the concentration of different gases or VOCs is needed to control the air quality of the surrounding environment. Therefore, sensing these harmful gases or VOCs at a low level of concentration is the primary requirement for using sensors to maintain the air quality. Metal oxide gas sensors are immensely used for these types of applications. But fundamentally, these sensors are suffering from high operating temperatures, stability problems, etc. Recently metal sulfide (MS) based sensors have earned much attention to avoid these problems for sensing toxic gases and VOCs. Lots of experiments have been performed on various types of metal sulfides like lead sulfide (PbS), copper sulfide (Cu x S), cadmium sulfide (CdS), tin (IV) sulfide (SnS 2), zinc sulfide (ZnS), tungsten disulfide (WS 2) and molybdenum disulfide (MoS 2) for preparing gas sensors. The present article aims to review the recent developments in the synthesis of metal sulfide for gas sensors followed by gas sensing mechanisms. Sensitivity, response time and recovery time of these sensors have also been reviewed to evaluate the sensing performances toward toxic gases. Realizing the better metal sulfides for gas sensing applications with better sensing performances among the reported metal sulfides, the future scopes of research are also elucidated in this review. [ABSTRACT FROM AUTHOR]

Heavy metals pollution of aqueous solutions generates considerable concerns as they adversely impact the environment and health of humans. Among the remediation technologies, adsorption with metal sulfide nanomaterials has proven to be a promising strategy due to their cost-effective, environmentally friendly, surface modulational, and amenable properties. Their excellent adsorption characteristics are attributed to the inherently exposed sulfur atoms that interact with heavy metals through various processes. This work presents a comprehensive overview of the sequestration of heavy metals from water using metal sulfide nanomaterials. The common methods of synthesis, the structures, and the supports for metal sulfide nano-adsorbents are accentuated. The adsorption mechanisms and governing conditions and parameters are stressed. Practical heavy metal remediation application in aqueous media using metal sulfide nanomaterials is highlighted, and the existing research gaps are underscored.

Constructing heterojunction has attracted widespread concerns in photocatalysis research. BiOBr/Bi2S3/CdS composite material with a sea urchin shape was directly obtained by first synthesizing BiOBr microspheres. The morphology, structure and composition of the composite material were characterized by XRD, EDX, SEM and XPS. Dye degradation experiments showed that 83.3% of methylene blue removal was achieved after 2 h of visible light irradiation. The reaction rate under optimal conditions was 0.014 min−1 and the photocatalytic degradation process follows a pseudo-first-order kinetic model. Based on the EPR test results, the main active species involved in the reaction were •O2− and h+. The conduction band and valence band edge potential calculations confirmed the key role of CdS in the production of •O2−.