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Zinc (Zn) has arisen as a significant suppressor of vacancy formation in halide perovskites, establishing its pivotal role in defect engineering for these materials. Herein, the Zn‐catalyzed vapor‐liquid‐solid (VLS) route is reported to render black‐phase CsPbI3 nanowires (NWs) operationally stable at room temperature. Based on first‐principle calculations, the doped Zn2+ can not only lead to the partial crystal lattice distortion but also reduce the formation energy (absolute value) from the black phase to the yellow phase, improving the stability of the desired black‐phase CsPbI3 NWs. A series of contrast tests further confirm the stabilization effect of the Zn‐doped strategy. Besides, the polarization‐sensitive characteristics of black‐phase CsPbI3 NWs are revealed. This work highlights the importance of phase stabilization engineering for CsPbI3 NWs and their potential applications in anisotropic optoelectronics. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of Zn doping on electrical properties and conduction mechanisms of n-silicon (n-Si) diodes using current-voltage (I–V) and capacitance-voltage-frequency (C–V–f) measurements. The results revealed that Zn doping alters the I–V behaviour of the diode from a typical exponential curve to an ohmic one. Notably, Zn doping increased the reverse current by a factor of 37, while reducing the forward current by a factor of 3 at 3 V. This suggested that Zn-related defects introduced more minority carriers into the Si. The introduction of minority carriers is confirmed by a change in material conductivity-type from n-to p-type. Moreover, Zn doping reduces the full depletion voltage (FDV), meaning the diode could be fully depleted with a lower voltage. This reduction in FDV was crucial for designing highly sensitive radiation detectors. The observed changes in the diode's electrical behaviour were attributed to defects introduced by Zn into Si. Zn-doped n-Si diodes exhibited characteristics akin to radiation-resistant diodes. These findings implied that Zn may be instrumental in advancing research focused on enhancing silicon properties and developing radiation-resistant detectors for high-energy physics studies.

In this study, nano films of pure NiO and films doped with zinc and copper concertation (1%, 3%, 5%) and their mixture for 5% under 100 nm thickness were generated on glass bases using the sol-gel process at a temperature of 298 K. The Cu, Zn-doped NiO and nano NiO optical characteristics were examined throughout a wavelength range of 300 to 800 nm, with high transmittance values of 94% in the Vis-NIR. Transmittance films after doped copper and zinc have dropped to 5% (91% and 92%), respectively. The index of refraction, coefficient of extinction, optical conductivity and the dielctric constants (real and imaginary) were also studied. The results show that the optical conductivity of NiO?Zn and NiO?Cu films increased at the room temperature with increasing the dopant concentrations.

The effect of Zn-doping on the phase composition and optical properties of the Bi2ZnxFe1-xTa2O9.5-Δ (x = 0.3, 0.5, 0.7) was studied. XRD data showed that the samples crystallize in the structural type of pyrochlore (sp. gr.Fd-3m). For all the samples, an admixture of bismuth orthotantalate β-BiTaO4 triclinic modification up to 22.5 wt.% is observed. The content of β-BiTaO4 increases with zinc doping. The unit cell parameter of the pyrochlore phase rises from 10.4878 (x = 0.3) to 10.5154 Å (x = 0.7). The samples are characterized by a porous microstructure with indistinct grain boundaries. Zinc oxide has a sintering effect on ceramics. The charge state of the ions in Bi2ZnxFe1-xTa2O9.5-Δ was investigated by X-ray spectroscopy. NEXAFS and XPS data show that zinc doping does not change the oxidation degree of iron and bismuth ions in pyrochlore. The ions are in the charge states Bi(+3), Fe(+3), Zn(+2). In the Ta4fspectrum, an energy shift of the absorption band towards lower energies by ΔE = 0.5 eV is observed, which is typical for tantalum ions with an effective charge of (+5-δ). With the increase of x(Zn), the Bi 4f7/2 and Bi 4f5/2 bands are observed to shift to lower energies due to the distribution of some Zn(II) ions in the bismuth position. [ABSTRACT FROM AUTHOR]

BiFe1-xZnxO3 (BFZO) (x = 0, 2%, 4%, 6%) thin films were successfully prepared on Pt/Ti/SiO2/Si substrates by sol-gel method. The effect of Zn doping on the structure, surface morphology, leakage current density, ferroelectric and ferromagnetic properties of BiFeO3 (BFO) thin films were investigated systematically. XRD patterns show that all samples match well with the perovskite structure without impurity phase. SEM images show that BFZO thin films with x = 4% exhibit uniform fine grains and higher density, which is instrumental for the improvement of leakage current density. The leakage current density curve shows that BiFe0.96Zn0.04O3 thin films have the lowest leakage current density (J = 1. 56 x 10-6 A/cm²) under the electric field strength of 300 kV/ cm, which is three orders of magnitude lower than that of pure BFO thin films. Furthermore, BiFe0.96Zn0.04O3 thin film exhibits the largest remnant polarization (2Pr = 20. 91 μC/cm²) at room temperature, which is more than four times as large as that of pure BFO (2Pr = 4. 96 μC/cm²). Additionally, compared with BFO thin film, Zn doping also enhances the ferromagnetic properties of BFO thin films, and as Zn doping concentration increases, the saturation magnetization of BFZO thin films is significantly enhanced, which provides potential applications in information storage. [ABSTRACT FROM AUTHOR]

Several beneficial features maintain TiO 2 in the top list of viable materials for photocatalytic purposes. However, its relatively large band-gap (3.0–3.2 eV) still hampers practical applications under sunlight. This work explores Direct Current (DC) Plasma Electrolytic Oxidation (PEO) of titanium as a fast, easily-scalable and single-step tool to synthesise doped TiO 2 photoanodes with controlled morphology, crystalline structure and thickness. Zn-, Cu- and Fe-doped crystalline TiO 2 films were obtained in H 2 SO 4 aqueous solutions containing ZnSO 4 , CuSO 4 and FeSO 4 precursors, respectively. As-prepared TiO 2 films showed a porous and homogeneous sponge-like surface morphology, typical of PEO-produced oxides, and a crystalline phase structure consisting of a mixture of anatase and rutile phases. The anatase content varied in the 54–100 % range and correspondingly the band-gap energy was in the 2.85–3.07 eV range. Doped oxides prepared with a low concentration of the metal precursors showed monochromatic incident-photon-to-current-efficiency (IPCE) values exceeding those obtained with pristine TiO 2 by up to 24 %, best performing in the order Zn- > Cu- > Fe-doped TiO 2. Photocurrent under polychromatic UV-Vis irradiation showed an analogous trend and the estimated efficiency of solar-light harvesting was in the 0.3–4 % range, with Zn- ≈ Cu- > Fe-doped TiO 2. Although the superior performance of the PEO-prepared metal-doped TiO 2 could not be fully confirmed by photoelectrocatalytic oxidation tests of organics, the present investigation showed the viability of DC PEO for the synthesis of metal-doped TiO 2 photoanodes. [Display omitted] • Zn, Cu, Fe doped crystalline TiO 2 films obtained by plasma electrolytic oxidation. • Best photoeletrochemical activity at low doping levels. • IPCE and LSV values exceeding pristine TiO 2. • No straightforward correlation between photoelectrochemical and catalytic activity. [ABSTRACT FROM AUTHOR]

Undoped and zinc-doped TiO _2 nanoparticles (NPs) were synthesized by the sol–gel method. The XRD spectra revealed that both synthesized undoped and Zn-doped TiO _2 NPs remain in the anatase phase after calcined at 500 °C. The crystallite size was increased from 17 to 52 nm as the Zn content was increased from 0 to 0.2 mol%, which implies also a decrease of the micro-strain and surface area. The agglomerated spherical-like morphology with a diameter of roughly 10–20 nm was shown by SEM and TEM micrographs. The bandgap values were found to be decreased from 3.2 to 3.0 eV when Zn concentration increased from 0 to 0.2 mol%. A reduction in bandgap with an increase in dopant concentration may due to the increased in crystallite size along with enhanced lattice parameters (i.e., a and c ) and d -spacing. From PL spectra, all samples exhibited a broad emission band in the visible region of about 400–500 nm centered at 430 nm. The highest PL emission was obtained for 0.2 mol% Zn doping. The broad PL emission over the visible range is greatly reduced at 0.4 mol% Zn due to concentration quenching. It is suggested that the Zn ^2+ doping induced oxygen vacancies which could promote the photoluminescence processes.

A novel nano‐ternary spinel oxides of Zn−Ni‐Co−O are synthesized via the coprecipitation method and used for detection towards Cu(II). The Zn doping effect on morphologies and microstructures of ZnxNi1‐xCo2O4 (x=0, 0.2, 0.4, 0.6, 0.8, 1.0) is systematically characterized and investigated. At the x of 0.4, the prepared Zn0.4Ni0.6Co2O4 modified electrode nanomaterials can realize electrochemical ultratrace detection of Cu(II), which shows the lowest detection limit of 1.96 nM with a linear range of 0.1 μM∼1.0 μM and the highest sensitivity of 15.2 μA/μM. Meanwhile, Zn0.4Ni0.6Co2O4 modified electrodes exhibit excellent repeatability (relative standard deviation (RSD) of 0.34 %), reproducibility (RSD of 0.3 %), stability (RSD of 3.0 %) as well as anti‐interference analysis, which has been successfully applied in the actual water environment. These results indicate that ZnxNi1‐xCo2O4 nanoparticles as a promising modified electrode materials for the electrochemical detection Cu(II). [ABSTRACT FROM AUTHOR]

The use of lead-free piezoelectric materials in high-power applications requires a high mechanical quality factor Q m and temperature-stable ferroelectric properties. In this article, the influence of Mg-doping on the 0.94Na 1/2 Bi 1/2 TiO 3 -0.06BaTiO 3 system is analysed with focus on the role of defects related to ferroelectric hardening. Temperature stability (depolarization temperature), electromechanical properties (piezoelectric activity, Q m), electrical properties (conductivity) and crystal structure for compositions were quantified. Compositions with similar amount of Zn-doping were analyzed for reference. A drastic increase in electrical conductivity at −0.3/−0.5 mol% Mg was associated with a concomitant increase in Q m. Similar behavior in Zn-doped compositions provides a basis for a more comprehensive mechanistic understanding of acceptor doping in these lead-free piezoceramics. The very high and almost vibration-velocity-independent Q m above 800 makes Mg-doped 0.94Na 1/2 Bi 1/2 TiO 3 -0.06BaTiO 3 an excellent candidate for high-power application. [ABSTRACT FROM AUTHOR]

In this study, nano films of pure NiO and films doped with zinc and copper concertation (1%, 3%, 5%) and their mixture for 5% under 100 nm thickness were generated on glass bases using the solgel process at a temperature of 298 K. The Cu, Zn-doped NiO and nano NiO optical characteristics were examined throughout a wavelength range of 300 to 800 nm, with high transmittance values of 94% in the Vis-NIR. Transmittance films after doped copper and zinc have dropped to 5% (91% and 92%), respectively. The index of refraction, coefficient of extinction, optical conductivity and the dielctric constants (real and imaginary) were also studied. The results show that the optical conductivity of NiO-Zn and NiO-Cu films increased at the room temperature with increasing the dopant concentrations. [ABSTRACT FROM AUTHOR]

In this study, facile synthesis, characterization, and stability tests of highly luminescent Zn-doped CsPbBr3 perovskite nanocrystals (NCs) were demonstrated. The doping procedure was performed via partial replacement of PbBr2 with ZnBr2 in the precursor solution. Via Zn-doping, the photoluminescence quantum yield (PLQY) of the NCs was increased from 41.3% to 82.9%, with a blue-shifted peak at 503.7 nm and narrower spectral width of 18.7 nm which was consistent with the highly uniform size distribution of NCs observed from the TEM image. In the water-resistance stability test, the doped NCs exhibited an extended period-over four days until complete decomposition, under the harsh circumstances of hexane-ethanol-water mixing solution. The Zn-doped NC film maintained its 94% photoluminescence (PL) intensity after undergoing a heating/cooling cycle, surpassing the un-doped NC film with only 67% PL remaining. Based on our demonstrations, the in-situ Zn-doping procedure for the synthesis of CsPbBr3 NCs could be a promising strategy toward robust and PL-efficient nanomaterial to pave the way for realizing practical optoelectronic devices. [ABSTRACT FROM AUTHOR]

Photoreduction of CO2 without photosensitizers and scavengers runs into the development bottleneck for lack of excellent photocatalysts and ambiguous reduction mechanism. Herein, an ultrathin CoO layer containing Zn‐dopants and O‐vacancies (Vo‐Zn‐CoO) is designed as an archetype to explore the influence mechanism of Zn on O‐vacancies in ultrathin nanolayer for CO2 photoreduction. DFT calculations illustrate that Zn‐dopants not only reduce formation barriers of *COOH and *CO intermediates, but also form π‐back‐bonding with *CO stimulating CH4 evolution. Finally, Vo‐Zn‐CoO layer significantly enhances CO2 photoreduction efficiency and CH4 selectivity with 26.8 µmol g−1 h−1 (63.8%) compared to 7.2 µmol g−1 h−1 (23.6%) for CoO layer with O‐vacancies. Moreover, the synergistic effect of Zn and O‐vacancies benefits the stability of O‐vacancies in photocatalysts, achieving durable photocatalytic performance of Vo‐Zn‐CoO layer. This work manifests that the strategy of metal atoms synergistic O‐vacancies is effective to optimize CO2 photocatalytic efficiency, selectivity, and stability of photocatalyst with O‐vacancies. [ABSTRACT FROM AUTHOR]

A series of morphotropic phase boundary (MPB) compositions of (1–x)Na1/2Bi1/2TiO3‐xBaTiO3 (x = 0.05, 0.055, 0.06, 0.065, 0.07), with and without 0.5 mol% Zn‐doping was synthesized using the solid‐state route. The samples were characterized using X‐ray diffraction, dielectric analysis, and electromechanical measurements (piezoelectric d33 coefficient, coupling factor kp, mechanical quality factor Qm, and internal bias field Ebias). The increase in the ferroelectric‐relaxor transition temperature upon Zn‐doping was accompanied by a shift of the MPB toward the Na1/2Bi1/2TiO3‐rich side of the phase diagram. Higher tetragonal phase fraction and increased tetragonal distortion were noted for Zn‐doped (1 – x)Na1/2Bi1/2TiO3‐xBaTiO3. In addition, ferroelectric hardening and the presence of an internal bias field (Ebias) were observed for all doped compositions. The piezoelectric constant d33 and the coupling coefficient kp decreased by up to ∼30%, while a 4‐ to 6‐fold increase in Qm was observed for the doped compositions. Apart from establishing a structure–property correlation, these results highlight the chemically induced shift of the phase diagram upon doping, which is a crucial factor in material selection for optimal performance and commercialization. [ABSTRACT FROM AUTHOR]

A series of morphotropic phase boundary (MPB) compositions of (1–x)Na1/2Bi1/2TiO3‐xBaTiO3 (x = 0.05, 0.055, 0.06, 0.065, 0.07), with and without 0.5 mol% Zn‐doping was synthesized using the solid‐state route. The samples were characterized using X‐ray diffraction, dielectric analysis, and electromechanical measurements (piezoelectric d33 coefficient, coupling factor kp, mechanical quality factor Qm, and internal bias field Ebias). The increase in the ferroelectric‐relaxor transition temperature upon Zn‐doping was accompanied by a shift of the MPB toward the Na1/2Bi1/2TiO3‐rich side of the phase diagram. Higher tetragonal phase fraction and increased tetragonal distortion were noted for Zn‐doped (1 – x)Na1/2Bi1/2TiO3‐xBaTiO3. In addition, ferroelectric hardening and the presence of an internal bias field (Ebias) were observed for all doped compositions. The piezoelectric constant d33 and the coupling coefficient kp decreased by up to ∼30%, while a 4‐ to 6‐fold increase in Qm was observed for the doped compositions. Apart from establishing a structure–property correlation, these results highlight the chemically induced shift of the phase diagram upon doping, which is a crucial factor in material selection for optimal performance and commercialization. [ABSTRACT FROM AUTHOR]

• A transition metal Zn-doped CdS/CdSe QDSSCs are performed by SILAR. • The narrowed band gap caused the strong light absorbance. • The high concentration carriers promoted the shift of Fermi level towards the CB. • Zn-doping contributes to attenuation of the interfacial charge recombination rate and prolongs the electron lifetime. Metal ion doping is a suitable approach for optimizing quantum dots (QDs), which can change the recombination dynamics and charge separation of QDs via creating electronic states within their band gap, and improve their optical and electrical properties. In this work, the transition metal Zn-doped CdS and CdSe QDs are performed by SILAR (successive ionic layer adsorption and reaction) method. And the sensitized solar cells (QDSSCs) based on the Zn-doped CdS and CdSe QDs are assembled. The effect of Zn-doping concentration on the optical properties and charge carrier transport characteristics of photoanodes is investigated. Based on these QDs sensitized TiO 2 photoanodes, the assembled QDSSCs with Zn-dopant of a molar concentration of 1.6 mol % exhibited a maximum power conversion efficiency (PCE) of 5.59 %, which is increased by 26.76 % in comparison with that of the QDSSC (4.41%) without Zn-doping. The significantly enhanced PCE of QDSSCs was attributed to improved current density and open-circuit voltage, particularly arising from enhanced light absorbance by narrowing the band gap with the midgap states and upshift of Fermi level promoted by the high electrons concentration due to the ionization of Zn impurities. In addition, the Zn-doping contributes to attenuation of the interfacial charge recombination rate and prolongs the electron lifetime, resulting in more efficient charge collection in QDSSCs. [ABSTRACT FROM AUTHOR]

Molybdenum sulfide (MoS2) is considered as an alternative material for commercial platinum catalysts for electrocatalytic hydrogen evolution reaction (HER). Improving the apparent HER activity of MoS2 to a level comparable to that of Pt is an essential premise for the commercial use of MoS2. In this work, a Zn‐doping strategy is proposed to enhance the HER performance of MoS2. It is shown that tiny Zn doping into MoS2 leads to the enhancement of the electrochemical surface area, increases in proportion of HER active 1T phase in the material and formation of catalytic sites of higher intrinsic activity. These benefits result in a high‐performance HER electrocatalyst with a low overpotential of 190 mV(@10 mA cm−2) and a low Tafel slope of 58 mV dec−1. The origin for the excellent electrochemical performance of the doped MoS2 is rationalized with both experimental and theoretical investigations. [ABSTRACT FROM AUTHOR]

In this study, the crystal structure, functional groups, morphological structure, elemental compositions, antimicrobial activity, and structural changes in the SBF of Zn-based HAp samples, synthesized by sol-gel method, doped with chitosan (CTS) at different amounts, were investigated. The crystal structure of the synthesized samples was determined by XRD technique, and the functional groups of the samples were determined by FTIR spectroscopy. The elemental compositions and morphologies of the HAp samples were investigated by SEM equipped with EDX spectroscopy. It was observed that the synthesized samples had antimicrobial activity. The effect of chitosan addition and immersing in SBF affected the crystallization percentages of the samples. No significant changes were observed in the morphology. [ABSTRACT FROM AUTHOR]

In this paper, experimental method and first-principles calculations were combined to study the properties of pure hydroxyapatite and Zn-doped hydroxyapatite. Pure and Zn-doped hydroxyapatite (HA) powders were synthesized using the hydrothermal method. The FTIR spectra show that the adding of Zn atoms makes the intensity of PO43− stretching peaks become weaken and obscure. In addition, the O-H bending peaks at 3570 and 632 cm−1 become weaker and broader. The XRD patterns show that the replacement of Zn ion in the HA structure leads to the distortion in HA lattice, which is shown and proved by the TEM analysis. First-principles calculations based on density functional theory (DFT) method were applied to investigate the Zn-doped hydroxyapatite. The elastic properties of HA, HA with Ca2+(II) vacancy, and Zn doped HA systems were calculated. Through the calculation, we found that the doping of Zn atoms made the elastic modulus of HA crystal becoming soft. The elastic properties dropped dramatically when there is a vacancy in the Ca2+(II) position. Compared with the HA-VCa2+ structure, the Zn-doped HA has better elastic properties and stability. The local structure of the substitution position was presented and analyzed. In the Zn-doped HA structure, the OH− group adjacent to Zn2+ is significantly displaced from the c axis toward to the Zn2+, making the lattice distorted. The distortion of the crystal lattice is responsible for the weakness of the P-O stretching peaks and O-H bending peaks in the FTIR spectra of the Zn doped HA crystal. The softness of the elastic modulus is also caused by the distortion of the lattice and the weak bonding force between Zn atom and O atom. [ABSTRACT FROM AUTHOR]

As the cost-effective and nontoxic alternative for hydrogen evolution reaction (HER), Co 9 S 8 has attracted much attention. This paper explores the regulation of Zn doping impacted the unique nanostructure and electrocatalytic performance on Co 9 S 8. Herein, utilizing copper foam (CF) as substrate, a series of different nanostructure of (Zn-)Co 9 S 8 @CF has been synthesized by accurately varying the ratio of Zn2+ to Co2+. Compared with aggregated pure Co 9 S 8 and other different ratios contrast samples, Zn–Co 9 S 8 @CF-(1-1) with a zinc to cobalt ratio of 1 possesses highly dispersity which can be attributed to the novel nano-neuron network structure. The electrochemical measurements for HER demonstrate that Zn–Co 9 S 8 @CF-(1-1) not only reveals superior activity with small overpotentials to achieve a current density of 10 mA cm−2 in acidic (278 mV) and alkaline (273 mV) media, but also exhibits long-time durability in the solution with a wide range of pH. The excellent performance of Zn–Co 9 S 8 @CF-(1-1) can be attributed to the unique reticular structure which can facilitate exposure of numerous active sites and favorable long-term stability. The substrate of three-dimensional CF can provide the remarkable conductivity. This work provides a precise and effective approach to regulate three-dimensional nanostructure of Zn-doped electrocatalysts for HER. Image 1 • Zn–Co 9 S 8 on copper foam (CF) with a nano-neuron network structure is synthesized. • The ratios of Zn2+ to Co2+ can affect the structure of Zn–Co 9 S 8 @CF. • Zn–Co 9 S 8 @CF exhibits excellent activity and long-time durability with a wide range of pH. • Zn doping is a promising method for construct the novel structure of electrocatalysts. [ABSTRACT FROM AUTHOR]

• Uniform Zn doped mesoporous nanoparticles (Zn-MSNs) were prepared by a sol–gel method. • Composites mechanical properties were remarkably improved by incorporation of Zn-MSNs. • The antibacterial rate of the composites with 15% Zn-MSNs (1.5% of Zn) achieved 100%. The purpose of this work was to explore the enhancement effect of zinc doped mesoporous silica nanoparticles (Zn-MSNs), which could form micromechanical interlocking with resin matrix and sustainably release Zn2+, on the mechanical and antibacterial properties of the dental resin composites. Zn-MSNs were prepared by a sol–gel method, and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and N 2 adsorption/desorption. The mechanical properties of the dental composites reinforced by Zn-MSNs were measured by a universal mechanical testing machine. Antibacterial activities of dental composites were evaluated by both qualitative and quantitative analysis using Streptococcus mutans (S. mutans). The cytotoxicity of the Zn-MSNs filled dental composites was investigated by osteoblasts (OBs). The synthesized Zn-MSNs possessed good monodispersity with an average particle size of about 138 nm. The mechanical properties of the composites gradually increased with the increase of the content of Zn-MSNs. The flexural strength, flexural modulus, compressive strength and micro-hardness of the composites containing 15 wt% Zn-MSNs were 31.21%, 50.47%, 53.83% and 26.79% higher than the samples with no Zn-MSNs, respectively. The antibacterial performance was significantly improved by the addition of Zn-MSNs and the antibacterial rate of the composite with 15 wt% of Zn-MSNs reached 100%. Cytotoxicity tests revealed that all the composites were biocompatible during OBs incubation. The prepared Zn-MSNs can effectively improve the mechanical and antibacterial properties of the dental resin composites. [ABSTRACT FROM AUTHOR]

Aqueous hybrid supercapacitors (AHSCs) have emerged as a promising choice for advanced energy storage systems in the next generations. It is primarily due to their exceptional characteristics, such as superior power density, non-flammability, and environmental compatibility. However, compared to non-aqueous supercapacitors, the small working potential windows and less cycle stability are their key challenges to solve. A facile method was used to synthesize Zn-doped Cr 2 O 3 supported on carbon cloth (CC) as a binder-free electrode for AHSCs and denoted as ZnCr 2 O 4 @CC. According to the experimental findings, the ZnCr 2 O 4 @CC material possesses a rapid charge transfer. As a result, the ZnCr 2 O 4 @CC electrode showed a remarkable charge storage performance with dominant charge storage by capacitive type (68.4 % at 10 mVs−1). Further, the ZnCr 2 O 4 @CC electrode exhibits a maximum capacitance of 374 Fg−1 at 1 Ag−1 and outperforms its counterparts (194 Fg−1 for Cr 2 O 3 and 60.78 Fg−1 for ZnO). After 10,000 cycles, the ZnCr 2 O 4 @CC electrode still shows 98.1 % of its initial capacitance, demonstrating its potential for practical applications. The AHSC device also constructed using ZnCr 2 O 4 @CC as a cathode and activated carbon (AC) as an anode with 1 M KOH as an electrolyte (ZnCr 2 O 4 @CC//AC-AHSC). The AHSC device exhibits an excellent capacitance retention of 96.43 % after 10,000 cycles. Further, the AHSC shows a superb energy density of 26.2 Whkg−1 at a power density of 800.6 Wk−1 g. The current work describes a new strategy for the production of next-generation aqueous hybrid supercapacitors with exceptional electrochemical performance. [ABSTRACT FROM AUTHOR]

The development of non-noble-metal electrocatalysts with excellent performance and economic benefits toward the hydrogen evolution reaction (HER) is very vital for the development of future energy. Two-dimensional transition-metal sulfides, in particular, WS 2 based materials, are considered to be fine alternative catalysts for the HER, where doping engineering has proven to be an effective way to tune their electrocatalytic activity. Herein, we have reported different doping concentration-based Zn-doped WS 2 shows enhanced electrochemical activity compared with pure WS 2. The obtained Zn-doped WS 2 (WS 2 -30) displays excellent HER performance, having an onset potential of 180 mV at the current density of 10 mA cm−2 with a low Tafel slope of 70 mV/dec. Theoretical and experimental studies show the substantial atomic percentage of Zn in the WS 2 facilitates the cathodic reduction of oxygen via the four-electron pathway with a higher limiting-diffusion current density (−4.8 mA cm−2) and higher rate constant than bulk WS 2. Thus, to enhance the intrinsic activities of transition-metal sulfides, doping engineering provides an efficient method that may contribute to developing nonprecious electrocatalysts for HER. [Display omitted] • Zn-doped WS 2 are prepared via two step hydrothermal method. • Bulk WS 2 acts as a poor electro catalyst towards ORR and HER reaction due to inactive basal plane. • The Zn-doping enhances the surface area and active sites for H adsorption in WS 2 via Volmer- Heyrovsky mechanism. • Zn doping boosts the catalytic activity of WS 2 towards ORR via four electron transfer process rather than bulk WS 2. [ABSTRACT FROM AUTHOR]

Asymmetric supercapacitors based on aqueous and solid-state electrolytes are useful for a variety of applications. The birnessite δ-MnO 2 is one of the efficient materials from the MnO x family characterized by large interlayer distance (∼7.3 Å) and high theoretical specific capacitance (∼1370 F g −1 ). However the main concern which hinders its usage for practical applications is its low electronic conductivity (∼10 −6  S cm −1 ). There are different means to enhance the conductivity and in the present studies, two simultaneous methods viz; a method of synthesis of nano-flakes along with Zn-doping in δ-MnO 2 is implemented. A specific capacitance of ∼466 F g −1 at a current density of 0.5 A g −1 is obtained for an optimum Zn doping concentration of 1 mol% which is almost two times more than the corresponding pristine one. Both aqueous and solid-state asymmetric supercapacitor devices are fabricated using Zn doped δ-MnO 2 as electrode material which can be easily scalable to industrial level. A lab-scale demonstration prototype is constructed which essentially validated the charging of solid-state supercapacitor using battery and allowing the supercapacitor to discharge through a red-LED by means of a two-way switch. [ABSTRACT FROM AUTHOR]

• Zn sites and CDs doped in CHA zeolites. • CDs transferred photogenerated electrons from CN to Zn-CHA. • CN plays an important role in the protonation of H 2 O. • CDs@Zn-CHA/CN has higher hydrophobicity, which facilitates the adsorption of nitrogen. The construction of zeolite/semiconductor was proved to be one of the effective ways to improve the photocatalytic performance. In this paper, CDs@Zn-CHA/CN was prepared by hydrothermal method, and a synergistic interaction was formed between CDs@Zn-CHA and CN to enhance the photocatalytic nitrogen fixation activity. The photoelectric properties characterization and XPS and in situ IR results indicated that CDs, Zn-CHA and CN formed a charge transfer interface, which improved the separation of photogenerated carriers and greatly enhanced the nitrogen fixation efficiency. Nitrogen is adsorbed by Zn-CHA with microporous structure and activated by contact with Zn sites on CHA. CN has a good visible light response and provides photogenerated carriers under visible light irradiation. CDs act on the interfacial charge transfer between Zn-CHA and CN, promoting the transfer of photogenerated electrons to the nitrogen adsorbed by Zn-CHA and accelerating the dissociation of N N, thus increasing the yield of NH 3. Compared with CDs@Zn-CHA and CN, 10% CDs@Zn-CHA/CN achieved 5.82 and 2.99 times of nitrogen fixation yield, respectively. Furthermore, the higher hydrophobicity of CDs@Zn-CHA/CN was found by contact angle measurement, which provided more abundant three-phase contact points for the reaction process. This study provides new ideas and directions for the design of photocatalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Objective(s): This paper describes synthesizing of magnetic nanocomposite with co-precipitation method. Materials and Methods: Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe 3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy. Results: results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of “particles size” and “exchange interactions”. Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe 3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV. Conclusion: these magnetic nanocomposite structures since having superparamagnetic property offer a high potential for biosensing and biomedical application.

Zn-doped hydroxyapatite/graphene (Zn-doped HA/GP) composite was successfully in situ synthesized by one-pot hydrothermal treatment for the first time, and was studied through experimental analysis and density functional theory calculations. The effects of a series of Zn contents (0mol%, 1mol%, 5mol%, 10mol% and 20mol%) on the HA crystal structure, the morphology and composition of composites were also investigated. The obtained doped composites were analyzed and characterized by the techniques of field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray detector (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and Raman spectroscopy. Density functional theory calculations of Zn-doped HA showed that the replacement of Zn ions in HA crystal lattice could cause the OH − group to move off the c axis toward the Zn ions and become closer to the PO 4 3− group, resulting in the formation of hydrogen-bond between OH − and PO 4 3− groups. The morphology of Zn-doped HA/GP composite showed that Zn-doped HA grains with molar fraction of 1 mol% Zn are intimately attached on the surface of graphene whereas the amounts of Zn-doped HA attached on the GP surface reduce obviously and the interfacial interactions are weakened accordingly as the Zn doping amount increased from 5 to 20 mol%, which indicates that the low crystallinity of Zn-doped HA particles due to an increasing Zn content may have a negative effect on interfacial interaction between Zn-doped HA and GP. [ABSTRACT FROM AUTHOR]

In the quest of promising Indium free amorphous transparent conducting oxide (TCO), Zn-doped SnO 2 /Ag/Zn-doped SnO 2 (OMO) multilayer films were prepared on flexible polyethylene terephthalate (PET) substrates by RF sputtering at room temperature (RT). Growth parameters were optimized by varying sputtering power and working pressure, to have high electrical conductivity and optical transmittance. Optimization of the thickness of each layer was done by Essential Macleod Program (EMP) simulation to get the higher transmission through OMO multilayer. The sheet resistance and transmittance of 3 at% Zn-doped SnO 2 thin film (30 nm) were 2.23 kΩ/□, (ρ ~ 8.92×10 −3 Ω∙cm) and 81.3% (at λ ~ 550 nm), respectively. By using optimized thicknesses of Zn-doped SnO 2 (30 nm) and Ag (12 nm) and optimized growth condition Zn-doped SnO 2 /Ag/Zn-doped SnO 2 multilayer thin films were deposited. The low sheet resistance of 7.2 Ω/□ and high optical transmittance of 85.1% in the 550 nm wavelength region was achieved with 72 nm multilayer film. [ABSTRACT FROM AUTHOR]

Zn-doped hydroxyapatite/polylactic acid (HA/PLA) composite coatings fabricated by spin-coating technique have rarely been studied by other researchers in recent years. In this study, Zn-doped hydroxyapatite (Zn-doped HA) powder were synthesized by chemical precipitation method, and then Zn-doped hydroxyapatite/polylactic acid (Zn-doped HA/PLA) composite coatings were coated on stainless steel substrates using a spin-coating technique for the first time. The effects of heat treatment in air at 600 °C on the composition and morphology of Zn-doped HA/PLA composite coatings with a series of molar ratios of zinc (0 mol%, 5 mol%, 10 mol%, 15 mol% and 20 mol%) were studied. The obtained samples were characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The results showed that Zn 2 + ions had replaced the partial Ca 2 + ions and were doped into hydroxyapatite lattice successfully. The synthetic hydroxyapatite nanoparticles showed rod-like morphology, whereas the substitution of the Zn ions restrained the growth of Zn-doped HA crystal and decreased its size. The surface morphology of Zn-doped HA/PLA composite coatings after sintering at 600 °C for 1 h exhibited a uniform, porous structure with a thickness of 60 μm or so. The introduction of PLA in composite coatings could keep metal substrates from catalyzing the decomposition of HA caused by high temperature heat treatment. [ABSTRACT FROM AUTHOR]

The spinel LiZn x Mn 2− x O 4 ( x ≤0.10) cathode materials have been synthesized by solution combustion method at 600 °C for 3 h. The structure and the morphology of LiZn x Mn 2− x O 4 were characterized by X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM), respectively. All the obtained samples were identified as the spinel structure of LiMn 2 O 4 , the lattice parameters of samples decreased and the particle size increased as the Zn content increased. The effects of Zn-doping on the electrochemical characteristics of LiMn 2 O 4 were investigated by galvanostatic charge–discharge experiments, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Among them, LiZn 0.05 Mn 1.95 O 4 particles presented outstanding cycling stability with a capacity retention of 82.9% at a discharge rate of 1 C (1 C=148 mA h g −1 ) after 500 cycles. Spinel LiZn 0.05 Mn 1.95 O 4 had reversible cycling performance, revealing that doping LiMn 2 O 4 with Zn improves its electrochemical performance. [ABSTRACT FROM AUTHOR]

The XRD patterns show that the peak position of the Zn-doped β-Ga 2 O 3 films shifts to lower angles with the substrate temperature decreasing from 700℃ to room temperature, indicating the incorporation of Zn into Ga 2 O 3 films. Because the ion radius of Ga3+ is 0.61Å and Zn2+ is 0.74Å, the lattice spacing expanses with the increase of Zn concentration and thus the diffraction angle of the characteristic peak becomes smaller. The photoelectric response measurements show that the Zn-doped β-Ga 2 O 3 film based photodetectors manifest much lower dark-current and higher photo-to-dark current ratio. [Display omitted] • P-type Ga 2 O 3 films were obtained by Zn doping using radio frequency magnetron sputtering method. • The doping concentration of Zn has a close relationship with temperature. • Zn-doped β-Ga 2 O 3 based photodetector manifested much lower dark-current and higher photo-to-dark current ratio. Zn-doped Ga 2 O 3 films were prepared using RF magnetron sputtering method at various deposition temperatures. Hall measurement demonstrated the present Zn-doped β-Ga 2 O 3 film was p -type conductivity. The XRD and XRF measurements showed the Zn dopant concentration increased with the decrease of temperature so that the position of the characteristic peak shifted to lower angles. The UV absorption spectra showed that the bandgaps became narrower with the doping concentration of Zn atom increasing. The pure and Zn-doped β-Ga 2 O 3 films were used to fabricate the photodetectors with MSM structure, respectively. The photoelectric response measurements showed that the Zn-doped specimen manifested much lower dark-current and higher photo-to-dark current ratio, but slower photoresponse speed. [ABSTRACT FROM AUTHOR]

Objective(s): This paper describes synthesizing of magnetic nanocomposite with co-precipitation method. Materials and Methods: Magnetic ZnxFe3-xO4 nanoparticles with 0-14% zinc doping (x=0, 0.025, 0.05, 0.075, 0.1 and 0.125) were successfully synthesized by co-precipitation method. The prepared zinc-doped Fe3O4 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM) and UV-Vis spectroscopy. Results: results obtained from X-ray diffraction pattern have revealed the formation of single phase nanoparticles with cubic inverse spinal structures which size varies from 11.13 to 12.81 nm. The prepared nanoparticles have also possessed superparamagnetic properties at room temperature and high level of saturation magnetization with the maximum level of 74.60 emu/g for x=0.075. Ms changing in pure magnetite nanoparticles after impurities addition were explained based on two factors of "particles size" and "exchange interactions". Optical studies results revealed that band gaps in all Zn-doped NPs are higher than pure Fe3O4. As doping percent increases, band gap value decreases from 1.26 eV to 0.43 eV. Conclusion: these magnetic nanocomposite structures since having superparamagnetic property offer a high potential for biosensing and biomedical application. [ABSTRACT FROM AUTHOR]

Abstract: The superconducting properties of Zn-doped Cu0.5Tl0.5Ba2Ca2(Cu3−y Zn y )O10−δ {CuTlZn-1223} (y=0, 0.83, 1.66, 2.5) samples prepared at 820, 830, 850 and 860°C have been compared. The samples were investigated by x-ray diffraction (XRD), dc-resistivity, ac-susceptibility and Fourier Transform Infrared (FTIR) absorption measurements. Almost all the superconducting properties have been increased to their maximum in all CuTlZn-1223 samples synthesized at 860°C, which shows that 860°C is the optimum temperature to achieve CuTlZn-1223 with enhanced superconducting properties. [Copyright &y& Elsevier]

Abstract: This work illustrates the sensing behavior of Zn-doped and undoped In2O3 nanowires toward pollutant gases. An enhanced sensor response to reducing gases (e.g. H2, CO and ethanol) from indium zinc oxide (IZO) nanowires in comparison to In2O3 nanowires is obtained. Zn-doping increases the oxygen vacancies which enhance the oxygen ion adsorption on the nanowire surface. These adsorbed oxygen ions enhance the sensor responses for CO (from 4.5 to 21.5 for 400ppm), H2 (from 4.7 to 32.5 for 4000ppm) and ethanol (from 3.5 to 60 for 100ppm). On the other hand, the sensor response for NO2 reduces (from 17.5 to 6.5 for 1ppm NO2) after Zn-doping. Opposing temperature dependent sensor response from IZO nanowires toward NO2 is observed at higher temperature (above 300°C). This is attributed to the downshift in the Fermi level of IZO due to dissociative NO2 interaction at higher working temperatures which produces oxygen ions that diffuse into the nanowire. [Copyright &y& Elsevier]

Abstract: A series of SmFe1− x Zn x AsO0.8F0.2 samples with x =0, 0.05, 0.1, 0.2 and 0.4 have been successfully synthesized using a solid state method. The lattice parameters are found to increase with increasing Zn doping content. The superconductivity has been definitely suppressed by Zn doping at Fe site with the transition temperature T c being reduced from 52.5K to 23.3K for the sample of x =0.05, and to 18.2K for the sample of x =0.1. For the samples with x >0.1, the superconducting transition vanishes, and, at the meantime, the spin-density-wave anomaly recovers at 140K. The metal to semiconductor transition is also observed in the SmFe1− x Zn x AsO0.8F0.2 system. The behavior of SmFe1− x Zn x AsO0.8F0.2 is very different from that of REFeAsO (RE =rare earth metal), which reveals a very strong electron correlation in SmFe1− x Zn x AsO0.8F0.2. [Copyright &y& Elsevier]

Substituting Zn for Cu is known to rapidly quench superconductivity in the doped perovskites but the mechanism behind it is still not clearly understood. Single phase YBa2(Cu1-xZnx)3O7-δ (x = 0.0 to 0.06) samples were synthesized and characterized using XRD, wet titration, resistivity, and ac susceptibility. Angle-integrated Valence Band Photoemission and Zn K-edge XAFS results clearly show that their oxygen stoichiometry (δ) changes on Zn substitution, thereby adversely affecting the density of free charge carriers and hence the normal state resistivity and the Tc. However, the observed changes in the two happen to be too large to be accounted for solely on the basis of changes in the oxygen stoichiometry δ. We find that the Zn cation acts as a strong "impurity" scattering centre in the YBCO lattice and causes local lattice distortion (LLD). It consequently induces local magnetic moment, seen in our dc susceptibility measurements. It is thus a composite of (Δδ), LLD and possibly also magnetic pair-breaking that is responsible for the rapid quenching of the superconductivity observed with Zn doping in this system. [ABSTRACT FROM AUTHOR]

Abstract: Zn-doped thioindate compounds as ZnInS and ZnIn2S4 have been recently tested as buffer layers for I–III–VI2 solar cells. It has been claimed that such materials are an efficient alternative to the actually used cadmium-based compounds. In this study, Zn-doped layers have been prepared by reactive chemical pulverization in liquid phase. Photothermal measurements have been carried out for several values of x, the precursor solution zinc-to-indium concentration ratio. As the variations of the obtained thermal parameters versus x suggested the existence of an optimal composition, a particular polynomial fitting was applied to the experimental results. This fitting, along with mathematical data processing, led to the optimal value x =0.33. [Copyright &y& Elsevier]

Abstract: This study presents the synthesis and activity of ZnSO4–TiO2 coated Raschig rings (RR). The activity of the Zn-doped catalyst (from now on Zn–TiO2/RR) was found to be higher than of the pure Degussa P25 TiO2 during the photodegradation of organic compounds. The most suitable doping level of TiO2 for Zn was 4mol% noted as Zn (4% mol)–TiO2/RR during the degradation of azo-dye Orange II and of the transparent 2-propanol solutions. The degradation kinetics of the probe molecules was systematically investigated as a function of the catalyst make-up and some of the solution parameters. XPS measurements show Zn 2p3/2 peak positions for Zn–TiO2 sample in the range 1021.58–1022.00eV. This energy range was observed to be lower than 1022.54eV recorded for the reference ZnSO4 sample. This shift indicates that the Zn-atoms act as electron acceptors in the Zn-doped TiO2 and may be responsible for the higher catalytic activity observed for the Zn (4% mol)–TiO2/RR compared to the TiO2/RR photocatalyst during Orange II degradation. Insight is given onto the complex oxidation/reduction processes takes place at the interface of Zn–TiO2. The changes occurring in the Zn, TiO2 and S catalyst components are discussed as a function of the time of reaction. The Zn–TiO2 catalyst was characterized by elemental analysis (EA), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), confocal microscopy, X-ray photoelectron microscopy (XPS) and X-ray diffraction (XRD). [Copyright &y& Elsevier]

Abstract: The influence of Zn-doping on the crystal structure and magnetic properties of the spin ladder compounds La2Cu2O5 (4-leg) and La8Cu7O19 (5-leg) have been investigated. The La2(Cu1− x Zn x )2O5 and La8(Cu1− x Zn x )7O19 solid solutions were obtained as single phases with via the solid-state reaction method in the temperature range between 1005–1010°C and 1015–1030°C in oxygen and air atmospheres, respectively. The lattice parameters a and c of the monoclinic crystal structures as well as the unit cell volume V increase with increasing x, while b and β decrease for both series. The magnetic susceptibilities χ of both series show a very similar behavior on temperature as well as on Zn-doping, which is supposed to be due to the similar Cu–O coordination in both La2Cu2O5 and La8Cu7O19. For low Zn-doping (), a spin-chain like behavior is found. This quasi-one-dimensional behavior is strongly suppressed in both series for . Here, the maximum (characteristic for spin chains) in χ(T) disappears and χ(T) decreases monotonically with increasing temperature. [Copyright &y& Elsevier]

The electrical resistivity of La2Ni1−xZnxO4+δ polycrystalline samples with x varying from 0.1 to 0.5% atom are investigated in relation with the formation and the correlation lengths of charge and spin ordered stripes. It appears almost impossible to explain the activated transport properties by conventional semi-conductor models where the holes are homogeneously distributed in the lattice. Present results rather suggest that the Zn-doping plays an important role on the charge transport and modifies the manner that the holes and spins are arranged in the system. [Copyright &y& Elsevier]

The influence of Zn doping on the physical and electrical properties of the Tl-1223 phase has been investigated for samples with the composition (Tl0.5Pb0.5)(Sr0.9Ba0.1)2Ca2(Cu1−xZnx)3O8+δ (x=0, 0.01, 0.05 and 0.1). Sr–Ba–Ca–Cu–Zn containing precursor materials were prepared via malic acid gels followed by a calcination step at 900 °C. Tl2O3 and PbO were added by co-milling. Sintering in oxygen atmosphere yielded high-quality superconducting material. Oxygen annealing, re-grinding and re-sintering improved the electrical properties, leading to critical temperatures (Tc(0)) of 117 K and critical current densities up to 3800 A cm−2 at 77 K for bulk phase material. The addition of Zn increased the content of the Tl-1212 phase, changed the microstructure, decreased the transition temperature slightly and reduced the critical current density at 77 K. [Copyright &y& Elsevier]

We propose the inclusion of a novel In(OH)3:Zn2+ buffer layer for fabricating high-efficiency CIGS solar cells. This buffer layer was deposited using a solution consisting of ZnCl2, InCl3·4H2O, and thiourea. The In(OH)3:Zn2+ films showed high resistivities of 2.1×108 Ω cm and transmittance of above 95% in the visible range. We expected two effects due to this new buffer layer: first is the formation of a passivation layer on the CIGS surface and the second is Zn-doping into CIGS layer, resulting in the formation of a buried junction. A cell efficiency of 14.0% (Voc: 0.575 V, Jsc: 32.1 mA/cm2, FF: 0.758) was achieved by using an In(OH)3:Zn2+ buffer layer, without the light soaking effect. [Copyright &y& Elsevier]