Incorporation Of Zn Research Articles

Characterisation of Zinc-bearing sulphate phases formed during the synthesis of phosphoric acid and Zinc removal by the ligands of Opuntia ficus-indica

ABSTRACT Phosphogypsum (PG) is a solid waste generated from phosphate fertilisers industries. It represents a serious threat to the aquatic and terrestrial environment because of its acidity and its high content in heavy metals and radionuclides. The aim of this work is to describe the formation of PG during the synthesis of the phosphoric acid, the entrapment of Zinc (Zn) in PG and its lixiviation in presence of a natural organic matter extracted as powder from the cladodes of Opuntia ficus-indica (OFI) using physical and chemical characterisation techniques such as FTIR, XRD, SEM-EDX, laser diffraction, and AAS. The formation of PG mainly occurs in the pH range between 4.6 and 3 and it accompanies the transformation of H2(PO4)− into phosphoric acid H3PO4. The maximal Zn incorporation within the PG was reached at pH 6 and decreased progressively with pH. Zinc was found to have a great tendency to migrate from PG particles to OFI’s suspensions since a maximum Zn removal percentage of 93% was achieved.

Zn-Containing Membranes for Guided Bone Regeneration in Dentistry.

Barrier membranes are employed in guided bone regeneration (GBR) to facilitate bone in-growth. A bioactive and biomimetic Zn-doped membrane with the ability to participate in bone healing and regeneration is necessary. The aim of the present study is to state the effect of doping the membranes for GBR with zinc compounds in the improvement of bone regeneration. A literature search was conducted using electronic databases, such as PubMed, MEDLINE, DIMDI, Embase, Scopus and Web of Science. A narrative exploratory review was undertaken, focusing on the antibacterial effects, physicochemical and biological properties of Zn-loaded membranes. Bioactivity, bone formation and cytotoxicity were analyzed. Microstructure and mechanical properties of these membranes were also determined. Zn-doped membranes have inhibited in vivo and in vitro bacterial colonization. Zn-alloy and Zn-doped membranes attained good biocompatibility and were found to be non-toxic to cells. The Zn-doped matrices showed feasible mechanical properties, such as flexibility, strength, complex modulus and tan delta. Zn incorporation in polymeric membranes provided the highest regenerative efficiency for bone healing in experimental animals, potentiating osteogenesis, angiogenesis, biological activity and a balanced remodeling. Zn-loaded membranes doped with SiO2 nanoparticles have performed as bioactive modulators provoking an M2 macrophage increase and are a potential biomaterial for promoting bone repair. Zn-doped membranes have promoted pro-healing phenotypes.

Comprehensive in vitro studies of novel sol gel-derived Zr4+/Zn2+ co-substituted bioactive glass with enhanced biological properties for bone healing

The synergetic osteogenic effects of zirconium (Zr) and zinc (Zn) along with bioactive glasses (BGs) have been proposed for bone implantation. We incorporated Zn into Zr-modified 58S-BG (Zr content: 5 mol. %) and characterized the structural, morphological, biological, and antibacterial properties of the proposed composite using various methods. Energy-dispersive X-ray spectroscopy analysis showed the calcium to phosphate ratio of ~1.68, after one week of conditioning in SBF. Biological assays also revealed a higher stimulating effect of the biomaterial composite on the proliferation and osteogenic response of osteoblast-like cells compared to only BGs. Antibacterial studies showed ~ 5-10% reduction in resistivity of methicillin-resistant Staphylococcus Aureus (MRSA) bacteria against the biomaterial composite in comparison to the control specimen. The incorporation of Zn led to potential outlooks for implantations instead of Zn-free specimens since they promoted the cell proliferation of MC3T3 cells as well as resistivity toward MRSA bacteria.

Free-Standing N-Doped Porous Carbon Fiber Membrane Derived From Zn-MOF-74: Synthesis and Application as Anode for Sodium-Ion Battery With an Excellent Performance.

It is important to develop new energy storage and conversion technology to mitigate the energy crisis for the sustainable development of human society. In this study, free-standing porous nitrogen-doped carbon fiber (PN-CF) membranes were obtained from the pyrolysis of Zn–MOF-74/polyacrylonitrile (PAN) composite fibers, which were fabricated in situ by an electrospinning technology. The resulting free-standing fibers can be cut into membrane disks and directly used as an anode electrode without the addition of any binder or additive. The PN-CFs showed great reversible capacities of 210 mAh g−1 at a current density of 0.05 A g−1 and excellent cyclic stability of 170.5 mAh g−1 at a current density of 0.2 A g−1 after 600 cycles in sodium ion batteries (SIBs). The improved electrochemical performance of PN-CFs can be attributed to the rich porous structure derived by the incorporation of Zn–MOF-74 and nitrogen doping to promote sodium ion transportation.

Construction of dual ligand Ti-based MOFs with enhanced photocatalytic CO2 reduction performance

As a typical titanium based MOF, NH2-MIL-125(Ti) has been widely used as catalyst for photocatalytic CO2 reduction due to its abundant photoactive sites, large surface area and high porosity. However, the CO2 conversion efficiency of NH2-MIL-125(Ti) is still limited due to its weak electron transfer ability. Herein, Zn(II)-porphyrin is selected as photosensitizer to directly coordinate with titanium oxo clusters to endow NH2-MIL-125(Ti) with a second efficient photoexcitation path to enhance the photocurrent intensity and CO2 adsorption ability, which realizes 11-fold enhancement in the CO2/CO conversion efficiency. It is found that the optimized band structure of the dual ligand Ti-based MOFs (D-TiMOF) after the incorporation of Zn(II)-porphyrin contributes a lot for the enhanced photoelectric conversion ability and CO2 adsorption ability. This research sheds light on designing efficient CO2/CO conversion MOFs based photocatalyst via porphyrin-metal oxo clusters coordination.

B-Cu-Zn Gas Diffusion Electrodes for CO2 Electroreduction to C2+ Products at High Current Densities.

Electroreduction of CO2 to multi‐carbon products has attracted considerable attention as it provides an avenue to high‐density renewable energy storage. However, the selectivity and stability under high current densities are rarely reported. Herein, B‐doped Cu (B‐Cu) and B‐Cu‐Zn gas diffusion electrodes (GDE) were developed for highly selective and stable CO2 conversion to C2+ products at industrially relevant current densities. The B‐Cu GDE exhibited a high Faradaic efficiency of 79 % for C2+ products formation at a current density of −200 mA cm−2 and a potential of −0.45 V vs. RHE. The long‐term stability for C2+ formation was substantially improved by incorporating an optimal amount of Zn. Operando Raman spectra confirm the retained Cu+ species under CO2 reduction conditions and the lower overpotential for *OCO formation upon incorporation of Zn, which lead to the excellent conversion of CO2 to C2+ products on B‐Cu‐Zn GDEs.

Polyaniline/graphene oxide/Zn-doped TiO2 nanocomposite coatings for the corrosion protection of carbon steel

This paper reports the synthesis of Polyaniline nanocomposites (PANI NCs) in the presence of graphene oxide (GO) and Zn-doped TiO2 nanoparticles by an in situ chemical polymerization method. The structure and morphology of the nanocomposites were analyzed by X-ray diffraction, Fourier transformed infrared spectroscopy, energy-dispersive X-ray analysis, field emission scanning electron microscopy and transmission electron microscopy. The corrosion resistance properties of PANI NCs were studied in 3.5% NaCl using electrochemical impedance spectroscopy and potentiodynamic polarization measurements. The coatings incorporated with PANI/GO/Zn-doped TiO2 NCs showed excellent corrosion resistance compared to those containing PANI/Zn-doped TiO2 and pure PANI. The corrosion current density decreased from 2.19 × 10−6 A cm−2 for the steel coated with butvar alone to 3.30 × 10−12 A cm−2 for the carbon steel coated with PANI/Zn-doped TiO2 NCs and to 4.32 × 10−14 A cm−2 for the carbon steel coated with PANI/GO/Zn-doped TiO2. The Tafel analysis shows that the corrosion rate of the carbon steel coated with PANI/GO/Zn-doped TiO2 NCs is lower compared to the coatings incorporated with PANI/Zn-doped TiO2 NCs and PANI, respectively. The EIS results show that the log |Z| value for the coatings prepared with PANI/Zn-doped TiO2 NCs and PANI/GO/Zn-doped TiO2 NCs is approximately 7.15 and 9.01, respectively, after 30 days of immersion in 3.5% NaCl solution. The excellent corrosion resistance properties of these coatings are likely due to the barrier effects, redox properties of PANI and increased surface area for the liberation of dopant with the incorporation of GO and Zn- doped TiO2 NPs.

Bio-BTX production from the shape selective catalytic fast pyrolysis of lignin using different zeolite catalysts: Relevance between the chemical structure and the yield of bio-BTX

As the most abundant aromatic bio-polymer in nature, lignin can be converted into bio-BTX via the shape selective catalytic fast pyrolysis process (SS-CFP). In this work, three types of MWL were isolated from softwood (Chinese fir), hardwood (poplar), and herbaceous biomass (corn stover), namely CF-MML, P-MWL, and CS-MWL. The chemical structural of lignin was analyzed by gel permeation chromatography (GPC), 2D-HSQC-NMR, and 31P NMR. Five types of the parent zeolites (HZSM-5 (25), HZSM-5 (85), Al-MCM-41, HY, and USY) and the Zn modified HZSM-5 (25) with different loading amounts (1% to 4%) were screened. Results showed that CF-MWL had the highest carbon content (59.90%). P-MWL had highest content of β-O-4 linkage (53.90%) and Mw (2778 g/mol). Among the five parent zeolites, HZSM-5 (25) was the most effective catalyst to produce bio-BTX with the highest selective yield of 56.56% at the optimal operation parameters. As a bi-functional catalyst, the incorporation of Zn on zeolite promoted the formation of BTX, where metal promoted the reaction rates of de‑oxygenation reaction and aromatization reaction, while the HZSM-5 remains the ability of shape selectivity. The maximum selective yields of BTX were 65.02% (CF-MWL) > 63.77% (CS-MWL) > 63.41% (P-MWL) when the Zn loading amount was 2%.

Metal-Loaded Mesoporous MCM-41 for the Catalytic Wet Peroxide Oxidation (CWPO) of Acetaminophen

MCM-41 based catalysts (molar ratio Si/Al = 40) were prepared by a hydrothermal route, modified by ionic exchange with different metals (Cu, Cr, Fe and Zn) and finally calcined at 550 °C. The catalysts were fully characterized by different techniques that confirmed the formation of oxides of the different metals on the surfaces of all materials. Low-angle X-ray diffraction (XRD) analyses showed that calcination resulted in the incorporation of metallic Zn, Fe and Cr in the framework of MCM-41, while in the case of Cu, thin layers of CuO were formed on the surface of MCM-41. The solids obtained were tested in the catalytic wet peroxide oxidation (CWPO) of acetaminophen at different temperatures (25–55 °C). The activity followed the order: Cr/MCM-41 ≥ Fe/MCM-41 > Cu/MCM-41 > Zn/MCM-41. The increase of the reaction temperature improved the performance and activity of Cr/MCM-41 and Fe/MCM-41 catalysts, which achieved complete conversion of acetaminophen in short reaction times (15 min in the case of Cr/MCM-41). Fe/MCM-41 and Cr/MCM-41 were submitted to long-term experiments, being the Fe/MCM-41 catalyst the most stable with a very low metal leaching. The leaching results were better than those previously reported in the literature, confirming the high stability of Fe/MCM-41 catalysts synthesized in this study.

Tuning the Mechanical and Dielectric Properties of Zinc Incorporated Hydroxyapatite

Background: Hydroxyapatite is similar to bone mineral in chemical composition and has good biocompatibility with host tissue and bone. Objective: This work aims to tailor the mechanical and dielectric properties of hydroxyapatite with zinc substitution, to improve the wearability of implant and accelerate the healing process. Methods: Pure and zinc incorporated hydroxyapatite Ca10(PO4)6(OH)2 samples have been successfully prepared by means of the chemical precipitation method. Results: The results showed that hydroxyapatite(Hap) having a hexagonal structure was the major phase identified in all the samples. It was found that the secondary phase of β-tricalcium phosphate (β-TCP) formed due to the addition of zinc, resulting in biphasic structure BCP (Hap + β-TCP). A minor phase of ZnO also formed for a higher concentration of Zn (Zn ≥ 2mol%) doping. It was found that the Zn incorporation to Hap enhanced both mechanical and dielectric properties without altering the bioactive properties. The microhardness increased up to 0.87 GPa for Zn concentration equal to 1.5mol%, which is comparable to the human bone ~0.3 - 0.9 GPa. The dielectric properties evaluated in the study showed that 1.5 mol% Zn doped hydroxyapatite had the highest dielectric constant. Higher values of dielectric constant at low frequencies signify its importance in healing processes and bone growth due to polarization of the material under the influence of the electric field. Conclusion: Sample Z1.5, having 1.5 mol% Zn doping, showed the most optimized properties suitable for bone regeneration applications.

Structural, photoluminescence, antibacterial and biocompatibility features of zinc incorporated hydroxyapatite nanocomposites

The development of bone-implant materials with enhanced bioactivity and biocompatibility has become important in the field of orthopedics. This preparation of nanocomposites of pure Hydroxyapatite (HAp) nanopowder, Hydroxyapatite-Zinc (HAp-Zn), Hydroxyapatite-reduced Graphene oxide (HAp-rGO) and Hydroxyapatite-Zinc-reduced Graphene Oxide (Hap-Zn-rGO) were accomplished using the sol–gel method. The effect of Zn and rGO on the structural, morphological, optical, antimicrobial property and biocompatibility of hydroxyapatite nanopowders are studied. The structural characterization analysed through XRD. The pure HAp and HAp-rGO exhibited hexagonal structure and incorporation of Zn in the host lattice changed this structure into orthorhombic. The average crystallite size ranges from 37 to 51 nm for various nanocomposites. The incorporation of rGO and Zn ions decreased the overall crystallite size. The presence of functional groups in the samples is analyzed and confirmed using FTIR analysis. The SEM photos revealed the structures and morphology of the nanoparticles. The chemical compositions are investigated using Energy Dispersive X-ray analysis (EDX), and all the ratios are in good agreement with the stoichiometry ratio. The photoluminescence emission peaks received around 468 nm and 385 nm and the reasons are discussed in terms of oxygen vacancies and some electronic transition between states. The optical band gap values were redshifted due to the incorporation of rGO with HAp. The in vitro antibacterial activities and biocompatibility of the synthesized pure hydroxyapatite and HAp-Zn-rGO nanocomposite are investigated using Kirby-Bauer antibacterial testing and MTT assay, respectively. The results show that zinc incorporated hydroxyapatite nanocomposites are more toxic against all bacterial strains and did not show any toxicity against living tissues.

Scalable synthesis of Cu\u2013Sb\u2013S phases from reactive melts of metal xanthates and effect of cationic manipulation on structural and optical properties

We report a simple, economical and low temperature route for phase-pure synthesis of two distinct phases of Cu–Sb–S, chalcostibite (CuSbS2) and tetrahedrite (Cu12Sb4S13) nanostructures. Both compounds were prepared by the decomposition of a mixture of bis(O-ethylxanthato)copper(II) and tris(O-ethylxanthato)antimony(III), without the use of solvent or capping ligands. By tuning the molar ratio of copper and antimony xanthates, single-phases of either chalcostibite or tetrahedrite were obtained. The tetrahedrite phase exists in a cubic structure, where the Cu and Sb atoms are present in different coordination environments, and tuning of band gap energy was investigated by the incorporation of multivalent cationic dopants, i.e. by the formation of Zn-doped tetrahedrites Cu12−xZnxSb4S13 (x = 0.25, 0.5, 0.75, 1, 1.2 and 1.5) and the Bi-doped tetrahedrites Cu12Sb4−xBixS13 (x = 0.08, 0.15, 0.25, 0.32, 0.4 and 0.5). Powder X-ray diffraction (p-XRD) confirms single-phase of cubic tetrahedrite structures for both of the doped series. The only exception was for Cu12Sb4−xBixS13 with x = 0.5, which showed a secondary phase, implying that this value is above the solubility limit of Bi in Cu12Sb4S13 (12%). A linear increase in the lattice parameter a in both Zn- and Bi-doped tetrahedrite samples was observed with increasing dopant concentration. The estimated elemental compositions from EDX data are in line with the stoichiometric ratio expected for the compounds formed. The morphologies of samples were investigated using SEM and TEM, revealing the formation of smaller particle sizes upon incorporation of Zn. Incorporation of Zn or Bi into Cu12Sb4S13 led to an increase in band gap energy. The estimated band gap energies of Cu12−xZnxSb4S13 films ranges from 1.49 to 1.6 eV, while the band gaps of Cu12Sb4−xBixS13 films increases from 1.49 to 1.72 eV with increasing x.

One-step chemical bath co-precipitation method to prepare high hydrogen-producing active ZnxCd1-xS solid solution with adjustable band structure

A series of ZnxCd1−xS solid solutions were synthesized through a simple one-step chemical bath co-precipitation route. The microstructure, morphology, composition and optical properties had been thoroughly investigated. The results showed that the as-obtained ZnxCd1−xS samples exhibited monodisperse spherical feature. These monodisperse ZnxCd1−xS spheres were composed of a large number of 5–10 nm crystal grains. The chemical composition of the ZnxCd1−xS solid solutions can be controlled by adjusting the ratio of Zn source to Cd source and the dosage of ammonia solution. Meanwhile, the energy band structure and photocatalytic properties can be optimized. The photocatalysis experiment results revealed that the as-synthesized Zn0.30Cd0.70S sample exhibited optimum water splitting performance. The satisfactory hydrogen evolution rate (HER) of Zn0.30Cd0.70S reached 27.004 mmol g−1 h−1 even without any cocatalysts, which was more than 48 times that of pure CdS (0.561 mmol g−1 h−1). This enhancing effect can owe to the balance between light absorption capacity and redox potential caused by the incorporation of Zn in the ZnxCd1−xS solid solutions.

Influence of ZnO addition and milling process on structure and conductivity of BaCe0.2Zr0.7Y0.1O3-δ ceramics

Precursor powders for BaCe0.2Zr0.7Y0.1O3-?(BCZY27) ceramics were synthesized by a modified Pechinimethod and calcined at 900?C for 12 h. The calcined BCZY27 powders were milled in eccentric and in high energy mill with the addition of 2 and 4mol% ZnO as sintering aid. The effects of milling and sintering aids on the sinterability and electrical conductivity were studied. The linear shrinkage in thermomechanical analyses started at 1050?C for the BCZY27 with 4mol% ZnO processed in eccentric mill. Theoretical density above of 90%TD was obtained for the BCZY27 milled with 4mol% ZnO and sintered at 1400?C for 4h. X-ray diffraction analysis of the BCZY27 ceramics sintered at 1400?C confirmed the presence of BaCe0.2Zr0.7Y0.1O3-? and Y0.4Ce0.6O1.8 phases. The incorporation of Zn into perovskite lattice leads to the secondary phase formation. SEM and EDS analyses confirmed the presence of Y0.4Ce0.6O1.8 phase. The sintering was assisted by BaO-ZnO eutectic, which was reflected by the increase of activation energy values for grain boundary conduction. The milling processing did not affect the conductivity properties. The obtained BCZY27 dense sample has conductivity of 7.60 ? 10?3 S/cm at 500?C.

Monitoring of metal phytofiltration performance by micro-XRF methodology.

In this work, micro-XRF was considered as a possible technique for monitoring the rate of incorporation of Cu and Zn into aquatic plants of a laboratory-scale phytofiltration system. This system employed Salvinia biloba Raddi under controlled conditions of light and nutrients. This aquatic plant is being considered as an efficient hyperaccumulator of Cu and Zn and is widely spread in South American lakes and rivers. One set of plants was exposed to 40 ppm w/w of Cu and another to 40 ppm w/w of Zn. The analytical procedure was based on the periodic in vivo quantitative analysis of Cu and Zn at selected points in the plants using micro-XRF. The accuracy of this quantification was effectively improved with the assistance of the Monte Carlo XMI-MSIM simulation code. In order to establish the input parameters of this software, careful measurements of the experimental parameters necessary for the correct modeling of the micro-XRF spectrometer were performed. After that, specially manufactured standards made of tissue equivalent material were employed to validate the configuration of the simulation code and input parameters. It was fulfilled by the comparison of measured and simulated micro-XRF spectra of these standards. Once the configuration code and input parameters were verified, two strategies were considered for the application of Monte Carlo simulation for elemental quantification in plants: an iterative process and inverse method established with external virtual standards. Benefits and drawbacks of both approaches to improve the monitoring of phytofiltration systems were carefully discussed.

Bioactive zinc-doped sol-gel coating modulates protein adsorption patterns and in vitro cell responses

Zinc is an essential element with an important role in stimulating the osteogenesis and mineralization and suppressing osteoclast differentiation. In this study, new bioactive ZnCl2-doped sol-gel materials were designed to be applied as coatings onto titanium. The biomaterials were physicochemically characterized and the cellular responses evaluated in vitro using MC3T3-E1 osteoblasts and RAW264.7 macrophages. The effect of Zn on the adsorption of human serum proteins onto the material surface was evaluated through nLC-MS/MS. The incorporation of Zn did not affect the crosslinking of the sol-gel network. A controlled Zn2+ release was obtained, reaching values below 10 ppm after 21 days. The materials were no cytotoxic and lead to increased gene expression of ALP, TGF-β, and RUNX2 in the osteoblasts. In macrophages, an increase of IL-1β, TGF-β, and IL-4 gene expression was accompanied by a reduced TNF-α liberation. Proteomic results showed changes in the adsorption patterns of proteins associated with immunological, coagulative, and regenerative functions, in a Zn dose-dependent manner. The variations in protein adsorption might lead to the downregulation of the NF-κB pathway, thus explain the observed biological effects of Zn incorporation into biomaterials. Overall, these coatings demonstrated their potential to promote bone tissue regeneration.

Microwave-Assisted Preparation of Zinc-Doped β-Tricalcium Phosphate for Orthopedic Applications

A novel two-step methodology delivering zinc into the structure of β-tricalcium phosphate (β-TCP) has been investigated. Incorporating wet precipitation of calcium-deficient apatite [Ca9-xZnx(HPO4)(PO4)5(OH)] (x = 0.00–1.00 mol) using a microwave-assisted process followed by two-hour calcination at 1000 °C has been conducted to generate a ratio of 1.48 of Zn doped β-TCP. The products were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectrometer, and field emission scanning electron microscope (FESEM). Our results confirmed that the product was crystalline Zn2+-doped β-tricalcium phosphate. The incorporation of Zn+2 into the β-TCP lattice resulted in a shifting of diffraction peaks to higher 2θ values, which were attributed to the substitution of larger-sized Ca+2 ions with smaller-sized Zn2+ ions. A reduction in the intensity of the XRD peaks was also observed due to the reduction in the degree of crystallinity of the samples. Lattice parameters along the a and c-axis showed a gradual decrease in length with an increase in the amount of Zn2+ doping. This decrease was attributed to the replacement of Ca+2 ion by the smaller-sized Zn2+ ions. The microstructure of the powders consisted of microscale aggregates fused together. EDX analysis of all samples showed that the Zn2+ doping had successfully taken place and the amount of Zn2+ present in the samples was in good agreement with the theoretical values.

Thermally grown Zn-doped hematite (α-Fe2O3) nanostructures for efficient adsorption of Cr(VI) and Fenton-assisted degradation of methyl orange

This work presents a facile method of growing zinc-doped α-hematite (Zn-doped α-Fe2O3) nanostructures via thermal oxidation of Fe sheet in the presence of Zn2+ mist. Both undoped and Zn-doped α-Fe2O3 nanostructures exhibit blade-like morphology mixed with some nanowires. In general, smaller yet denser nanostructures are formed at higher oxidation temperatures. On the other hand, misting (water vapor) enhances the oxidation rate, leading to larger nanoblades. Raman and energy dispersive X-ray spectroscopy reveal the successful incorporation of Zn in the α-Fe2O3 lattice. However, excessive Zn2+ (0.01 M) promotes the formation of large Zn hydroxide chloride particles on top of the α-Fe2O3 nanoblades. The undoped α-Fe2O3 nanostructures prepared at 650 °C in water vapor effectively adsorb hexavalent chromium [Cr(VI)] in aqueous solution with about 95% removal efficiency. The sample oxidized in 0.005 M Zn2+ mist is also efficient in the Fenton-assisted photodegradation of methyl orange with > 90% removal even after five degradation cycles.

Evaluation of Cd1–x Zn x S as electron transport layer in superstrate and inverted configurations of Sb2Se3 solar cells with n-i-p structure

In this work, we evaluate the role of the ternary compound, Cd1–x Zn x S, as an electron-transport layer (ETL) in the n-i-p structure of antimony selenide (Sb2Se3) solar cells. The incorporation of Zn reduces the amount of Cd and contributes to improving the power-conversion efficiency of the solar cell. On the other hand, the n-i-p structure makes it possible to overcome two issues that impair the efficiency of Sb2Se3 solar cells: the potential barrier due to the rear contact and the low hole concentration in the Sb2Se3 absorber material. In this paper, we present a theoretical work on Sb2Se3 solar cells using the SCAPS 1-D software. The theoretical analysis allows us to understand the impact of the semiconductor parameters on efficiency and also to find the optimal values for an optimized device. The optimal molar composition of the ternary compound is investigated in the superstrate and inverted configurations. Parameters such as the thickness, defect density, and the acceptor concentration of the Cd1–x Zn x S and Sb2Se3 layers are optimized. Also, we analyze the impact of interface-defect density at the hole-transport layer (HTL) (Sb2Se3) and the ETL (Sb2Se3). Following optimization, a power-conversion efficiency (η) of 14.29% is obtained using Cd0.4Zn0.6S as the ETL and Cu2O as the HTL in the superstrate configuration. This simulation process is expected to guide other experimentalists in the design and manufacture of solar cells.

Effect of Zinc Addition on Electrodeposition of Fe-W Alloys

Tungsten (W) and its alloys have been applied to various industrial fields for its excellent mechanical, tribological and chemical properties. Electrodeposition process is anticipated to be a economical and cost-effective method for preparing W-based alloys since W has the highest melting point among metals (3422 ℃). In general, electrodeposition of metal W from aqueous solution is difficult because it exists as oxyanions in a wide pH range. However, electrodeposition in the co-existence of iron group metals such as iron (Fe), nickel (Ni), and cobalt (Co), enables W to be reduced to metal state, which is so called the induced co-deposition. Recently, electrodeposited W alloys have gained increased attention due to their advanced properties such as high microhardness, thermal stability, wear resistance and corrosion resistance. Among them, binary Fe-W, Ni-W alloys have been most intensively studied. These alloys are expected to be promising substitute for hard chrome (Cr) plating due to its high hardness, abrasion resistance, heat resistance and corrosion resistance without the use of hazardous hexavalent chromium (Cr6+). Meanwhile, Ni has been reported as the one of the major elements in triggering skin allergies for humans. Therefore, we focused on Fe-W-based alloys that do not use Ni. Unfortunately, Fe-W alloys are reported to have inferior mechanical properties and corrosion resistance compared to Ni-W alloys. Thus, the addition of Zinc (Zn); an element that is widely used in anti-corrosion coatings, as a third element to the Fe-W binary alloy was considered for preparation of a ternary alloy with improved properties.This study reports the first experimental results of electrodeposition of ternary Fe-W-Zn alloy by incorporation of Zn to Fe-W alloys. Ternary Fe-W-Zn plating was prepared in citrate-ammonia aqueous solution heated to 80℃ by potentiostatic elcecrolysis range from -1.1 to -1.4V (vs. Ag/AgCl). Ternary alloys with the compositions of Fe-(28.8 to 37.1 at.%) W-(1.7 to 6.5 at.%) Zn were obtained with maximum current efficiency of 42%. The corrosion properties of the prepared ternary alloys were compared with those of Ni-W and Fe-W platings by a potentiodynamic polarization test in deaerated 1M sulfuric acid solution and 3 mass% sodium chloride solution. Although Zn has lower potential than Fe, ternary Fe-W-Zn alloys with relatively low Zn contents of 1.7 to 2.6 at.% showed better anti-corrosion properties than Ni-20 at.%W and Fe-33 at.%W alloys in acidic media. Addition of a small amount of Zn was found to be effective in tuning properties of Fe-W alloys. Acknowledgement This work was partially supported by the JST-OPERA Program, Japan [grant number JPMJOP1843]