Ternary Sulfide Research Articles

Synthesis of CuCo2S4 nanosheets and its application in dye-sensitized solar cells

CuCo2S4, a ternary sulfide and an eco-friendly thiospinel that occurs naturally as a mineral named Carrollite, has been synthesized successfully in ambient conditions at low temperatures using ultrasonication. It has yet to be reported, but the nanosheet structure obtained from the ultrasonication synthesis method employed as a counter electrode in the dye-sensitized solar cells (DSSCs) has been demonstrated. The purity, crystallinity, morphology, and structure were explored thoroughly through the medium of XRD, SEM, TEM, SAED, and EDAX, and along with this, the presence of metal sulfide bond was investigated with the FT-IR and Raman spectra, which altogether confirmed the formation of CuCo2S4 nanosheet. The as-prepared nanosheets of CuCo2S4 have shown excellent homogeneity, as expected. Also, the presence of sulfur in the synthesized CuCo2S4, which is a highly polarizable atom and of a smaller size exhibiting a higher surface area, demonstrates higher electrocatalytic activity when fabricated as a counter-electrode in DSSCs by providing an incredible short circuit current density of 31.05 mA cm−2, open circuit potential of 735 mV with good fill factor value which altogether resulted in the power conversion efficiency of 10.21 % nearer to DSSC fabricated with Platinum counter electrode under the same conditions.

A novel method for engineering active sites through in-situ and chemical deposition: Robust Ni3S2/MoS2/WS2 heterostructures for efficient water splitting in an alkaline medium

To develop compact and efficient electrolysers, use a bi-functional electrocatalysts capable of performing both the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) at the same temperature, pressure, and pH. To develop ternary transition metal sulphides for OER and HER with superior performance. Herein, reported a sheet-like heterostructures electrode made of was fabricated on nickel foam using a simple hydrothermal method. The surface morphology and electrochemical active sites of the binder-free NMWS(1:1) heterostructures bi-functional catalyst were analysed in a 1.0 M KOH electrolyte medium to attain a lower overpotential for both OER (290 mV @ 10 mA cm−2) and HER (165 mV @ 10 mA cm−2). Electrochemical NMWS (1:1) studies show that the purported efficiencies are due to increased oxygen vacancies, interfacial bonds, and surface sulfur sites in the heterostructures were analysed through XPS, and HR-TEM. Furthermore, a dual-electrode in an electrolyser cell, the proposed heterostructures electrode achieved a current density of 10 mA cm−2 yet retained a remarkably low cell voltage of 1.73 V. The Ni3S2/MoS2/WS2 heterostructures stabilizes, which helps maintain LSV's low current degradation rate (CDR). The efficient water splitting has been calculated using turnover frequency and Tafel plot.

Facile one-pot synthesis of photoresponsive Cu1.8S and CuInS2 nanostructures aided by Cu-pyrimidylthiolate molecular precursor

Copper-based binary and ternary sulfides have attracted significant attention due to their excellent photo-physical properties, making them highly promising for high-performance energy harvesting and storage devices. This study focuses on the synthesis and structural characterization of an air-stable hexanuclear Cu-pyrimidylthiolate cluster complex which serves as an efficient single-source precursor for the preparation of Cu1.8S nanocrystals. Furthermore, coupling the molecular precursor with suitable indium source resulted in a facile one-pot pathway for the preparation of technologically important, copper-based ternary CuInS₂, nanocrystals. The crystal structure, phase purity, and compositions of the nanostructures were confirmed using PXRD, XPS, EDS, and area elemental mapping. Electron microscopic studies revealed the formation of polygonal and hexagonal morphology with varied size in Cu1.8S and CuInS₂ nanocrystals respectively. UV-Vis diffuse reflectance spectroscopy showed a slight blue shift in the band gap of the nanostructures compared to their bulk counterparts which can be attributed to quantum confinement or surface lattice distortion effects. The band gap of the pristine nanocrystals along with high photocurrent and stable photo-switching characteristics suggest that they can serve as suitable electrode material for optoelectronic and photodetector devices.

High performance long-afterglow phosphor-based ZnIn2S4/Sr2MgSi2O7:Eu2+,Dy3+ photocatalyst capable of dark state long-term application for photocatalytic sterilization

Eco-friendly photocatalytic sterilization utilizing solar energy via the generation of reactive radicals excited by light irradiation devastating bacterial cells and mineralizing organic pollutants effectively exhibits vast application potential in marine biofouling prevention due to the abundant solar energy available in the ocean. Focusing on the issue of the cessation of photocatalytic processes in the absence of light, in this study, we selected the long afterglow material Sr2MgSi2O7:Eu2+,Dy3+ (SMSO), which exhibits persistent sky-blue luminescence after brief illumination, as the substrate for in situ compositing with the visible-light-responsive ZnIn2S4 (ZIS). The emission spectrum of SMSO partially overlaps with the absorption spectrum of ZIS, and their energy bands were well-matched. Consequently, the ZIS/SMSO=1:0.5 (mass ratio) exhibited the synergistic degradation and bactericidal performance under both light and dark conditions. ZIS/SMSO=1:0.5 exhibited the degradation rate of methyl orange (MO) of 72.4 % when exposed to 5 minutes of simulated sunlight, 2.6-fold increase compared to ZIS, and especially, it exhibited the sustained degradation rate of 38.7 % after 5 h in darkness. Besides, ZIS/SMSO=1:0.5 exhibited the bactericidal rate of 28.9 % under simulated visible light of 1 h, which was 2.9 and 2.5 times the bactericidal rate of ZIS and SMSO, respectively; and especially, after 6 h in darkness, it reached 64.4 %, which was 2.8 and 1.9 times the bactericidal rate of ZIS and SMSO, respectively. The Electron Spin Resonance (ESR) test validated the notably higher ·OH and ·O2- signals of the ZIS/SMSO=1:0.5 complex than those of individual components when exposed to light, and the sustained existence of ·OH signal even in darkness, revealing that the continuously generation of active free radicals even in the absence of light due to that the SMSO can continuously excite the ZIS. Combining with the in situ XPS analysis and the density functional theory calculations, an S-scheme heterojunction between ZIS and SMSO is formed which contribute to the higher yield of ·OH for ZIS/SMSO=1:0.5 under both light and dark conditions. And the calculation of the adsorption energies of ZIS and SMSO for O2 and OH- in the composite revealed that the ZIS component is more favorable for adsorbing O2, while the SMSO component is more favorable for adsorbing OH-. These analyses manifested the S-scheme electron transfer of the system. Finally, the ZIS/SMSO=1:0.5 composite of environmentally friendly broad-spectral-responsive ternary metal sulfides with the long afterglow materials is capable of a sustained degradation and bactericidal effect, not only under light irradiation but also in the subsequent darkness. It offers valuable insights into photocatalytic materials that overcome light availability limitations for preventing marine biofouling.

Design of a yolk-shell ternary metal sulfide with a tunable structure for high-performance electromagnetic wave absorption.

Herein, we report a strategy for preparing a novel ternary metal sulfide (TMS) with a yolk-shell structure based on a "penetration-solidification-annealing" method. A series of FeCoNiSxGy with tunable structure, different morphology and composition was synthesized by adjusting the degree of sulfuration. Due to the synergistical manipulation of rich interface, defects, vacancies and electrical conductivity, as well as the unique yolk-shell structure, the appropriate sulfuration strategy achieved excellent impedance-matching and strong dielectric loss. The as-synthesized FeCoNiSxGy sulfides were blended with paraffin wax (under a filler loading of 30 wt%), which had the minimum reflection loss of -49.44 dB (2.20 mm) and the effective absorption bandwidth of 4.76 GHz (1.6 mm). In conclusion, this work could aid the design and regulation of a new type of ternary metal sulfides with high-performance electromagnetic wave absorption.

Constructing high efficient carrier channels in double ternary compounds MoSSe/CdSSe heterojunction for photoelectrochemistry and electrocatalytic hydrogen production

Here is a demonstration of constructing MoSSe/CdSSe heterojunction catalyst from bimetallic selenium sulfides. CdSSe has a high conduction band position of −0.65 eV, resulting in a strong reduction potential of photogenerated electrons. However, the high resistance of CdSSe affects the transport of charge carriers. In addition, experiments have confirmed that the presence of S and Se in MoSSe and CdSSe enhances their chemical activity and facilitates bonding. A better connection can be formed between MoSSe and CdSSe, resulting in high carrier transport efficiency. In the X-ray photoelectron spectroscopy results, the Mo and Se signals showed a large shift nearly 1 eV which confirms the strong binding between MoSSe and CdSSe. In the photoelectrochemical tests, the MoSSe/CdSSe heterojunction demonstrated a photocurrent density of 3.097 mA/cm2 at 0 V (RHE) which is 2.7 and 2.9 times that of MoSSe (1.227 mA/cm2) and CdSSe (1.127 mA/cm2) respectively with a low resistance of 161 Ω. Moreover, the MoSSe/CdSSe also has good electrocatalytic hydrogen evolution performance with an overvoltage of 180 mV and Tafel slope of 69 mV/dec. Fluorescence and photocurrent response tests confirmed its higher carrier separation efficiency. This work demonstrates the application of ternary metal selenium sulfide heterojunctions in catalytic energy materials.

An empirical approach-based analysis for the exploration of ternary metal sulfide as an active and selective CO2 reduction electrocatalyst

An empirical approach-based analysis for the exploration of ternary metal sulfide as an active and selective CO2 reduction electrocatalyst

Advancing Sustainable Quinolines Synthesis via ZnIn2S4 Heterogeneous Photocatalysis

In this study, we report a sustainable, visible light and heterogeneous photocatalytic system to address these issues, using the ternary sulfide ZnIn2S4 (ZIS) as a photoredox catalyst. Our protocol uses visible light irradiation to activate the photoredox catalyst, generating acyl radicals from aldehydes. The methodology demonstrated a broad substrate scope and commendable recyclability. The method also proved capable of scaling to the gram level while maintaining high efficiency, thus highlighting the robustness and reusability of ZIS. This work not only proposes a novel method for the heterogeneous photocatalytic Minisci-type alkylation reaction, but also contributes a valuable approach towards enhancing the efficacy and sustainability of photocatalysts within the pharmaceutical industry.

Dimers and 2D Networks of Adamantane-Related Ternary Organosilicon Coinage Metal Sulfide Clusters.

Adamantane-type organotin sulfide clusters were recently shown to react with coinage metal phosphine complexes under replacement of an organic substituent by a metal-phosphine unit. An extension of such studies involving the silicon-based congener [(PhSi)4S6] (A) revealed that the cluster core will be partly disassembled and a {PhSi} moiety is replaced by a coinage metal phosphine complex to form [(Et3PAg)3(PhSi)3S6] (B) and [Na2(thf)2.33][(Me3PCu)(PhSi)3S6] (C). Herein, we present an extension of this work upon variation of the reactants and reaction conditions. Besides the isolation of crystalline precursor complexes [CuCl(PMe2Ph)3] (1) and [AgCl(PMe2Ph)2]2 (2), the study addresses reactions of A with AgCl and a phosphine ligand in CH2Cl2, upon which A is completely disassembled to form [(Ph3P)3Ag(μ-S)SiCl2Ph] (3). In another case a CH2 group, most likely stemming from CH2Cl2, was attached to the ligand, thus generating [{PhCl(S)SiSCH2P(Ph2)CH2CH2}2] (4). Upon using CuCl and 1,4-bis(diphenylphosphino)butane (dppb) we isolated the phosphine-bridged analog of B, [{(dppbCu2)CuP(Ph2)(CH2CH2)(PhSi)3S6}2] (5). In order to receive the yet elusive silver homolog of C, we used PMe2Ph as a bulkier ligand. This way we generated a 2D coordination polymer of the desired composition, [Na2(thf)1.5][(Me2PhPAg)(PhSi)3S6] (6). UV-visible spectra of 6 indicated a bandgap of 3.89 eV, thus blue-shifted in regards to B and C.

Optimisation of Mo doping to form NiCoMo ternary sulphides for high performance charge storage.

Multi-component synergy and the rational design of structures are effective methods for preparing electrode materials for high-performance energy storage devices. Transition metal-based hydroxides offer advantages such as a large specific surface area, large interlayer spacing, multiple redox states, and high theoretical capacity, making them commonly used as positive materials for supercapacitors. However, challenges like low conductivity and severe agglomeration limit their practical application. This study focuses on the preparation of Ni, Co, and Mo ternary transition metal hydroxides by incorporating the Mo element to optimize their structure. Furthermore, sulfide ions were utilized in an ion exchange process to replace hydroxides, resulting in the formation of NiCoMo ternary sulfide electrode materials. By adjusting the amount of Mo added, a spherical nanoneedle-shaped N2C1MS0.2-2 electrode material was successfully synthesized. This electrode exhibited a specific capacity of 2094 F g-1 at a current density of 1 A g-1. In addition, an asymmetric supercapacitor was assembled with activated carbon as the negative electrode and N2C1MS0.2-2 as the positive electrode, which had an energy density of 46.2 W h kg-1 at a power density of 800 W kg-1, a capacity retention of 89.7% and a coulombic efficiency of 97.8% after 10 000 cycles. This study provides a reference for the design and preparation of ternary sulphide electrode materials.

Lanthanum Transition-Metal Sulfide Electrocatalysts for Overall Water Splitting

Hydrogen has been identified as a sustainable energy source for the future with the potential of replacing fossil fuels due to its high gravimetric energy density and zero carbon emissions. Water electrolysis is a promising approach to the clean production of pure hydrogen, however, the benchmark catalysts of the half reactions of water electrolysis are noble-metal based, which limit the application of this technique.1 As well, the high energy barrier and sluggish kinetics of the oxygen evolution reaction limit the efficiency of the system. Therefore, it is crucial to develop robust, stable, and cost-effective materials for water electrolysis to be scalable. Lanthanum transition-metal oxide electrocatalysts have been pursued in the past for water splitting due to the high abundance of lanthanum and transition metals.2 However, these catalysts suffer from low conductivity and inherent instability towards oxygen evolution. Binary sulfides, selenides, and phosphides have also been pursued,3 but the compositional space of these materials is limited. Ternary sulfides offer a wider compositional space that allows fine-tuning for optimal performance. As a result, we have pursued the synthesis and application of the relatively unexplored ternary chalcogenides, LaMS3 (M = Ni, Co, Fe, Mn) towards water electrolysis. The efficiency of water electrolysis and stability of the materials have been tested with linear sweep voltammetry, galvanostatic measurements, and electrochemical impedance spectroscopy. We found these materials to be active towards both the hydrogen and oxygen evolution reactions, in acidic and alkaline conditions, respectively, with the catalysts exhibiting an activity trend where LaNiS3 > LaCoS3 > LaFeS3 > LaMnS3. For HER, LaNiS3 exhibits an overpotential of 340 mV at 10 mAcm-2 with a Tafel slope of 79 mV/decade. For OER, an overpotential of 373 mV at 10 mAcm-2 and a low Tafel slope of 48 mV/decade are observed. In addition, LaNiS3 proved to be highly stable with minimal change in potential over a period of 18 hours. The high activity and stability of LaNiS3 towards both half reactions of water electrolysis make it a promising candidate for a bifunctional water splitting electrocatalyst.References Wang, S.; Lu, A.; Zhong, C.-J. Hydrogen Production from Water Electrolysis: Role of Catalysts. Nano Convergence 2021, 8 (1), 4.Dias, J. A.; Andrade, M. A. S.; Santos, H. L. S.; Morelli, M. R.; Mascaro, L. H. Lanthanum‐Based Perovskites for Catalytic Oxygen Evolution Reaction. ChemElectroChem 2020, 7 (15), 3173–3192.Anantharaj, S.; Ede, S. R.; Sakthikumar, K.; Karthick, K.; Mishra, S.; Kundu, S. Recent Trends and Perspectives in Electrochemical Water Splitting with an Emphasis on Sulfide, Selenide, and Phosphide Catalysts of Fe, Co, and Ni: A Review. ACS Catal. 2016, 6 (12), 8069–8097.

Efficient CdIn2S4/MgIn2S4 heterojunction for ultrasensitive detection of lung cancer marker neuron-specific enolase

In this work, a photoelectrochemical (PEC) immunosensor was constructed for the ultrasensitive detection of lung cancer marker neuron-specific enolase (NSE) based on a microflower-like heterojunction of cadmium indium sulfide and magnesium indium sulfide (CdIn2S4/MgIn2S4, CMIS) as photoactive material. Specifically, the well-matched energy level structure and narrow energy level gradients between CdIn2S4 and MgIn2S4 could accelerate the separation of electron-hole (e−-h+) pairs in the CMIS heterojunction to enhance the photocurrent of CMIS, which was increased 5.5 and 80 times compared with that of single CdIn2S4 and MgIn2S4, respectively. Meanwhile, using CMIS as photoactive material, increasing the biocompatibility by dropping Pt NPs on the surface of CMIS to immobilize the antibody through Pt–N bond. Fe3O4-Ab2, acting as the quencher, competitively consumes electron donors and absorbs light, leading to photocurrent quenching. With the increasing of quencher, the photocurrent decreased. Hence, the developed “signal-off” PEC immunosensor realized the trace detection of NSE within the range from 1.0 fg/mL to 10 ng/mL with a low detection limit of 0.34 fg/mL. This strategy provided a new perspective for establishing ternary metal sulfide heterojunction to construct PEC immunosensor for sensitive detection of disease biomarkers.

Structural optimization: Ternary FeNiZn sulfide nanoparticles anchored on nanosheets to strengthen oxygen evolution reaction

Enhancing the activity of oxygen evolution reaction (OER) is crucial for improving the efficiency of electrochemical water splitting (EWS). The highly adjustable electronic structure and potential high conductivity of transition metal sulfides (TMSs) make them promising candidates for OER electrocatalysts. Herein, we have synthesized trimetallic sulfides Fe2Ni1Zn1–S(II) based on layered double hydroxides (LDHs) precursor employing a facile and efficient two-step solvothermal approach. Benefitting from the multi-metallic synergistic effect and the distinctive interfacial structure, Fe2Ni1Zn1–S(II) shows excellent electrocatalytic OER performance (η10 = 252 mV, Tafel slope = 64.2 mV∙dec−1). Meanwhile, it has outstanding stability (50 h) in 1 M KOH, which is better than RuO2 and many other metal sulfide electrocatalysts. Furthermore, it was found that the structure of the catalyst was still retained after OER test, which further verified its catalytic stability. This work supplies an effective route for the preparation of LDHs derived multi-metallic sulfides.

The synergistic effect of Cd-doped and S-vacancies in CdxZn1-xIn2S4 2D nanosheets for high-performance triethylamine sensing

Ternary metal sulfides with suitable band gaps, high physicochemical stability, and unique two-dimensional (2D) nanostructures are expected to be the next-generation high-performance gas sensors following the MOS type. Doping engineering is utilized as an effective strategy to improve the semiconductor surface activity and enhance its gas-sensitive properties. In this paper, the energy band structure and surface chemical oxygen of ZnIn2S4 (ZIS) materials was tuned by selectively introducing substitutional Cd to replace the Zn sites in ZIS crystals. Meanwhile, the introduction of Cd-ions brings more abundant S vacancy defects, enhances the acid-base interactions at the interface, and pushes the extent of surface redox reactions. In addition, by combining the strong adsorption of ZIS to triethylamine, the CdxZn1-xIn2S4 nanosheets achieved highly improved sensing properties, including better response (63.38–100 ppm), enhanced selectivity (STEA/sother = 12.9), and accelerated response/recovery (4 s/32 s). The results confirm the feasibility of developing low-cost, high-performance 2D metal sulfide gas sensing materials through rational structural design and optimization.

A novel nickel cobalt sulfide-indium (hydroxy) sulfide [NiCo2S4@In(OH)xSy] composites for LAGP-based all-solid-state lithium-ion capacitors

Metal sulfides have attracted the attention of researchers as electrode materials in energy storage systems because of their superior electrochemical performance. In this study, we synthesized a nickel cobalt sulfide@indium(hydroxy) sulfide nanoarchitecture (NiCo2S4@In(OH)xSy) using a one-step hydrothermal method and investigated its potential as a high-performance anode material for lithium-ion capacitors (LICs). The volume expansion of sulfides during charge-storage can be reduced by fabricating suitable ternary sulfide composites. This unique composite highlights the importance of –OH bonding for better charge kinetics. The NiCo2S4@In(OH)xSy composite nanoarchitecture as an anode can achieve a high specific capacity of 1277 mA h g−1 at 0.1 A/g, high rate capability, and long cycling performance. Furthermore, the all-solid-state LIC device fabricated using NiCo2S4@In(OH)xSy as anode, activated carbon as cathode, and LAGP (Li1.5Al0.5Ge1.5P3O12)-based solid-state electrolyte/separator can deliver a high energy density of 172.4 Wh kg−1 at 423.5 W kg−1 and 70.6 Wh kg−1 even at a high power density of 8470 W kg−1.

Electronic and optical properties of ternary kagome Rb2Ni3S4: a density functional study

The application of semiconductors with optical properties has grown significantly in the development of semiconductor photovoltaics. Here, we explore the electronic and optical properties of ternary transition metal sulfide Rb2Ni3S4 by means of density functional theory. From the structural perspective, Ni atoms are found to form a kagome-like lattice in a two-dimensional plane of Rb2Ni3S4. From our calculations, Rb2Ni3S4 is found to be a semiconductor with an indirect band gap of ∼0.67 eV. Strong hybridization was observed between the S-3p with the Ni-3d xz and Ni-3d yz orbitals. Interestingly, a flat band was noticed below the Fermi level demonstrating one significant feature of kagome lattice. From the optical calculations, Rb2Ni3S4 is found to exhibit optical activity in both the visible and lower ultraviolet regions of the incident photon energies. The optical response suggests this material may be a potential candidate for opto-electronic device, given its ability to interact with light across a broad range of wavelengths. This work is expected to motivate the experimental group for transport measurements and may provide a new foundation in optics.

Deciphering the energy storage and electro‐catalytic potential of the BaLa2MnS5 ternary metallic sulfide prepared via single source precursor route

AbstractThe present work elucidates the first report on the synthesis and energy applications of the novel BaLa2MnS5 prepared from single source precursor route. This metal chalcogenide expressed a tuned band gap of 3.84 eV and an average crystallite size of 20.52 nm. Functional groups explored for BaLa2MnS5 expressed strong signals for presence of the metal sulfide bonds. The thermal decomposition pattern of BaLa2MnS5 followed a two‐phased mechanism. Synthesized metal sulfide possessed an irregular morphology with particles arranged in random manner. An assessment of the chalcogenide BaLa2MnS5 for energy applications has been carried out. When employed as an electrode material in 1 M KOH, which acted as the background electrolyte, BaLa2MnS5 chalcogenide showed a specific capacitance of 597 F g−1. Furthermore, this BaLa2MnS5 chalcogenide decorated electrode has a low resistance, as shown by the Rs of 1.35 Ω, and a specific power density of 7366 W kg−1, according to the impedance investigations. The electrochemical results for the OER activity are indicative of the OER overpotential and Tafel slope values as 388 mV and 108 mV/dec. This electrode achieved the HER overpotential value of 241 mV while the obtained Tafel slope was 194 mV/dec.

Are Selenides the Same as Sulfides? Structure, Spectroscopy, and Properties of Narrow-Gap Rare-Earth Semiconductors RE2Sn(S1-xSex)5 (RE = La, Ce; x = 0-0.8).

The ternary rare-earth sulfides RE2SnS5 (RE = La-Nd) and the partial solid solutions RE2Sn(S1-xSex)5 (RE = La, Ce; x = 0-0.8) were prepared in the form of polycrystalline samples by reaction of the elements at 900 °C and as single crystals in the presence of KBr flux. They adopt the La2SnS5-type structure (orthorhombic, space group Pbam, Z = 2) consisting of chains of edge-sharing SnCh6 octahedra separated by RE atoms. Although the cell parameters evolve smoothly in RE2Sn(S1-xSex)5, detailed structural analysis by single-crystal X-ray diffraction revealed a pronounced preference for the Se atoms to occupy two out of the three chalcogen sites, which offers a rationalization for why the all-selenide end-members RE2SnSe5 do not form. Solid-state 119Sn NMR spectra confirmed the nonrandom distribution of SnS6-nSen local environments, which could be resolved into individual resonances. The Raman spectra of RE2SnS5 compounds show an intense peak at 307-320 cm-1 assigned to a symmetric A1g mode, which is dominated by Sn-S bonds; the Raman peak intensities varied with Se substitution in La2Sn(S1-xSex)5. Optical diffuse reflectance spectra, band structure calculations, and electrochemical impedance spectra indicated that these compounds are narrow band gap semiconductors; the optical band gaps are insensitive to RE substitution in RE2SnS5 (0.7 eV) but they gradually decrease with greater Se substitution in RE2Sn(S1-xSex)5 (0.7-0.4 eV).

CdS/Bi2S3/NiS ternary heterostructure-based photoelectrochemical immunosensor for the sensitive detection of carbohydrate antigen 125

The sensitive, accurate and rapid detection of carbohydrate antigen 125 (CA125) is essential for the early diagnosis and clinical management of ovarian cancer, but there is still challenge. Herein, a photoelectrochemical (PEC) immunosensor based on CdS/Bi2S3/NiS ternary sulfide heterostructured photocatalyst was presented for the detection of CA125. The CdS/Bi2S3/NiS was synthesized by a one-step hydrothermal approach. The heterojunction comprising of CdS and Bi2S3 could separate photogenerated carriers, the introduced narrow bandgap NiS could act as electron-conducting bridge to facilitate the transfer of interfacial photogenerated electrons, thereby improving the photoelectric conversion efficiency. Due to their synergistic effect, the photocurrent response produced by the composite was up to 14.6 times of pure CdS. On the basis, a PEC immunosensor was constructed by introducing the CA125 antibody through thioglycolic acid linkage. It was found that the resulting immunosensor showed good performance. Under the optimized conditions, its linear detection range was as wide as 1 pg mL−1−50 ng mL−1, and the detection limit was low to 0.85 pg mL−1. Furthermore, we experimentally tested its anti-interference, stability and reproducibility, and satisfactory results were achieved. The practicable feasibility of the sensor was confirmed by testing serum sample. Thus this work provided a simple, fast and enough sensitive approach for CA125 monitoring.

Design and performance evaluation of hierarchical ZnCo2S4@PANI core-shell nanorod arrays for high-efficiency supercapacitor applications

Ternary transition metal sulfides (TMS) have gained significant attention due to their excellent energy and power density as Faradaic electrode materials to be utilized in supercapacitors (SCs). Among various conducting polymers, polyaniline (PANI) has rapidly evolved as a valuable pseudo-capacitor material. Though it deprived cycling stability due to instability in structural transformation, which is the major obstacle to its practical level utilization in energy related applications. Herein, the synthesis of an efficient and reliable ZnCo2S4@PANI nonorod arrays (NRAs) anode with structure-to-performance hierarchical morphology is designed to achieve excellent performance. Heterostructured, extremely porous ZnCo2S4 nanorods have acted as a conductive core, which has provided the strain-buffer-support, along with nanoscaled PANI layer to act as an electrochemical active counterpart, and has demonstrated outstanding specific capacitance while retaining the remarkable cyclic performance and rate capability. Implementing the perfectly uniform and compactly coated PANI, the synthesized anode has demonstrated a high specific capacitance of ∼815 F g−1 at a current density of 1 A g−1 and exceptional ∼91 % capacitance retention even after 4000 cycles at high 2 A g−1 current density. Such outcomes are much superior to the most reported electrochemical performances of PANI-related pseudo-capacitors in the literature. The enhanced electrochemical properties of the as synthesized ZnCo2S4@PANI NRAs anode demonstrate the ability of the stable componential structure as a hybrid electrode design to provide a new direction for researchers to utilize such porous framework as an operative support for proficient energy storage devices.