Impact Of Doping Research Articles

Impact of dopants on electrical conductivity of proton-conducting SrHfO3 perovskite

For reliable long-term operation of solid oxide electrochemical devices for the hydrogen energy system, an electrolyte with high ionic conductivity and excellent chemical stability is required. SrHfO3-based perovskites are known for their high chemical resistance; however, their ionic conductivity must be increased. In the present research, the effect of doping with yttrium and ytterbium on the electrical properties of strontium hafnate was studied for the first time. The crystal structure, solubility limit of the dopants, morphology and electrical properties of SrHf1-xMxO3-δ (M = Y, Yb) materials were investigated by the X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, direct current four-probe technique, and impedance spectroscopy. The solubility limits of Y and Yb in SrHfO3 were found to lie slightly below x = 0.10. It was revealed that yttrium doping is more favorable for the grain growth and densification of ceramics. A comparative analysis of the influence of dopant type (Y, Yb and Sc) and concentration on the electrical properties of SrHfO3 is provided.

Zn2+ ion doping's impact on the vibration spectroscopic properties of higher absorption ions: application to the determination of optical constant properties: advancements in nanotechnology applications

Zn2+ ion doping's impact on the vibration spectroscopic properties of higher absorption ions: application to the determination of optical constant properties: advancements in nanotechnology applications

Effect of Co Doping on the Physical Properties and Organic Pollutant Photodegradation Efficiency of ZnO Nanoparticles for Environmental Applications.

This paper presents a comprehensive investigation of the synthesis and characterization of Zn1-xCoxO (0 ≤ x ≤ 0.05) nanopowders using a chemical co-precipitation approach. The structural, morphological, and vibrational properties of the resulting ZnO nanostructures were assessed through X-ray diffraction, scanning electronic microscopy, and Raman spectroscopy to examine the influence of cobalt doping. Remarkably, a notable congruence between the experimental results and the density functional theory (DFT) calculations for the Co-doped ZnO system was achieved. Structural analysis revealed well-crystallized hexagonal wurtzite structures across all samples. The SEM images demonstrated the formation of spherical nanoparticles in all the samples. The vibrational properties confirmed the formation of a hexagonal wurtzite structure, with an additional Raman peak corresponding to the F2g vibrational mode characteristic of the secondary phase of ZnCo2O4 observed at a 5% cobalt doping concentration. Furthermore, a theoretical examination of cobalt doping's impact on the elastic properties of ZnO demonstrated enhanced mechanical behavior, which improves stability, recyclability, and photocatalytic activity. The photocatalytic study of the synthesized compositions for methylene blue (MB) dye degradation over 100 min of UV light irradiation demonstrated that Co doping significantly improves photocatalytic degradation. The material's prolonged lifetime, reduced rate of photogenerated charge carrier recombination, and increased surface area were identified as pivotal factors accelerating the degradation process. Notably, the photocatalyst with a Zn0.99Co0.01O composition exhibited exceptional efficiency compared to that reported in the literature. It demonstrated high removal activity, achieving an efficiency of about 97% in a shorter degradation time. This study underscores the structural and photocatalytic advancements in the ZnO system, particularly at lower cobalt doping concentrations (1%). The developed photocatalyst exhibits promise for environmental applications owing to its superior photocatalytic performance.

Impact of dopant (Mg, Be) elements on structural and optoelectronic properties of RbCaF3: GGA-PBE based computational estimation

Impact of dopant (Mg, Be) elements on structural and optoelectronic properties of RbCaF3: GGA-PBE based computational estimation

Impact of Dopants on Suppressing Gas Evolution from High-Nickel Layered Oxide Cathodes

Impact of Dopants on Suppressing Gas Evolution from High-Nickel Layered Oxide Cathodes

Impact of dopant X in zirconia on carbon deposition at the Nickel/X-stabilized zirconia(XSZ) surface in dry CH4 and CH4/H2O environments: First-principles density functional theory calculation and experimental study

The impact of a dopant (X; X = Y or Sc) in zirconia on carbon deposition in CH4 and CH4/H2O environments was studied experimentally and via first-principles calculations. In the CH4 environment, the apparent activation energy for the carbon deposition of Ni/ScSZ was lower than that of Ni/YSZ. SEM/EDS observation indicated the Ni/XSZ interface was key to elucidating the dopant-induced difference. To clarify the difference, the calculation presented two mechanisms: first, the vacancy in ScSZ rather than that in YSZ was readily moved to a neighboring site, thereby stabilizing the vacancy configuration after CH–CH bonding. Second, Ni was readily distorted in Ni/ScSZ at the specific vacancy configuration, thereby decreasing the forward activation energy. In CH4/H2O environment, the calculation showed larger dopant Y caused steric hindrance to prevent CH + O→CHO which was the sensitive reaction in the steam reforming. This explained lower reforming rate in Ni/YSZ than in Ni/ScSZ.

Doping-induced bandgap tuning in armchair graphene nanoribbons and its impact on electron transport properties on ZAPn – A DFT study

Graphene, sp2 hybridised-2D material has been widely reviewed for its fabulous structural, electronic, magnetic and optical properties. However, its employment in energy-related devices are controlled due to its semi-metallic nature. A quasi one-dimensional structure of graphene is called as graphene nanoribbon (GNR). Tuning the band gap of GNR based on its width can be achieved via doping. The present work envisages, the doping performance on the electronic properties of armchair graphene nanoribbon AGNR (N9) doped with Boron (B), Nitrogen (N) and Phosphorus (P) in a Z-shape. The effect of B, N, and P dopants in AGNR(N9) systems were analysed by varying the concentration from 0.75 % to 3.03 %. Our results predicts that the band gap has been reduced by the impact of dopants, and also ZAPn systems shows better results in lower concentration of dopants than ZABn and ZANn systems. Further, it is observed that, with the increase in the concentration of P dopants, their electronic structure is transformed from n-type to p-type. Transport calculations were performed for ZAPn systems, and their properties were analyzed with the help of transmission spectrum, device density of states (DDOS), and I-V characteristics. All the doped as well as the pristine two-probe device structures established non-linear current vs. voltage characteristics. The ZAP3 doped system achieved a maximum current of 60 µA. The present study will be established to construct AGNR(N9) based nano-electronic devices.

Cubic to pseudo-cubic tetragonal phase transformation with Mg, Ca, and Be doping and its impact on optoelectronic, elastic and mechanical properties of SrHfO3

The structural, optoelectronic, elastic and mechanical properties of pure, Ca-, Mg-, and Be-doped SrHfO3 have been computed with CASTEP code based on density functional theory. The structure of SrHfO3 remains cubic with 1.40% doping concentration of Ca, Mg and Be whereas it is altered in pseudo-cubic tetragonal at the doping concentration of 4.22% and 7.04%. Reduction in the electronic band gap is observed in all the doping concentrations. For detailed explanation of electronic band gap reduction density of states (DOS), partial DOS and elemental partial DOS have also been computed. DOS plays a very meaningful role in understanding the behavior of band gap at different doping. The impact of dopants on the optical properties of pure SrHfO3 indicates the increment in refractive index (n), absorption (I), Loss function (L) and extinction coefficient (k) as well. For both cubic and tetragonal structures our compound shows mechanical stability in all doping percentages of Ca, Mg and Be other than the 1.40% of Mg and Be for cubic geometry. Over and above that to examine the mechanical properties of material like ductility and brittleness we have also computed the different characteristics such as Bulk modulus (B), Shear modulus (G), G/B ratio, Cauchy Pressure (CP) and Anisotropic factor (A). Interestingly, the material is purely ductile on all concentrations of Ca, Mg, and Be and shows brittleness only at the doping concentration of 1.40% of Ca.

Grain growth and segregation in Fe-doped SrTiO3: Experimental evidence for solute drag

In functional ceramics, the impact of dopants on bulk crystals is generally well understood. Their impact on grain boundaries is less well known. The present study investigates the impact of acceptor dopants on grain growth in strontium titanate. Scanning electron microscopy and analytical (scanning) transmission electron microscopy have been used to gain knowledge on Fe segregation behavior, grain sizes, and grain size distributions of SrTiO3. While undoped microstructures show normal grain growth at low temperatures (<1350 °C), doped microstructures evolve bimodally. With increasing acceptor dopant concentration, an increasing population of small grains develops. It is shown that Fe segregates to the grain boundaries due to its negative charge and a positive boundary potential. Thus, the experimental findings seem to be well explained by the theory of solute drag: The diffusion of segregated defects (‘solutes’) at grain boundaries can retard grain boundary migration.

Yttrium and cobalt doped LaNiO3 nanoparticles synthesis and solar light driven photocatalytic removal of Rhodamine B

La1-xYxNi1−yCoyO3 nanoparticles were fabricated via facile microemulsion route and impact of dopants was evaluated based on various structural, electrical and optical properties. The X-ray diffraction pattern confirmed the distorted rhombohedral symmetry with space group R3c¯ of La1-xYxNi1−yCoyO3 with particle size in 76–92 nm range. Dielectric parameters showed high dispersion at low frequency, while remained constant at low values. The AC conductivity showed increasing trend with doping in association with enhanced polarization. Band gap was tuned from 2.75 eV for pure LaNiO3 (LNO) to 2.60 eV for doped LNYC3 material in agreement with decline in PL intensity for improved catalytic response. The LNYC3 showed superior RhB degradation efficacy of 91% versus pure LNO (63%) in 210 min under visible illumination with rate constant of 0.0513 and 0.0029 min−1, respectively. In view of its promising catalytic activity, LNYC3 has potential application for the removal of dyes from effluents under solar light irradiation.

Synthesis of Ni doped barium hexaferrite by microemulsion route to enhance the visible light-driven photocatalytic degradation of crystal violet dye

The pristine and Ni doped BaNixFe12-xO19 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) NPs have been fabricated via facile microemulsion approach and the impact of dopants was explored based dielectric, optical, structural and the photocatalytic properties of BaNixFe12-xO19 nanoparticles. X-ray diffraction and Raman study confirmed the formation of regular hexagonal geometry with space group P63/mmc with crystallite size in 32–50 nm range. Functional groups were identified using FTIR analysis. The remanence (Pr), saturation polarization (Ps) and coercivity (Hc) was explored by P-E loop analysis and the value of Pr and Ps was enhanced with the concentration of dopant. According to PL spectra, highly doped materials had a higher charge separation (e−- h+) and low recombination rate, which resulted in higher photocatalytic degradation activity of fabricated nanomaterials. The optical band gap was found to be 1.78 eV versus undoped (2.60 eV for pristine BaFe12O19). Due to polarizations, the dielectric loss, dielectric constant and tangent loss values were declined, while AC conductivity was enhanced. Photocatalytic performance of doped and undoped samples under visible right irradiation was studied for crystal violet dye. For 100 min exposure to visible light, the highly doped catalyst exhibits 97% degradation versus 60% in case of pristine this is attributed to efficient electron-hole pair separation. Furthermore, quenching effect of different scavengers indicated that hydroxyl radical had a main role, and e− or h+ played a minimal role in CV dye degradation. The enhanced properties due to doping make BaNixFe12-xO19 a potential candidate for photocatalytic applications under visible light irradiation.

The impact of dopants (B, H) on the mechanical behavior and tribological performance of DLC film under water lubrication

The tribological behaviors of diamond like carbon films are affected by the surrounding environment. To improve the properties of DLC films, element doping or structural design were carried out. In this work, the B&H co-doped DLC films were successfully deposited on 316 L substrate and Si wafer by closed filed unbalanced magnetron sputtering equipment and studied the effect of H content on the mechanical and tribological properties of the B&H co-doped DLC films. The results indicate that B&H-DLC-2sccm film has the best mechanical performance and adhesive force. Besides, for the friction properties, B&H-DLC-2sccm film has the lowest friction coefficient and wear rate after sliding against Si3N4 ball. This study provides another solution to improve the water lubrication effect of mechanical parts.

Enhanced in vitro antibacterial activity of ZnO and Mn–Mg co-doped ZnO nanoparticles: investigation of synthesis, characterization, and impact of dopant

Enhanced in vitro antibacterial activity of ZnO and Mn–Mg co-doped ZnO nanoparticles: investigation of synthesis, characterization, and impact of dopant

Nvestigation of Uv-Vis Characteristics of Pure/Doped Polystyrene Thin Films Prepared by Solution Casting Method

Minimizing the size of electronics to achieve thinner and lighter devices makes the shrinking of the components inevitable. The focus of this research is to incorporate dopants into the Polystyrene (PS) matrix to fabricate thin films with high efficiency and flexibility. Presented is a very simple approach of doping PS thin films with various dopants. The absorption spectra of the films were studied at the wavenumber range (300-700 nm). Effects of doping on optical properties such as, absorbance, transmittance, energy, absorption coefficient, extinction coefficient, and dielectric constant were derived. This study reveals that all these parameters have impact of dopants on PS.

Synthesis and Zn Doping's Impact on CeO2 Nanoparticles for Improved Photocatalytic Evaluation, Antibacterial and Anticancer Analyses

This work uses Psidium guajava leaf extracts to easily and quickly synthesise Cerium nanoparticles (Ce NPs) and Zn: CeO2 NPs (Zn-Ce NPs) (PGE). The generated G - CeO2 and Zn: CeO2 NPs were examined using X-ray diffraction (XRD), Energy Dispersive Analysis of X-Ray (EDAX), Fourier transformed infrared spectroscopy (FT-IR), UV-Visible spectroscopy (UV-Vis), and Scanning Electron Microscopy (SEM) techniques. The presence of OH, -NH2, and C=O groups, which were essential for the synthesis of G-CeO2 and Zn: CeO2 NPs, was detected by FT-IR spectroscopy. The XRD analysis supports the fluorite cubic structure of the resulting particles for G-CeO2 and Zn: CeO2 NPs. The findings of the elemental analysis by EDX demonstrated that the doping effects of Zn2+ in G-CeO2 NPs effectively enhanced the percentages of cerium and oxygen. G-CeO2 and Zn: CeO2 nanoparticles were evenly dispersed, and a SEM microscopic investigation also revealed that the produced nanoparticles were spherical in shape. Both the G-CeO2 and Zn: CeO2 nanoparticles demonstrated effective antibacterial and antifungal properties. To measure photocatalytic activity, the degradation of methylene blue (MB) in aqueous solution under visible light irradiation was utilised. The findings demonstrated that Zn doping considerably increased Ce NPs' photocatalytic activity. Using Zn dopant, it has been discovered that the optical band gap of Ce NPs has decreased from 3.69 eV to 3.55 eV. Both the G-CeO2 and Zn: CeO2 nanoparticles demonstrated effective antibacterial and antifungal properties. By increasing the concentration of both G-CeO2 and Zn: CeO2 NPs, the viability of the cancer cells L929 and HCT 116 was partly reduced.

A comparative study of different rare-earth (Gd, Nd, and Sm) metals doped ZnO thin films and its room temperature ammonia gas sensor activity: Synthesis, characterization, and investigation on the impact of dopant

Zinc oxide and rare earth (Gd, Nd, and Sm) doped zinc oxide thin film has been synthesized chemically by facile and cost-effective SILAR method. The impact of rare-earth doping on structural, morphological, and optical properties of ZnO films has been investigated using various characterization techniques. The stylus profiler method is employed to find the thickness of the films. The doping of rare earth elements reduces the thickness of the films. The XRD and SEM results suggest that the rare-earth metal is successfully incorporated into the ZnO lattice. The elemental mapping and EDS results show that homogeneous scatter of zinc (Zn), oxygen (O), gadolinium (Gd), neodymium (Nd), and samarium (Sm) compounds are found in the doped films. The transmission and bandgap of the films are enhanced due to doping. The doped ZnO films have exhibited significant enhancement in ammonia gas sensors at room temperature. Nd doping is effective than the Sm doped ZnO and Gd doped ZnO to sense the ammonia in terms of recovery time, response time, and sensitivity.

Impact of Dopants on Charge Transport across Organic–Organic Semiconductor Junctions

Impact of Dopants on Charge Transport across Organic–Organic Semiconductor Junctions

First-Principles Calculation and Multi-Scale Observation for a Carbon Deposition on a SOFC Anode Near the Interface

The nickel/yttria-stabilized zirconia (Ni/YSZ) and nickel/scandia-stabilized zirconia (Ni/ScSZ) have widely used as an anode for solid oxide fuel cells (SOFCs). The high operation temperature allows an SOFC to operate on a wide range of fuels, including hydrocarbons and coal syngas. Ni is also a catalyst for carbon deposition reactions which destroy the anode microstructure. Meanwhile, the carbon deposited on the electrode can be used for different ways. It is important to control the carbon deposition on the electrode; therefore, the carbon deposition model needs to be developed.In this study, carbon deposition site in the Ni/YSZ and Ni/ScSZ was studied through first-principles calculation and multi-scale observation using SEM and TEM. Observation showed that the carbon deposition was progressed not in the overall Ni surface but in the specific sites such as the interfaces and Ni(211) facet at low temperature. The carbon deposition rate strongly depended on the electrode structure at microscales. All calculations here are performed employing the periodic density functional theory (DFT) method implemented in the Vienna Ab-Initio Simulation Package (VASP). The Ni/YSZ and Ni/ScSZ atomic models are developed to discuss the CH adsorption which is the initial step of the carbon deposition. The CH adsorption energy in the concentrated vacancies at the Ni/YSZ interface was much lower than that in the Ni(111) facet, indicating that concentrated vacancies become the active site of the carbon deposition. However, the CH adsorption energy in the dispersed vacancies are almost the same as that in the Ni(111) facet. It is shown that vacancy patterns play an important role in the carbon deposition rate. The impact of dopant in the anode on the carbon deposition is also studied. DFT calculation gives an useful hint to develop the carbon deposition model with considering the electrode structure.

Structure and properties of amorphous uranium dioxide

Amorphous uranium dioxide (UO2) has been modelled on the atomic scale using a combination of quantum mechanical (density functional theory) and classical forcefield methods (molecular dynamics and reverse Monte-Carlo). The atomic scale structure of the amorphous state has been predicted and is presented in the form of simulated X-ray diffraction patterns, pair correlation functions and bond angle distributions. These are shown to be consistent with the experimental patterns previously reported. To enable accurate calculation of the energies and magnetic properties, using quantum mechanics, reverse Monte-Carlo was used to generate reduced cells from larger molecular dynamic melt-quenches. This allowed density functional theory energy minimisation for structures consistent with the amorphous state. Building on this, the material's propensity to deviate from stoichiometry, the magnetic structure and amorphous UO2 surface energy were computed. Non-stoichiometry is accommodated more readily in the amorphous system than in crystalline UO2. This indicates that deviations from stoichiometry in fuel (for example as a result of operation) will be accommodated at amorphous phases, if present, leaving a more stoichiometric crystalline phase – impacting processes including fission gas mobility, melting points and a number of other safety relevant properties. The magnetic structure of bulk amorphous UO2 is predicted to be a spin-glass, unlike crystalline UO2 which has anti-ferromagnetic ordering at 0 K. The surface energy of amorphous UO2 is computed to be 0.79 Jm−2, which is similar to the experimentally observed surface energy of grain boundary bubbles in UO2 and comparable to the surface energies reported for crystalline UO2. Results are pertinent to ongoing efforts to understand the nature of grain boundaries in nuclear fuels, to model fission gas release from them, radiation induced amorphization and the impact of dopants and impurities on nuclear fuel's manufacture and in-reactor behaviour.

Review Article: Atomic layer deposition of doped ZnO films

This article reviews the process-structure-property relationship in doped ZnO thin films via atomic layer deposition (ALD). ALD is an important manufacturing-scalable, layer-by-layer, thin film deposition process that precisely controls dopant type and concentration at the nanoscale. ZnO is an important technological material, which can be doped to modulate structure and composition to tailor a wide variety of optical and electronic properties. ALD doped ZnO is viewed as a transparent conducting oxide for application in solar cells, flexible transparent electronics, and light-emitting diodes. To date, there are 22 elements that have been reported as dopants in ZnO via ALD. This article studies the underlying trends across dopants and establishes generalized relationships for (1) the role of ALD process parameters, (2) the impact of these parameters on the structure of the ZnO matrix, and (3) the impact of dopants on the optical and electrical properties. The article ends with a brief discussion on the limitations of the ALD-based doping scheme, knowledge gaps in the compositional maps, and a perspective on the future of ALD doped ZnO films.