Sulfide Nanowires Research Articles

NO2 sensing with CdS nanowires at room temperature under green light illumination

Detection of ppb-level NO2 gas under atmosphere is urgent to meet the requirements of the rapidly developing internet of things. Compared with traditional sensing methods, light illumination has been considered as a key approach for excellent gas sensor performance under moderate conditions. Herein, we developed a green-light-assisted gas sensor based on cadmium sulfide nanowires (CdS NWs) that has good NO2 sensing capability at ambient temperature. The response values of NO2 are 236% and 11% to 10 ppm and 12.5 ppb, respectively. Furthermore, the CdS NWs sensor has a high selectivity for NO2 over a variety of interference gases, as well as good stability. The cleaning light activation and the sulfur vacancy-trapped charge behavior of CdS NWs are observed, which suggest a light-assisted sensing mechanism. These results suggest that light-induced charge separation behavior might significantly improve gas-sensing characteristics.

Synthesis of silver sulfide nanowires: Variation of the morphology and structure

The beaded string silver sulfide nanowires (Ag2S NWs) are produced by the sulfuration reaction between silver nanowires (Ag NWs) and sodium polysulfide (Na2Sx) within the aqueous solution at room temperature. The reaction was preferentially initiated at the tip and defect of the Ag NWs, and the volume expansion occurs at the sulfurized sites due to the larger volume of silver sulfide (Ag2S) than silver (Ag). As the reaction progresses, the sulfurized area spreads around, resulting in multiple protrusion of the Ag-Ag2S hybrid nanowires. The lag reaction position to be unable to embed enough sulfur atoms due to the extrusion stress of expansion on both sides, leading to the formation of the flat bamboo joint sandwiched between bulges finally. This paper describes the structure evolution and morphology transformation of Ag NWs during the sulfuration process, and focuses on the studying of sulfuration mechanism.

Ultrafast-response and broad-spectrum polarization sensitive photodetector based on Bi1.85In0.15S3 nanowire

Alloying of semiconductors is a good strategy to manipulate their electronic band structures, which can broaden the photoresponse range of the corresponding optoelectronic devices. In addition, building a Schottky diode and improving the crystal quality of the channel semiconductor can improve the photoresponse speed of the optoelectronic device. Here, we report the design and preparation of Bi1.85In0.15S3 nanowires by a facile chemical vapor transport method. The individual Bi1.85In0.15S3 nanowire photodetectors realize excellent photoresponse in a broadband range from solar-blind deep ultraviolet (266 nm) to near-infrared (830 nm), and the obtained maximum external photoresponsivity of 95.99 A/W and detectivity of about 3.52×1011 Jones at 638 nm. Furthermore, the photodetectors also exhibit the ultrafast photoresponse speed with the rise time of 190 ns and the fall time of 180 ns, owing to the high crystal quality and the Schottky contacts between the Au electrodes and nanowires. In addition, the photoresponse of photodetectors is polarization angle sensitive in a broadband range from 266 to 808 nm, and the obtained maximum dichroic ratio is 3.54 at 808 nm, which results from the structural anisotropy of the Bi1.85In0.15S3 crystal. These performances are superior to the reported Bi2S3, In2S3, and other Bi or In sulfide nanowire photodetectors. The results render (BixIn1−x)2S3 photodetectors have significant application potentials in multifunctional optoelectronics and electronics.

Mushroom-like Graphene Nanosheets/Copper Sulfide Nanowires Foam with Janus-Type Wettability for Solar Steam Generation

Mushroom-like Graphene Nanosheets/Copper Sulfide Nanowires Foam with Janus-Type Wettability for Solar Steam Generation

Photothermal Synthesis of Copper Sulfide Nanowires for Direct Lithography of Chalcogenides on a Chip

Photothermal Synthesis of Copper Sulfide Nanowires for Direct Lithography of Chalcogenides on a Chip

Photoelectron Transfer Mediated by the Interfacial Electron Effects for Boosting Visible-Light-Driven CO2 Reduction

Imine-linked covalent organic frameworks (COFs) are popular candidates for photocatalytic CO2 reduction, but high polarization of the imine bond is less efficient for π-electron delocalization between the linked building units, leading to low intramolecular electron transfer and poor photocatalytic efficiency. Herein, we present a structural and electronic engineering strategy through integrating the imine-linked COF consisting of Zn–porphyrin and Co–bipyridyl units with cadmium sulfide (CdS) nanowires to form a CdS@COF core–shell structure. The experimental and theoretical results have validated that CdS serves as the electron transfer channel through the interfacial electron effects, which induces photoelectron transfer from Zn–porphyrin to CdS and subsequent injection into Co–bipyridyl units for CO2 reduction. The as-prepared CdS@COF generates 4057 μmol g–1 CO in 8 h under visible-light irradiation, which is considerably higher than those of its neat CdS and imine-linked COF counterparts. This work provides protocols to tackle intramolecular charge transfer across polar linkages between photosensitizers and active sites for solar-to-chemical energy conversion.

Stacking Engineered Room Temperature Ferroelectricity in Twisted Germanium Sulfide Nanowires

AbstractGroup‐IV monochalcogenides have emerged with immense potential to be used as ferroelectric materials in recent times. However, in most of them, ferroelectricity is limited by the presence of inversion symmetry in their natural crystal structure. Here, an experimental observation of ferroelectric order at room temperature by introducing Eshelby twist in Germanium sulfide (GeS) nanowires is reported. The twisted nanowires are synthesized by low‐pressure chemical vapor deposition. The existence of room temperature ferroelectricity in a single nanowire is confirmed by electrical measurements, piezoelectric force microscopy, and second harmonic generation spectroscopy. Density functional theory calculations reveal that the twist in the GeS nanowires breaks the inversion symmetry where the inversion symmetry breaking phonon modes get hardened giving rise to ferroelectricity. These results are expected to be useful in making non‐volatile memory devices, flexible electronics, electronic sensors, and neuromorphic computing.

Orientation and ellipticity dependence of high-order harmonic generation in nanowires

It has been predicted that high-order harmonic generation (HHG) in nanowires has the potential to scale up photon energy and harmonic yield. However, studies on HHG in nanowires are still theoretical and no relevant experimental results have been reported as yet. Our experimental observation of the high-order harmonic in cadmium sulfide nanowires (CdS NWs) excited by a mid-infrared laser is, to our knowledge, the first of such study, and it verifies some of the theoretical results. Our experimental results show that the observed harmonics are strongest when a pump laser is parallel to the nanowires. Therefore, the theoretical prediction that harmonics are strongest under the nanowires parallel to the laser field is confirmed experimentally, and this can be used to determine the orientation of the nanowire. In addition, harmonics are sensitive to the variation of pump light ellipticities. This orientation dependence opens new opportunities to access the ultrafast and strong-field physics of nanowires.

Aerosol-assisted chemical vapor deposition of nickel sulfide nanowires for electrochemical water oxidation

Slow kinetics and emotive design of electrocatalysts are the main barriers to effective oxygen evolution and hydrogen production from water. To overcome these challenges, nickel sulfide impregnated electrocatalysts with auxiliary structural features have recently attracted attention as effective alternatives for the oxygen evolution reaction (OER). Herein, nickel sulfide (NiS) nanowires are developed directly on nickel foam (NF), which have proven to be a highly efficient electrocatalyst for OER in an alkaline medium. For this, NiS nanowires were grown on NF for short intervals of 30, 60, 90 and 120 min through an aerosol-assisted chemical vapor deposition (AACVD) process using nickel diethyldithiocarbamate as a precursor. The as-developed NiS electrode showed excellent OER activity in 1.0 M KOH solution. It is noteworthy that the NiS electrode produced after 90 min provides a reference current density of 10 mA cm−2 at an overpotential (η) of 210 mV and achieves a higher current density of 500 mA cm−2 at an overpotential of 340 mV. Moreover, the nanocatalyst has observed a low Tafel value (60 mV dec−1) and good OER stability. After the electrolysis, it was found that the surface of the NiS catalyst was partially modified into nickel oxide. The S atom in the NiS catalyst can provide an activator function that first converts the sulfide to a hydroxide and then eventually becomes an oxyhydroxide species. The more active nickel hydroxide/oxyhydroxide phase raises the water oxidation performance to a new level. The facile synthesis of NiS nanowire films by AACVD tends to be used as an anodic material in various other power generation and energy conversion devices such as batteries, fuel cells, and supercapacitors.

Photodegradation Process of Organic Dyes in the Presence of a Manganese-Doped Zinc Sulfide Nanowire Photocatalyst.

Zinc sulfide (ZnS) nanowires represent a promising candidate in many fields, including optoelectronics and photocatalysis because of their advantages such as excellent optical properties, chemical stability and an easy-scalable simple synthesis method. In this study, an energy-friendly microwave radiation process was used to develop the single-step, solvothermal process for the growth of manganese-doped zinc sulfide (ZnS) and undoped nanocrystals (NCs) in the forms of nanowires using two short amines as a stabilizer, e.g. ethylenediamine and hydrazine, respectively. ZnS nanowires doped with Mn atoms show absorbance in UV and in the visible region of the spectrum. The photocatalytic degradation of rhodamine B in the presence of Mn-doped and undoped ZnS nanocrystals illuminated with only a 6-W UV lamp has been comprehensively studied. The effect of Mn doping and the presence of a nanocrystal stabilizer on the degradation process was determined. It was found that the efficiency of a photocatalytic degradation process was strongly affected by both factors: the doping process of nanowires with Mn2+ atoms and the attachment of ligands to the nanocrystal surface.

Fabrication of Polyoxometalate Anchored Zinc Cobalt Sulfide Nanowires as a Remarkable Bifunctional Electrocatalyst for Overall Water Splitting

AbstractThe advancement of a naturally rich and effective bifunctional substance for hydrogen and oxygen evolution reaction is crucial to enhance hydrogen fuel production efficiency via the electrolysis process. Herein, facile and scalable hydrothermal synthesis of bifunctional electrocatalyst of polyoxometalate anchored zinc cobalt sulfide nanowire on Ni‐foam (NF) for overall water splitting is reported for the first time. The electrochemical analysis of POM@ZnCoS/NF displays significantly low HER and OER overpotentials of 170/337 and 200/300 mV to attain a current density of 10/40 and 20/50 mA cm−2, respectively, demonstrating the notable performance of POM@ZnCoS/NF toward H2 and O2 evolution reaction in alkaline medium. Additionally, the electrolyzer consisting of the POM@ZnCoS/NF anode and cathode shows an appealing potential of 1.56 V to deliver 10 mA cm−2 current density for overall water splitting. The high electrocatalytic activity of the POM@ZnCoS/NF is attributed to modulation of the electronic and chemical properties, increment of the electroactive sites and electrochemically active surface area of the zinc cobalt sulfide nanowires due to the anchorage of polyoxometalate nanoparticles. These results demonstrate the advantage of the polyoxometalate incorporation strategy for the design of cost‐effective and highly competent bifunctional catalysts for complete water splitting.

Strong coupling of a plasmonic nanoparticle to a semiconductor nanowire

Abstract By placing a single Au nanoparticle on the surface of a cadmium sulfide (CdS) nanowire, we demonstrate strong coupling of localized surface plasmon resonance (LSPR) modes in the nanoparticle and whispering gallery modes (WGMs) in the nanowire. For a 50-nm-diameter Au-nanosphere particle, strong coupling occurs when the nanowire diameter is between 300 and 600 nm, with a mode splitting up to 80 meV. Using a temperature-induced spectral shift of the resonance wavelength, we also observe the anticrossing behavior in the strongly coupled system. In addition, since the Au nanosphere has spherical symmetry, the supported LSPR mode can be selectively coupled with transverse electric (TE) and transverse magnetic (TM) WGMs in the nanowire. The ultracompact strong-coupling system shown here may provide a versatile platform for studying hybrid “photon–plasmon” nanolasers, nonlinear optical devices, and nanosensors.

Orbital-Angular-Momentum-Controlled Hybrid Nanowire Circuit.

Plasmonic nanostructures can enable compact multiplexing of the orbital angular momentum (OAM) of light; however, strong dissipation of the highly localized OAM-distinct plasmonic fields in the near-field region hinders on-chip OAM transmission and processing. Superior transmission efficiency is offered by semiconductor nanowires sustaining highly confined optical modes, but only the polarization degree of freedom has been utilized for their selective excitation. Here we demonstrate that incident OAM beams can selectively excite single-crystalline cadmium sulfide (CdS) nanowires through coupling OAM-distinct plasmonic fields into nanowire waveguides for long-distance transportation. This allows us to build an OAM-controlled hybrid nanowire circuit for optical logic operations including AND and OR gates. In addition, this circuit enables the on-chip photoluminescence readout of OAM-encrypted information. Our results open exciting new avenues not only for nanowire photonics to develop OAM-controlled optical switches, logic gates, and modulators but also for OAM photonics to build ultracompact photonic circuits for information processing.

Synthesis of metal free organic dyes: Experimental and theoretical approach to sensitize one-dimensional cadmium sulphide nanowires for solar cell application

Synthesis of metal-free organic dyes PDR and PDP based on the phenothiazine core unit have been attempted through solution chemistry approach and anchored on to one dimensional cadmium sulphide nanowires (CdS NWs) to be used as light harvesters in dye sensitized solar cell (DSSC) device application. Simple and cost effective solution chemistry approach leads to enable CdS NWs interconnected nano network. Synthesized dyes have been investigated through optical and electrochemical studies in addition to theoretical calculations using density functional theory (DFT). Dye anchored CdS films cover wider light absorption than bare CdS in the visible part of solar spectrum. The complete device configuration has been assembled as FTO/CdS compact/CdS NWs/Organic dye/electrolyte/Platinum electrode. PDR and PDP sensitized CdS NWs yield 0.24 and 0.28% efficiency which are 2.36 and 2.77 times as compared to bare CdS NWs (0.10%) with sun light of standard conditions of illuminations. External quantum efficiency enhancement is well supported with the obtained results and correlated well with the absorption studies. The present work successfully demonstrates the use of novel synthesized organic dyes as light harvesters.

Scaling-up photocatalytic activity of CdS from nanorods to nanowires for the MB degradation

The development of a scalable and facile method for the synthesis of visible light driven photocatalytic materials to degrade toxic organic dyes is highly challenging and essential. In this regards, cadmium sulfide (CdS) nanorods and nanowires with controlled aspect ratio, grain size, surface area, and bandgap were synthesized by a simple solvothermal method, and their photocatalytic performances were exploited for the photo-degradation of methylene blue (MB) under simulated solar light. Extensive structural characterizations to identify the origin of the activities were performed. The photocatalytic activity measurements showed that the degradation of MB was 94.41%, 97.24%, 97.88%, and 99.82% for CdS prepared by following four different synthesis routes and increasing trend showed a correlation with the nanostructure morphology changing from nanorod and nanowires with increasing aspect ratio. It has been found that CdS nanowires show more pronounced photocatalytic activity due to the efficient separation of photo-generated electron-hole pairs induced by increased the aspect ratio and higher active surface area.

Heterogeneous Bimetallic Mo‐NiPx/NiSy as a Highly Efficient Electrocatalyst for Robust Overall Water Splitting

AbstractHighly efficient electrocatalysts composed of earth‐abundant elements are desired for water‐splitting to produce clean and renewable chemical fuel. Herein, a heteroatomic‐doped multi‐phase Mo‐doped nickel phosphide/nickel sulfide (Mo‐NiPx/NiSy) nanowire electrocatalyst is designed by a successive phosphorization and sulfuration method for boosting overall water splitting (both oxygen and hydrogen evolution reactions (HER)) in alkaline solution. As expected, the Mo‐NiPx/NiSy electrode possesses low overpotentials both at low and high current densities in HER, while the Mo‐NiPx/NiSy heterostructure exhibits high active performance with ultra‐low overpotentials of 137, 182, and 250 mV at the current density of 10, 100, and 400 mA cm−2 in 1 m KOH solution, respectively, in oxygen evolution reaction. In particular, the as‐prepared Mo‐NiPx/NiSy electrodes exhibit remarkable full water splitting performance at both low and high current densities of 10, 100, and 400 mA cm−2 with 1.42, 1.70, and 2.36 V, respectively, which is comparable to commercial electrolysis.

Self-assembly of antimony sulfide nanowires on three-dimensional reduced GO with superior electrochemical lithium storage performances

The three-dimensional Sb2S3 nanowires/reduced graphene oxide (SBSWs/rGO) was prepared as an anode for lithium storage by self-assembling SBSWs on 3D rGO framework. SBSWs/rGO shows the perfect rate capability (505 mAh g−1 at 3 A g−1) and long cycle stability (697 mAh g−1 after 100 cycles at 100 mA g−1). The 3D rGO framework has good structural stability, which can provide a free space towards shortening lithium ions diffusion paths and accommodating the volume change of SBSWs. The rGO sheets with high electrical conductivity promote electron transfer in composites to improve rate performances.

Electrocatalytic water splitting with unprecedentedly low overpotentials by nickel sulfide nanowires stuffed into carbon nitride scabbards

The unprecedentedly low overpotential of 32 mV for oxygen evolution was attained by forming a unique motif of NiSx nanowires stuffed into C3N4 scabbards. With this system, electrocatalytic water splitting was demonstrated at the lowest overall overpotential of 72 mV.

Synthesis and characterization of ultralong copper sulfide nanowires and their electrical properties

We report the synthesis of novel ultralong core–shell Cu2−xS nanowires (NWs). The NWs present high flexibility, stability to acids and oxidants and low resistivity (6.9 × 10−6 Ω m). They also exhibit promising performances as supercapacitors.

Facile synthesis of Zn-doped CdS nanowires with efficient photocatalytic performance

ABSTRACT In this study, one-dimensional zinc (Zn)-doped cadmium sulphide (CdS) nanowires were synthesised by a solvothermal method. The Zn doping concentrations were varied from 1 to 5 mol% (Zn x Cd1− x S where x = 0.001, 0.003 and 0.005). As-prepared materials were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and UV–visible spectroscopy. Electrochemical impedance spectroscopy (EIS) was conducted to measure the charge transfer resistance. The photocatalytic performance of prepared materials was evaluated by the photodegradation of methylene blue (MB) dye. The result showed that 5% Zn-doped CdS is more photoactive as compared to other corresponding doped and undoped CdS. The increase in photocatalytic performance is due to improvement in the charge separation.