Search

The cadmium manganese sulfide, despite being recognized as a highly efficient photocatalytic semiconductor for hydrogen evolution, faces significant challenges in terms of charge recombination when used solely as a catalyst for photocatalytic hydrogen production. The construction of heterojunction photocatalysts is regarded as one of the effective strategies to enhance the efficiency of photocatalytic hydrogen production. In this work, Zn-doped CdSe was adopted to enhance the photocatalytic active sites of the twinned Mn 0.65 Cd 0.35 S. As results, the photocatalytic hydrogen evolution of Zn–CdSe-1/T-MCS-40 can reach approximately 47447.15 μmol g−1 after 5 h, representing a 15 times increase compared to Mn 0.65 Cd 0.35 S. Besides, the hydrogen evolution rate shows almost no significant attenuation after four consecutive cycles (20 h). The significant achievement can be largely attributed to the successful construction of an S-scheme heterojunction of Zn – CdSe-1/T-MCS-40, which effectively minimized the charge transfer distance and suppressed the recombination of photo-generated electron-hole pairs. Additionally, the incorporation of Zn-doped CdSe significantly expands the response range to visible light, thereby providing a conceptual framework for advancing the design of solar-to-chemical energy conversion and effectively guiding the fabrication of metal sulfide-based photocatalytic heterojunctions. • Zn doping broadens the light absorption range of CdSe. • Zn–CdSe is coupled with T-MCS to form the S-scheme heterojunction. • The photocatalytic rate of Zn–CdSe-1/T-MCS-40 exhibits a 15 enhancement compared to Mn 0.65 Cd 0.35 S. • The separation of photogenerated carrier is accelerated by the construction of S-scheme heterojunction. [ABSTRACT FROM AUTHOR]

As the frequency range of electronic devices gradually expands, exploring frequency insensitive electromagnetic wave adsorption (EWA) materials that can achieve effective absorption in all bands has aroused great interest. A series of Fe1 − xS@C composite materials with three-dimensional conductive networks were successfully prepared in this work. In the preparation process, poly (aryl ether sulfone) with branched carboxylic (PAES-C) was selected as the skeleton and Fe3+ ions were introduced via chemical adsorption. The main purpose of this work was to develop array porous composite materials with good EWA property. The work proposed a novel controllable method for preparing metal sulfides to explore the electromagnetic wave absorption. This routine was also developed to prepare other MxS@C composites (M = Fe, Cu, Mn). Compared to MnxS@C and CuxS@C composites, the RLmin value of Fe1 − xS@C-4 was − 40.6 dB at 13.52 GHz, and at a thickness of 1.5 mm the effective bandwidth reached 3.12 GHz. Furthermore, its effective absorption band covered Ku, X, and C radar bands at different thicknesses. Highlights: •MxS@C composites (M = Fe, Cu, Mn) are prepared for electromagnetic wave absorption. •A new research method for the synthesis of metal sulfides. •The RLmin of Fe1 − xS@C-4 is -40.6 dB, and the effective bandwidth of 3.12 GHz at 1.5 mm. •The absorption band of Fe1 − xS@C composites covered Ku, X, and C radar bands at different thicknesses. [ABSTRACT FROM AUTHOR]

Heterojunction engineering has been deemed one of the most promising strategies for promoting charge separation and improving solar‐to‐chemicals efficiency. Howbeit, constructing well‐defined nanoheterojunction with superior photocatalytic activity for H2O2 generation and a clear reaction mechanism remains a formidable challenge. Herein, an in situ vulcanization way to synthesize an intriguing 2D/1D Bi3TiNbO9/Bi2S3 heterojunction by growing Bi2S3 nanorods on Bi3TiNbO9 microsheet is used for the first time, where an S‐scheme charge transfer mechanism is formed that facilitates the spatial separation of charge carriers. Moreover, the in situ grown Bi2S3 on Bi3TiNbO9 can optimize the interfacial electronic structure and the reaction energy barriers. As a result, the H2O2 yield rate for Bi3TiNbO9/Bi2S3 can reach 810(2) µmol g−1 h−1 without any sacrificial agents and cocatalysts, ≈6.18 and ≈18.0 times of pristine Bi3TiNbO9 and Bi2S3, respectively. Importantly, the heterojunction unveiled unprecedented stability, remaining ≈95.46(2)% of the initial one after 13 continuous cycles. This work highlights an innovative in situ vulcanization strategy to engineer oxide perovskite/metal sulfide nanocomposite catalysts for artificial photosynthesis of H2O2, opening new opportunities for achieving highly efficient photocatalyst systems. [ABSTRACT FROM AUTHOR]

The electrocatalytic nitrate reduction reaction (NO3−RR) presents a promising pathway for achieving both ammonia (NH3) electrosynthesis and water pollutant removal simultaneously. Among various electrocatalysts explored, 2D materials have emerged as promising candidates due to their ability to regulate electronic states and active sites through doping. However, the impact of doping effects in 2D materials on the mechanism of NO3−RR remains relatively unexplored. Here, Ni‐doped MoS2 (Ni‐MoS2) nanosheets are investigated as a model system, demonstrating enhanced NO3−RR performance compared to undoped counterparts. By controlling the doping concentration, the Ni‐MoS2 nanosheets achieve a remarkable faradic efficiency (FE) of 92.3% for NH3 at −0.3 VRHE with excellent stability. The mechanistic studies reveal that the elevation of the NO3−RR performances originates from the generation of more active hydrogen and the acceleration of the reaction from nitrite (NO2−) to NH3 facilitated by Ni doping. Combining the experimental observations and theoretical calculations it is revealed that the appropriate Ni doping level in MoS2 can enhance *NO3 adsorption strength, thereby facilitating subsequent electrocatalytic steps. Together with the demonstration of Zn−NO3− and Zn−NO2− battery devices, the work provides new insights into the design and regulation of the active sites in 2D material catalysts for efficient NO3−RR. [ABSTRACT FROM AUTHOR]

The electrochemical NOx reduction reactions, involving nitrate and nitrite reduction reactions (NO3−RR and NO2−RR), have emerged as promising approaches for both NO3− and NO2− removal, and ammonium (NH3) synthesis under ambient conditions. However, the incorporation and stabilization of sulfur dopants in the catalysts for efficient NOx reduction are rarely explored, leading to an unclear effect of sulfur on the NOx reduction mechanism. Herein, sulfur‐doped Cu2O (S‐Cu2O) nanoneedle arrays via in situ electrochemical treatment are synthesized. The S‐Cu2O catalyst possesses excellent durability and selectivity for NH3 over a wide range of potentials in NO3−RR, attaining a maximum NH3 Faradaic efficiency of 94% at −0.6 VRHE and a maximum NH3 yield as high as 1.06 mmol h−1 cm−2. In NO3−RR, the sulfur dopant can accelerate the step from NO2− to NH3, contributing superior performance in NO2−RR and assembled Zn−NO2− battery device. Density functional theory (DFT) calculations reveal that the presence of sulfur can enhance the initial step of *NO3 adsorption, lower the reaction barriers for the formation of *NHO intermediate, and activate the H2O dissociation process. The work sheds light on the role of sulfur in enhancing electrocatalytic performance and provides a unique perspective for understanding the NOx reduction mechanism. [ABSTRACT FROM AUTHOR]

To explore advanced oxidation catalysts, peroxymonosulfate (PMS) activation by Co-Ni-Mo/carbon nanotube (CNT) composite catalysts was investigated. A compound of NiCo2S4, MoS2, and CNTs was successfully prepared using a simple one-pot hydrothermal method. The results revealed that the activation of PMS by Co-Ni-Mo/CNT yielded an exceptional Rhodamine B decolorization efficiency of 99% within 20 min for the Rhodamine B solution. The degradation rate of Co-Ni-Mo/CNT was 4.5 times higher than that of Ni-Mo/CNT or Co-Mo/CNT, and 1.9 times as much than that of Co-Ni/CNT. Additionally, radical quenching experiments revealed that the principal active groups were 1O2, surface-bound SO4•−, and •OH radicals. Furthermore, the catalyst exhibited low metal ion leaching and favorable stability. Mechanism studies revealed that Mo4+ on the surface of MoS2 participated in the oxidation of PMS and the transformation of Co3+/Co2+ and Ni3+/Ni2+. The synergism between MoS2 and NiCo2S4 reduces the charge transfer resistance between the catalyst and solution interface, thus accelerating the reaction rate. Interconnected structures composed of metal sulfides and CNTs can also enhance the electron transfer process and afford sufficient active reaction sites. Our work provides a further understanding of the design of multi-metal sulfides for wastewater treatment. [ABSTRACT FROM AUTHOR]

A novel Pd-doped In 2 S 3 photocatalyst with rich S vacancies has been fabricated through a one-pot synthesis process. Experimental characterizations and DFT calculations reveal that the synergistic effect of Pd doping and S vacancies endows In 2 S 3 with a favorable band structure and an effective charge transfer channel, thereby leading to a significant enhancement in photocatalytic H 2 evolution. [Display omitted] In this study, a simple one-pot synthesis process is employed to introduce Pd dopant and abundant S vacancies into In 2 S 3 nanosheets. The optimized Pd-doped In 2 S 3 photocatalyst, with abundant S vacancies, demonstrates a significant enhancement in photocatalytic hydrogen evolution. The joint modification of Pd doping and rich S vacancies on the band structure of In 2 S 3 result in an improvement in both the light absorption capacity and proton reduction ability. It is worth noting that photogenerated electrons enriched by S vacancies can rapidly migrate to adjacent Pd atoms through an efficient transfer path constructed by Pd-S bond, effectively suppressing the charge recombination. Consequently, the dual-defective In 2 S 3 shows an efficient photocatalytic H 2 production rate of 58.4 ± 2.0 μmol·h−1. Additionally, further work has been conducted on other ternary metal sulfide, ZnIn 2 S 4. Our findings provide a new insight into the development of highly efficient photocatalysts through synergistic defect engineering. [ABSTRACT FROM AUTHOR]

Developing low-cost, high-efficiency electrocatalysts is critically important for efficient hydrogen production. In this study, a novel electrocatalyst, Co–CuS/MoS 2 nanocomposite, was successfully synthesized via ion exchange on carbon cloth using Evans-Showell type polyoxometalate (NH 4) 6 [Co 2 Mo 10 O 38 H 4 ]·11H 2 O (Co2Mo10) as a precursor and thiourea in a hydrothermal reaction. The optimized Co–CuS/MoS 2 exhibited outstanding hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities, with overpotentials of 90 mV and 270 mV at a current density of 10 mA cm−2, respectively, and demonstrated long-term stability in alkaline electrolytes. The superior performance of this catalyst is attributed to the high charge transfer rates between MoS 2 and CuS, abundant heterostructure interfaces, and efficient diffusion channels. This study provides a new design strategy for exploring efficient bifunctional electrocatalysts. [Display omitted] • Using ion exchange method, a novel MoS2-based nanocomposite material is synthesized on carbon cloth. • Incorporating Cu into the polyoxometalate structure brings it closer to the active centers of MoS 2. • The catalyst demonstrates superior stability and tolerance in water electrolysis, surpassing 20% Pt/C catalyst. [ABSTRACT FROM AUTHOR]

Heterogeneous catalysis promises to accelerate sulfur-involved conversion reactions in lithium-sulfur batteries. Solid-state Li2S dissociation remains as the rate-limiting step because of the weakly matched solid-solid electrocatalysis interfaces. We propose an electrochemically molecular-imprinting strategy to have a metal sulfide (MS) catalyst with imprinted defects in positions from which the pre-implanted Li2S has been electrochemically removed. Such tailor-made defects enable the catalyst to bind exclusively to Li atoms in Li2S reactant and elongate the Li–S bond, thus decreasing the reaction energy barrier during charging. The imprinted Ni3S2 catalyst shows the best activity due to the highest defect concentration among the MS catalysts examined. The Li2S oxidation potential is substantially reduced to 2.34 V from 2.96 V for the counterpart free of imprinted vacancies, and an Ah-level pouch cell is realized with excellent cycling performance. With a lean electrolyte/sulfur ratio of 1.80 μL mgS–1, the cell achieves a benchmarkedly high energy density beyond 500 Wh kg–1. [ABSTRACT FROM AUTHOR]

This study focuses on exploring the indication and importance of selenium (Se) and tellurium (Te) in distinguishing different genetic types of ore deposits. Traditional views suggest that dispersed elements are unable to form independent deposits, but are hosted within deposits of other elements as associated elements. Based on this, the study collected trace elemental data of pyrite, sphalerite, and chalcopyrite in various types of Se-Te bearing deposits. The optimal end-elements for distinguishing different genetic type deposits were recognized by principal component analysis (PCA) and the silhouette coefficient method, and discriminant diagrams were drawn. However, support vector machine (SVM) calculation of the decision boundary shows low accuracy, revealing the limitations in binary discriminant visualization for ore deposit type discrimination. Consequently, two machine learning algorithms, random forest (RF) and SVM, were used to construct ore genetic type classification models on the basis of trace elemental data for the three types of metal sulfides. The results indicate that the RF classification model for pyrite exhibits the best performance, achieving an accuracy of 94.5% and avoiding overfitting errors. In detail, according to the feature importance analysis, Se exhibits higher Shapley Additive Explanations (SHAP) values in volcanogenic massive sulfide (VMS) and epithermal deposits, especially the latter, where Se is the most crucial distinguishing element. By comparison, Te shows a significant contribution to distinguishing Carlin-type deposits. Conversely, in porphyry- and skarn-type deposits, the contributions of Se and Te were relatively lower. In conclusion, the application of machine learning methods provides a novel approach for ore genetic type classification and discrimination research, enabling more accurate identification of ore genetic types and contributing to the exploration and development of mineral resources. [ABSTRACT FROM AUTHOR]

The ternary metal sulfide CoS2:Ni17S18:Al2S3 thin films were created in the presence of diethyldithiocarbamate as a sulfur source, pursued by physical vapour deposition. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV-visible spectrophotometer, and Fourier transform infrared spectroscopy were used to identify and characterize the synthesised substances. The ternary metal sulfide had a mean crystallite size of 37.8 nm on the nanoscale. SEM revealed spherical particles with rounded edges particles. XPS presented Al 2p, Co 2p, Ni 2p and S 2p core level peaks of the elements. The ternary metal sulfide had a band gap energy of 3.49 eV. The phenomenal storage technology potential of the thin film was evaluated using cyclic voltammetry that revealed an astounding supercapacitance of 515 F g−1, demonstrating the material's effectiveness. Voltammetric findings show the cycling stability of the nanoparticle thin film. Moreover, the photocatalytic degradation of contaminants such as methylene blue dye, pesticide zoxamide, and phenol was probed, with such a spectacular degradation rate constant of 4.11 × 10−2 min−1 with 91.5% degradation achieved for pesticide. [ABSTRACT FROM AUTHOR]

The construction of Z‐scheme systems is an efficient strategy to realize water splitting under visible light irradiation. In particular, various photocatalysts can be employed for Z‐scheme systems when a reduced graphene oxide (RGO) is used as an electron mediator. Herein, a simple 1‐step process for the preparation of RGO‐(CoOx/BiVO4) composites is developed. In the developed preparation method, Co ions are oxidized to CoOx by photogenerated holes in BiVO4 accompanied by simultaneous reduction of GO to RGO by photoexcited electrons. The developed preparation method is simpler than a conventional method that contains loading with CoOx by impregnation and subsequent incorporation of RGO by photocatalytic reduction. Z‐schematic water splitting under visible light irradiation proceeds when RGO‐(CoOx/BiVO4) prepared by the 1‐step process is combined with Pt/(CuGa)0.5ZnS2. Moreover, the developed method is also able to be applied to the preparation of RGO‐(FeOx/BiVO4) composites. [ABSTRACT FROM AUTHOR]

Metal sulfide nanoparticles have recently attracted much attention due to their unique physical and functional properties. Metal sulfide nanoparticles used as optoelectronic and biomedical materials in the past decades are promising for making functional nanocomposite films due to their low toxicity and strong antibacterial activity. Recently, copper sulfide and zinc sulfide nanomaterials have been used to produce food packaging films for active packaging. Metal sulfide nanoparticles added as nanofillers are attracting attention in packaging applications due to their excellent potential to improve mechanical, barrier properties, and antibacterial activity. This review covers the fabrication process and important applications of metal sulfide nanoparticles. The development of metal sulfides reinforcing mainly copper sulfide and zinc sulfide nanomaterials as multifunctional nanofillers in bio-based films for active packaging applications has been comprehensively reviewed. As the recognition of metal sulfide nanoparticles as a functional filler increases, the development and application potential of active packaging films using them is expected to increase. [ABSTRACT FROM AUTHOR]

Metal sulfide‐based homojunction photocatalysts are extensively explored with improved photocatalytic performance. However, the construction of metal sulfide‐based S‐scheme homojunction remains a challenge. Herein, the fabrication of 2D CdIn2S4 nanosheets coated 3D CdIn2S4 octahedra (referred to as 2D/3D n‐CIS/o‐CIS) S‐scheme homojunction photocatalyst is reported by simply adjustment of polyvinyl pyrrolidone amount during the solvothermal synthesis. The formation of S‐scheme homojunction within n‐CIS/o‐CIS is systematically investigated via a series of characterizations, which can generate an internal electric field to facilitate the separation and migration of photogenerated electron‐hole pairs. The 2D/3D n‐CIS/o‐CIS composite exhibits significantly improved photocatalytic activity and stability in the selective oxidation of phenylcarbinol (PhCH2OH) to benzaldehyde (PhCHO) when compared to pure n‐CIS and o‐CIS samples under visible light irradiation. It is hoped that this work can contribute novel insights into the development of metal sulfides S‐scheme homojunction photocatalysts for solar energy conversion. [ABSTRACT FROM AUTHOR]

This study reports the preparation of binary metal sulfide heterostructure enclosed in functional carbon layer (termed CoS 2 /SnS 2 @SC) as anodes for PIBs by a synchronous vulcanization process with chemical vapor deposition (CVD), which achieves high electrochemical and kinetic performance and has far-reaching implications for the study of potassium storage devices. [Display omitted] Metallic sulfides are currently considered as ideal anode materials for potassium-ion batteries by virtue of their high specific capacities. However, their low intrinsic electronic conductivity, large volume variation and dissolution of polysulfides in electrochemical reactions hinder their further development toward practical applications. Here, we propose an effective structural design strategy by encapsulating CoS 2 /SnS 2 in sulfur-doped carbon layers, in which internal voids are created to relieve the strain in the CoS 2 /SnS 2 core, while the sulfur-doped carbon layer serves to improve the electron transport and inhibit the dissolution of polysulfides. These features enable the as-designed anode to deliver a high specific capacity (520 mAh/g at 0.1 A/g), a high rate capability (185 mA h g−1 at 10 A/g) and lifespan (0.016 % capacity loss per cycle up to 1500 cycles). Our comprehensive electrochemical characterization reveals that the heterostructure of CoS 2 /SnS 2 not only promotes charge transfer at its interfaces, but also enhances the rate of K+ diffusion. Additionally, potassium-ion capacitors based on this novel anode are able to attain an energy density up to 162 Wh kg−1 and ∼ 96 % capacity retention after 3000 cycles at 10 A/g. The demonstrated design rule combining morphological and structural engineering strategies sheds light on the development of advanced electrodes for high performance potassium-based energy storage devices. [ABSTRACT FROM AUTHOR]

Nanocomposites based on natural biopolymers are attractive materials for preparing high adsorbents to remove different pollutants from water due to their ability, good porosity, high specific surface area, and easy separation. Herein, to explore eco-friendly cellulose biosorbents, we fabricated cellulose-based nanocomposite CL/M@Hg and CL/M@Pb using the grafting of cellulose with malic acid and metal sulfides via a one-pot procedure. The synthesis nanocomposites were characterized using FT-IR, EDS, TGA, XRD, and SEM. Characterization results predicted that the successful preparation of CL/M@Hg and CL/M@Pb. EDS/SEM results confirmed the distribution of metal sulfide nanoparticles on the as-prepared CL/M composites. In addition, methyl green (MG) adsorption using them was studied and the effect of important parameters such as initial pH solution, adsorbents dose, and contact time was investigated and discussed. At optimum conditions, the maximum adsorption capacity of MG dye using CL/M@Hg and CL/M@Pb was found to be 123.27 mg/g (R=88.05 %) and 134.75 mg/g (R=96.25 %), respectively. The adsorption kinetics were described well by the pseudo-second-order (PSO) model rather than the pseudo-first-order (PFO) model. Due to the presence of active sites on the surface of the as-prepared nanocomposites, we proposed that the adsorption mechanism included a lot of electrostatic attractions, n-π stacking, and hydrogen bonding. The as-prepared nanocomposites are recyclable for six cycles without significant loss of their adsorption capacity. Therefore, they have great potential for the remediation of organic dyes from wastewater.

For highly efficient solid-liquid separation after uranium adsorption from acidic wastewater, layered metal sulfide@polymer nanofibers, KMS-1@PVA/PAA, KMS-2@PVA/PAA, and KTS-3@PVA/PAA, were successfully synthesized. The outcomes of batch adsorption experiments revealed that uranium(VI) removal on three nanofibers exhibited dependency on pH and almost no dependency on ionic strength. The membrane separation experiment indicated that the adsorption capacities for KMS-1@PVA/PAA, KMS-2@PVA/PAA, and KTS-3@PVA/PAA were 234.78 mg/g, 254.18 mg/g, and 205.05 mg/g, respectively, ranking competitive position among the reported fiber materials. The determined kinetics, isotherms and thermodynamic parameters proved the layered metal sulfide@polymer nanofiber were prone to adsorb uranium in acidic environment. [ABSTRACT FROM AUTHOR]

Application of nanoparticles (NPs) guides the design of the particle for enhancing specific properties of interest for that particular application. Two-dimensional transition-metal carbides, nitrides, and carbonitrides [also known as MXene nanosheets (NSs)] have attracted interest as an approach for improving the properties of functional materials of NPs. The modification of surface chemistry has frequently been employed to amplify favorable physical and chemical characteristics of MXenes. A straightforward, economical, and remarkably effective technique in this aspect is the implementation of metal sulfide (MS) nanostructures that adhere to MXene NSs through van der Waals interactions. The inherent self-assembly properties of these structures enable simple regulation of the packaging density of the particles. For environmental remediation, properties such as narrow band gap and increased electron and hole transfer make MS/MXene nanocomposites suitable for the degradation and removal of pollutants. For energy applications, the MXene NSs serve as conductive substrates, facilitating fast electron and ion transport, to prevent the aggregation of MS nanostructures. Transition-metal sulfides act as spacers in these designs. In the field of medicine, MS/MXene nanocomposites can be utilized for targeted therapy, for the diagnosis and treatment of cancer, and as antibacterial agents due to their high absorption in the near-infrared region. The present review summarizes the integration of MS/MXene nanocomposites, with a brief discussion of the synthesis and traits of MXenes, along with the progress of various MXene composites, applications of the various NSs, and some of the challenges and future prospects associated with the development of MS/MXene nanocomposites, while highlighting their potential for diverse applications. [ABSTRACT FROM AUTHOR]

The development of cost-effective and highly efficient bifunctional catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media plays a crucial role in advancing renewable energy conversion technologies. In this study, we successfully constructed a three-dimensional (3D) composite on nickel foam (NF) by coupling NiFe-LDH nanosheets with NiCoS nanoparticles decorated NiCo-LDH nanosheets, resulting in a NiCo-LDH@NiCoS@NiFe-LDH hierarchical heterostructure. The resulting composite exhibits abundant heterogeneous interfaces and a well-defined nanosheet array structure, allowing for numerous exposed surface active sites and open channels. The strong synergistic effect among its various components allows the heterogeneous structure to effectively optimize the electronic structures of the metal active sites. Consequently, the NiCo-LDH@NiCoS@NiFe-LDH composite demonstrated remarkable catalytic activity towards OER, achieving current densities of 50 and 100 mA cm−2 at overpotentials as low as 209 and 224 mV, respectively. This result manifests a substantial improvement over recently developed electrocatalysts based on earth-abundant elements. Additionally, the NiCo-LDH@NiCoS@NiFe-LDH composite can efficiently catalyze HER in an alkaline medium, with a low overpotential of 93 mV at 10 mA cm−2 in 1 M KOH solution. Moreover, the electrolytic cell utilizing NiCo-LDH@NiCoS@NiFe-LDH as the electrodes could realize overall water splitting with an ultralow cell voltage of 1.55 V at 10 mA cm−2, and excellent electrochemical stability. These findings underscore the potential for developing high-performance bifunctional electrocatalysts with significant implications for large-scale commercial applications of renewable energy technologies. • A 3D hierarchical heterostructure of NiCo-LDH@NiCoS@NiFe-LDH was constructed on NF. • The composite shows well-defined nanosheet array structure with rich heterointerface. • It delivers an efficient bifunctional electrocatalyst for OER and HER in 1 M KOH. • Overall water splitting requires an ultralow cell voltage of 1.55 V at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Slow hole transfer is one of the important reasons for limited charge separation. This work reports a strategy to construct a p-n heterojunction biomimetic hollow composite (Cu 2-x S@ZGS) by combining Cu 2-x S (composed of Cu 7.2 S 4 and Cu 1.96 S) with Zn 3.74 Ga 1.02 S 5.24 (ZGS) to promote charge space separation and improve the photocatalytic hydrogen production activity of ZGS. Cu 2-x S@ZGS shows significantly enhanced photocatalytic hydrogen production. The hydrogen production rate of 7 %Cu 2-x S@ZGS is 44 and 3 times higher than that of Cu 2-x S and ZGS under simulated sunlight and is 36, 30, and 25 times higher than that of Cu 2 S, Cu 2-x S, and ZGS under visible-light-driven, respectively. The biomimetic hollow structure provides the site of spatial separation for the redox reaction. The Cu 2-x S/ZGS p-n heterojunction promotes the migration of photogenerated holes to the inner Cu 2-x S, where oxidation reactions occur, and it promotes the migration of photogenerated electrons to the outer ZGS, where the proton reduction reaction occurs, improving the spatial separation efficiency of charges. In addition, the Cu vacancies of Cu 2-x S further promote the rapid transfer of h+ and the S vacancies of ZGS expose the active site to enhance hydrophilicity. This study provides design ideas and synthesis guidance for heterojunction catalysts that achieve photogenerated charge spatial separation. [Display omitted] • The biomimetic Cu 2-x S@ZGS hollow composite with p-n heterojunctions was developed. • p-type Cu 2-x S extracts photogenerated holes to improve carrier's transfer. • n-type ZGS with S defects has a larger surface area and hydrophilia. • The p-n heterojunction hollow structure achieves the spatial separation of charges. [ABSTRACT FROM AUTHOR]

Background: Considerable research efforts have been dedicated to comprehensively evaluate the electrochemical and photocatalytic properties of newly synthesized metal sulfides. Aims: This research aims to determine the viability of using metal sulfide, MnS2:Ni9S8:Co3S4 thin film with excellent energy retention capacities and amazing photocatalytic activities. Materials & Methods: Single source precursor method was utilized for the synthesis of metal sulfide. Furthermore, deposition of thin film was performed through physical vapour deposition route. Detailed characterization was done by using UV-visible spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction crystallography and X-ray photoelectron spectroscopy. Electrochemical investigation was done through cyclic and linear sweep voltammetry while competence of the thin film in degrading various environmental pollutants, including crystal violet dye, fuberidazole and phenol, was evaluated by photocatalytic degradation. Results & Discussion: A crystallite size of 47 nm with 86.5% crystallinity was found along with a 3.4 eV bandgap energy. Round-edged cubical structures in the composite were seen. X-ray photoelectron spectroscopy revealed core level peaks of Mn 2p, Ni 2p, Co 2p and S 2p. A specific capacitance of 590 Fg-1 was observed from the electrochemical analysis showing the presence of electroactive sites that allow for effective electrochemical processes. After 60 minutes of exposure to the thin film, phenol showed the slowest rate of degradation, whereas crystal violet and fuberidazole showed significant percentages of deterioration. Conclusion: The findings highlight MnS2:Ni9S8:Co3S4 thin film's adaptability as viable compound for addressing the critical concerns of storing energy, production, and environmental cleanup. These significant findings highlight the versatility of tri-metal sulfide thin films, opening up avenues for further research and technological advancements. [ABSTRACT FROM AUTHOR]

The research was done on the creation and use of bi‐metal sulfide thin film, Nd2S3:Ni9S8. 41 nm‐sized crystallites with 80% crystallinity were found in the material. The evaluated optical characteristics showed a 2.9 eV band gap energy. The presence of Nd3d, S2p, and Ni2p in the created material was confirmed by X‐ray photoelectron spectroscopy. Voltammetry tests were carried out to assess the electrochemical characteristics. With a value of 750 Fg−1, the findings obtained showed remarkable supercapacitive capability. Additionally, a thorough examination was done to learn more about the material's potential as a photocatalyst. Malachite green dye, fuberidazole, and phenol were used as environmental contaminants to test the thin films' photocatalytic degradation effectiveness. The highest degradation was found for fuberidazole with a rate constant of 2.46x10−2 min−1. The results demonstrated the versatility of thin films and their efficacy in degrading these pollutants, highlighting their potential for environmental remediation applications. [ABSTRACT FROM AUTHOR]

The Co-based organic skeleton was combined with graphene oxide (GO) as a precursor, Ni2+ hydrolysis etching was introduced, and finally, NiCo-LDH/GO was obtained. The final composite electrode material NiCo2S4/rGO was obtained by high-temperature vulcanization. The introduction of MOFs and rGO significantly increased the specific surface area of the material and made it have excellent electrochemical properties. The specific capacitance of the composite NiCo2S4/20rGO reaches an astonishing 272.5 mAh g−1 when the current density is 1 A g−1. In addition, at a large current of 10 A g−1, the specific capacitance of the material can also reach 139.5 mAh g−1, and after a long cycle of 5000 cycles at such a current density, the capacity remains at the original 73.2%. With NiCo2S4/20rGO electrode material as the positive electrode and activated carbon as the negative electrode, the hybrid supercapacitor is assembled. At an energy density of 56.9 Wh kg−1, its power density reaches an excellent 799 W kg−1, and it still has a capacity retention rate of 74% at a current density of 10 A g−1. The excellent properties of composites demonstrated in this work open up new possibilities for high-quality energy storage devices. [ABSTRACT FROM AUTHOR]

Abstract Metal sulfide‐based homojunction photocatalysts are extensively explored with improved photocatalytic performance. However, the construction of metal sulfide‐based S‐scheme homojunction remains a challenge. Herein, the fabrication of 2D CdIn2S4 nanosheets coated 3D CdIn2S4 octahedra (referred to as 2D/3D n‐CIS/o‐CIS) S‐scheme homojunction photocatalyst is reported by simply adjustment of polyvinyl pyrrolidone amount during the solvothermal synthesis. The formation of S‐scheme homojunction within n‐CIS/o‐CIS is systematically investigated via a series of characterizations, which can generate an internal electric field to facilitate the separation and migration of photogenerated electron‐hole pairs. The 2D/3D n‐CIS/o‐CIS composite exhibits significantly improved photocatalytic activity and stability in the selective oxidation of phenylcarbinol (PhCH2OH) to benzaldehyde (PhCHO) when compared to pure n‐CIS and o‐CIS samples under visible light irradiation. It is hoped that this work can contribute novel insights into the development of metal sulfides S‐scheme homojunction photocatalysts for solar energy conversion.

Using the simple Chemical Bath Deposition (CBD) method, Cu-doped thin films of zinc sulfide (ZnS) were deposited on glass substrates in a concentration range of 0.05-0.1% Cu. These films were made to be used as a buffer or window layer in solar cells. Different deposition conditions were investigated to find the optimal growth conditions; after that, the conditions were deployed to deposit the required films. XRD graphs confirmed a hexagonal structure, and SEM images indicated that the incorporation of Cu stabilises small grain growth in the films. The appearance of the sample surface was dense, with an ordered granular shape, and free of any cracks. The optical and surface properties of the prepared films have been analysed using stateof-the-art instruments. The effect of pH on such properties has also been investigated. The transmittances of the films were about 20–85%, and the incident wavelength range was 300– 1100 nm. The transmission line shows a sharply increasing tendency. After that, it increases slowly and goes to a stable state above 400 nm. A film of pH 10.0 showed a high transmission coefficient (85%). Also, the absorbance of the ZnS thin films rapidly decreases up to 360 nm. After that, it decreases slowly and becomes stable above 400 nm. The band gap is in the range of 3.58–3.62 eV, which indicates that it absorbed the UV portion of the electromagnetic wave and could be used as the UV filter.

It remains challenging to design alkaline hydrogen evolution reaction (HER) electrocatalyst able to stably operate at ampere-level current density. In this work, we successfully synthesized heterostructured Ni 3 S 2 /Cr 2 S 3 nanosheets on nickel foam (Ni 3 S 2 /Cr 2 S 3 /NF) for high current HER electrocatalysis in alkaline media. As-prepared Ni 3 S 2 /Cr 2 S 3 /NF reaches 0.5 and 1.0 A cm−2 currents at 230 and 333 mV overpotential, respectively. After 50 h test at 0.5 A cm−2, the potential of Ni 3 S 2 /Cr 2 S 3 /NF remained almost unchanged. This impressive HER performance stems from its unique hybridization nature enabled hydrogen spillover, in which Cr 2 S 3 efficiently catalyzes the Volmer step, i.e., water dissociation to generate hydrogen, and the latter further transports to neighboring Ni 3 S 2 via spillover to facilitate the molecular hydrogen formation. This work provides a feasible strategy to synthesize efficient and durable HER catalysts for ampere-level water splitting. • Heterostructured bimetallic sulfide Ni 3 S 2 /Cr 2 S 3 was prepared by a one-step hydrothermal method. • The catalyst exhibits remarkable HER activity under alkaline conditions. • The hydrogen spillover provides an effective way to accelerate multi-step HER through relay catalysis. • The catalyst requires low overpotentials of 333 mV to reach 1000 mA cm−2 with long-term durability. [ABSTRACT FROM AUTHOR]

Zn-BTC (H3BTC refers to 1, 3, 5-benzoic acid) MOF was used as a self-template and a zinc source to prepare ZnS/NiS2 with a layered heterogeneous structure as a promising electrode material using cation exchange and solid-phase vulcanization processes. The synergistic effect of the two metal sulfides enhances the application of ZnS/NiS2. And the high specific surface area and abundant active sites further promote the mass/charge transfer and redox reaction kinetics. In the three-electrode system, the specific capacitance was as high as 1547 F/g at a current density of 1 A/g, along with satisfactory rate capability (1214 F/g at 6 A/g) and cycling performance. Coupled with activated carbon (AC), the prepared hybrid device (ZnS/NiS2 as the positive electrode and AC as the negative electrode) (ZnS/NiS2/AC) can be operated under a potential window of 1.6 V and provides a high energy density of 26.3 Wh/kg at a power density of 794 W/kg. Notably, the assembled ZnS/NiS2//AC showed little capacity degradation after 5000 charge/discharge cycles. [ABSTRACT FROM AUTHOR]

This research endeavors to comprehensively expound upon the effective production and analysis of thin films composed of ZrS3:MnS2:Ni9S8 ternary metal sulfides, achieved through the implementation of diethyl dithiocarbamate as a sulfur source via the process of physical vapor deposition. Through the utilization of X-ray diffraction analysis, the discerned crystallite size of the thin films was determined to be 27 nm. Insights into the optical characteristics manifested a bandgap energy measuring 2.6 eV. Zr 3d, S 2p, Ni 2p, and Mn 2p core levels were found in the material through the X-ray photoelectron spectroscopy. The electrochemical features of the substance were analyzed through cyclic voltammetry, displaying noteworthy specific capacitance of 532 Fg−1. Furthermore, the thin film revealed commendable cycle stability, thus establishing them as a highly promising contender for various energy storage applications. An in-depth investigation was conducted to explore the photocatalytic prowess of the material, specifically its ability to effectively degrade a diverse range of environmental pollutants. The results exhibited good degradation rate constants 1.43 × 10–2, 2.25 × 10–2, and 2.42 × 10–2 min−1, for crystal violet dye, pesticide, and phenol, respectively, with the highest degradation for phenol being 76.5%. These findings serve as compelling evidence of the extensive technological prospects offered by ternary metal sulfide thin films, extending beyond their role in energy storage to encompass advanced applications such as photodegradation and beyond. [ABSTRACT FROM AUTHOR]

The detection and quantification of metal sulfides in host rocks by electrical measurements have been priorities for field and laboratory studies, motivated by mineral prospecting and fundamental interest in the mantle structure or core/mantle differentiation, among other reasons. Here, we reanalyze electrical data for a dunite host with added FeS or Fe-S-Ni (Saxena et al. 2021), and report additional experimental runs along with electron microprobe analyses. The applied pressure was 2 GPa; impedance spectra were acquired while annealing at 1023 K (below the metal-sulfide solidus), and while varying temperature from 570 to 1650 K. Addition of 6.5 or 18 vol% FeS strongly enhances conductivity of the bulk sample compared with that of the dunite host, though values are 100–100 000 times less than those of pure FeS. These results indicate that most metal sulfide content is not part of a viable conductive path, even for the 18 vol% quantity. Nevertheless, the relatively high conductivity and weak temperature dependence of the 18 vol% sample reveal that contiguous paths of solid or molten FeS span the electrodes. The sample with 6.5 vol% sulfide also exceeds the percolation threshold for temperatures as low as ~100 K below the eutectic melting point, likely because FeS softens. Conductivity is nearly unchanged upon crossing the eutectic temperature, however a decline over 1400–1500 K reveals that the 6.5 vol% molten FeS forms a fragile electrical network in dunite. Samples with Fe50S40Ni10 or Fe40S40Ni20 (at%) are less conductive than pure dunite at temperatures below ~1450 K. This surprising result, likely caused by a reducing influence of Fe or Ni metal, does not support the use of FeS as an analog for compositions with nickel or excess metal. Our findings suggest that probing the electrical network of metal sulfides as solids complements other studies focused on connectivity of molten metal sulfides. [ABSTRACT FROM AUTHOR]

Here a caterpillar-like three-dimensional (3D) FeS 2 @C@SnS 2 hierarchical heterostructure with heteronuclear bimetallic active sites and protective/conductive carbon layer was well-engineered for enhancing the peroxidase-like behavior significantly. By in-situ growth of SnS 2 nanosheets over MIL-88A@PDA derived FeS 2 @C, it achieves abundant spatially separated FeS 2 and SnS 2 reactive sites to perform their catalyzing action maximumly, and create heterophase interfaces between different building blocks to accelerate ion conduction/electron transport, while the existence of carbon layer can preserve the integrality of 3D configuration well and suppress the structural deformation when participating electrocatalytic reaction. As a sensing application, such a FeS 2 @C@SnS 2 sensor delivers sufficient electrocatalytic locations, fast electronic kinetics, and structural robustness to capture selectively and measure efficiently DA molecule, and produce appealing electrochemical performance that are especially prominent for its high sensitivity (382.2 μA μM−1 cm−2) and ultra-low LOD (0.116 nM). Additionally, the powerful sensitivity and stability characteristics enable it to check DA in human serum efficiently and obtain satisfactory results. Undoubtedly, this work uncovers new insights for engineering heterostructure composites and further expanding their applications in complex biosystems. [ABSTRACT FROM AUTHOR]

To explore advanced oxidation catalysts, peroxymonosulfate (PMS) activation by Co-Ni-Mo/carbon nanotube (CNT) composite catalysts was investigated. A compound of NiCo2S4, MoS2, and CNTs was successfully prepared using a simple one-pot hydrothermal method. The results revealed that the activation of PMS by Co-Ni-Mo/CNT yielded an exceptional Rhodamine B decolorization efficiency of 99% within 20 min for the Rhodamine B solution. The degradation rate of Co-Ni-Mo/CNT was 4.5 times higher than that of Ni-Mo/CNT or Co-Mo/CNT, and 1.9 times as much than that of Co-Ni/CNT. Additionally, radical quenching experiments revealed that the principal active groups were 1O2, surface-bound SO4•−, and •OH radicals. Furthermore, the catalyst exhibited low metal ion leaching and favorable stability. Mechanism studies revealed that Mo4+ on the surface of MoS2 participated in the oxidation of PMS and the transformation of Co3+/Co2+ and Ni3+/Ni2+. The synergism between MoS2 and NiCo2S4 reduces the charge transfer resistance between the catalyst and solution interface, thus accelerating the reaction rate. Interconnected structures composed of metal sulfides and CNTs can also enhance the electron transfer process and afford sufficient active reaction sites. Our work provides a further understanding of the design of multi-metal sulfides for wastewater treatment.

This study focuses on exploring the indication and importance of selenium (Se) and tellurium (Te) in distinguishing different genetic types of ore deposits. Traditional views suggest that dispersed elements are unable to form independent deposits, but are hosted within deposits of other elements as associated elements. Based on this, the study collected trace elemental data of pyrite, sphalerite, and chalcopyrite in various types of Se-Te bearing deposits. The optimal end-elements for distinguishing different genetic type deposits were recognized by principal component analysis (PCA) and the silhouette coefficient method, and discriminant diagrams were drawn. However, support vector machine (SVM) calculation of the decision boundary shows low accuracy, revealing the limitations in binary discriminant visualization for ore deposit type discrimination. Consequently, two machine learning algorithms, random forest (RF) and SVM, were used to construct ore genetic type classification models on the basis of trace elemental data for the three types of metal sulfides. The results indicate that the RF classification model for pyrite exhibits the best performance, achieving an accuracy of 94.5% and avoiding overfitting errors. In detail, according to the feature importance analysis, Se exhibits higher Shapley Additive Explanations (SHAP) values in volcanogenic massive sulfide (VMS) and epithermal deposits, especially the latter, where Se is the most crucial distinguishing element. By comparison, Te shows a significant contribution to distinguishing Carlin-type deposits. Conversely, in porphyry- and skarn-type deposits, the contributions of Se and Te were relatively lower. In conclusion, the application of machine learning methods provides a novel approach for ore genetic type classification and discrimination research, enabling more accurate identification of ore genetic types and contributing to the exploration and development of mineral resources.

Rational design and construction of highly efficient nonprecious electrocatalysts for oxygen reduction and alcohols oxidation reactions (ORR, AOR) are extremely vital for the development of direct oxidation alkaline fuel cells, metal‐air batteries, and water electrolysis system involving hydrogen and value‐added organic products generation, but they remain a great challenge. Herein, a bifunctional electrocatalyst is prepared by anchoring CuS/NiS2 nanoparticles with abundant heterointerfaces and sulfur vacancies on graphene (Cu1Ni2‐S/G) for ORR and AOR. Benefiting from the synergistic effects between strong interfacial coupling and regulation of the sulfur vacancies, Cu1Ni2‐S/G achieves dramatically enhanced ORR activity with long term stability. Meanwhile, when ethanol is utilized as an oxidant for AOR, an ultralow potential (1.37 V) at a current density of 10 mA cm−2 is achieved, simultaneously delivering a high Faradaic efficiency of 96% for ethyl acetate production. Cu1Ni2‐S/G also exhibits catalytic activity for other alcohols electrooxidation process, indicating its multifunctionality. This work not only highlights a viable strategy for tailoring catalytic activity through the synergetic combination of interfacial and vacancies engineering, but also opens up new avenues for the construction of a self‐driven biomass electrocatalysis system for the generation of value‐added organic products and hydrogen under ambient conditions. [ABSTRACT FROM AUTHOR]

Objective The aim is to screen out low pressure flash vapor mercury removal adsorbent suitable for mercury-containing natural gas treatment station. Methods The distribution of mercury in natural gas processing station was simulated by VMGSim software. A natural gas treatment station of a mercury-containing gas field in western China was selected as the test site and a set of mercury removal test equipment was designed and constructed. The mercury removal effect of four kinds of common high pressure mercury removal adsorbents in the low-pressure flash system was tested by field test. Results (1) The distribution of mercury simulated by VMGSim simulation software was close to the measured results in the natural gas treatment process, which has a certain guiding role for the design and production management of mercury-containing natural gas. (2) The adsorbent used for high pressure natural gas mercury removal could meet the requirements of low pressure flash vapor mercury removal emission standards. (3) The mercury removal effect of metal sulfide adsorbent was obviously better than that of activated carbon adsorbent. Conclusions Domestic adsorbent suitable for low pressure flash vapor mercury removal was screened out, and the low pressure flash vapor mercury removal process technology was formed, which can provide guidance and reference for low pressure flash vapor mercury removal process. [ABSTRACT FROM AUTHOR]

Propane dehydrogenation catalysts, containing Ni and Zn were synthesised with the following wt% (13:0, 11:2, 9:4, 6.5:6.5, 4:9, 2:11 and 0:13) ratios. Structural and textural properties showed that when Zn increased to > 4wt%, a NiZn alloy was formed. The improved catalytic activity for 6.5Ni–6.5Zn/SiO2, 4Ni–9Zn/SiO2 and 2Ni–11Zn/SiO2 was attributed to the formation of the NiZn alloy, with smaller particle size and blocked hydrogenolysis sites due to strong Ni–Zn interactions. Propene selectivity equalled 49%, 54% and 64% for the 6.5Ni–6.5Zn/SiO2, 4Ni–9Zn/SiO2 and 2Ni–11Zn/SiO2 catalysts compared to 0% for the monometallic 13Ni/SiO2 catalyst. In the Ni–Zn bimetallic system, zinc had a higher affinity for sulfur and inhibited the formation of a Ni–S phase. Propene selectivity increased from 8% for 9Ni–4Zn/SiO2 to 64% for 9Ni–4Zn/SiO2–S in three minutes of reaction time. Zinc and sulfur exhibited beneficial geometric and electronic effects, which affect particle size and olefin desorption for improved dehydrogenation activity. [ABSTRACT FROM AUTHOR]

Vanadium sulphide (VS4) nanosheets were synthesized by the hydrothermal method. The Polyaniline (PANI) and the VS4-PANI (PMCs) were synthesized by the in-situ polymerization method. The structural parameters were calculated from the PXRD pattern. The HR-SEM was used to record the surface morphology, which shows the interface between the VS4 and Polyaniline matrix. The absorption spectra and tauc plot were used to determine the optical band gap. To study the molecular interactions the Raman spectra was used. The synthesized materials were utilized to detect the presence of the metal ions such as Au3+ and Fe3+ (quenching) was using PL spectroscopy. [ABSTRACT FROM AUTHOR]

CoS2 and FeS2 nanoparticles with mesoporous structures embedded in carbon polyhedrons are prepared by reasonable design of materials (CoS2-FeS2-NC), which are used as a modified cathode material. This composite material can limit the shuttling of polysulfides and catalyze and adsorb polysulfides. Further, electrochemical properties of Li–S batteries are enhanced. Li–S batteries using S/CoS2-FeS2-NC electrodes have the best cycle and rate performance. The S/CoS2-FeS2-NC cathode's initial discharge capacity at 0.2C is 938.9 mAh g–1, while its reversible capacity remains 394.8 mAh g–1 after 200 cycles, with a 0.28% decline on average. S/CoS2-NC and bare sulfur cathodes have maximal discharging capacities of 82.3 and 63.8% of S/CoS2-FeS2-NC cathodes at 0.2C. The initial discharge capacity of S/CoS2-FeS2-NC at 0.5C is 795.6 mAh g–1, and the capacity of 354.4 mAh g–1 is maintained after 200 cycles. So, S/CoS2-FeS2-NC has excellent electrochemical properties. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is one of the most efficient strategies to generate clean energy H2. Herein, a novel hollow Co3S4/CuS@CoNi-LDH nanocomposite was designed. This hollow Co3S4/CuS@CoNi-LDH achieved OER overpotential of 220 mV, HER overpotential of 136 mV, respectively, at the current density of 10 mA cm−2. Notably, the hollow Co3S4/CuS@CoNi-LDH serving as both anode and cathode is assembled into a two-electrode water splitting device, and the potential of no more than 1.74 V is required to achieve the overall water splitting efficiency of 10 mA cm−2. This work provides a promising bifunctional catalyst for overall electrochemical water splitting.

Nicotinamide adenine dinucleotide (NAD(P)H) is an important energy carrier and charge transfer mediator in organisms. The efficient and regioselective reduction of NAD(P)+ to NAD(P)H is of significance in biocatalysis, nature and artificial photosynthesis, but remains challenging with artificial heterogeneous catalysts. Inspired by nature oxidoreductases where active centers are transition metal sulfide clusters, here we report that CoMo2.75Sx is efficient for the regiospecific electrocatalytic reduction of NAD+ to NADH, achieving a selectivity as high as 89 % for 1,4‐NADH. It is found that the adsorbed hydrogen and hydride formed on electrode surface are crucial for the selective formation of 1,4‐NADH. Based on isotopic effect, the C−H bond formation process by hydride transfer to NAD+ is inferred to be the rate‐determining step for NADH formation, which mimics enzyme catalyzed NADP+ reduction process in nature photosynthesis. [ABSTRACT FROM AUTHOR]