Enhancement Of Current Density Research Articles

Enhancing Carrier Mobility in Monolayer MoS2 Transistors with Process-Induced Strain.

Two-dimensional electronic materials are a promising candidate for beyond-silicon electronics due to their favorable size scaling of electronic performance. However, a major challenge is the heterogeneous integration of 2D materials with CMOS processes while maintaining their excellent properties. In particular, there is a knowledge gap in how thin film deposition and processes interact with 2D materials to alter their strain and doping, both of which have a drastic impact on device properties. In this study, we demonstrate how to utilize process-induced strain, a common technique extensively applied in the semiconductor industry, to enhance the carrier mobility in 2D material transistors. We systematically varied the tensile strain in monolayer MoS2 transistors by iteratively depositing thin layers of high-stress MgOx stressor. At each thickness, we combined Raman spectroscopy and transport measurements to unravel and correlate the changes in strain and doping within each transistor with their performance. The transistors displayed uniform strain distributions across their channels for tensile strains of up to 0.48 ± 0.05%, at 150 nm of stressor thickness. At higher thicknesses, mechanical instability occurred, leading to nonuniform strains. The transport characteristics systematically varied with strain, with enhancement in electron mobility at a rate of 130 ± 40% per % strain and enhancement of the channel saturation current density of 52 ± 20%. This work showcases how established CMOS technologies can be leveraged to tailor the transport in 2D transistors, accelerating the integration of 2D electronics into a future computing infrastructure.

Dimerized Nonfused Electron Acceptor Based on a Thieno[3,4-c]pyrrole-4,6-dione Core for Organic Solar Cells.

In this work, the first dimerized nonfused electron acceptor (NFEA), based on thieno[3,4-c]pyrrole-4,6-dione as the core, has been designed and synthesized. The dimerized acceptor and its single counterpart exhibit similar energy levels but different absorption spectra due to their distinct aggregation behavior. The dimerized acceptor-based organic solar cells (OSCs) demonstrate a higher power conversion efficiency of 11.05%, accompanied by enhanced thermal stability. This improvement is attributed to the enhancement of the short-circuit current density and fill factor, along with an increase in the glass transition temperature. Characterizations of exciton dynamics and film morphology reveal that a dimerized acceptor-based device possesses an enhanced exciton dissociation efficiency and a well-established charge transport pathway, explaining its improved photovoltaic performance. All these results indicate that the dimerized NFEA as a promising candidate can achieve efficiency-stability-cost balance in OSCs.

Operando Studies for CO2/CO Reduction in Flow‐Based Devices

AbstractElectrocatalytic CO2 reduction reaction (CO2RR) conducted in a flow‐based device exhibits a substantial enhancement in Faradaic efficiency and catalytic current density compared to a conventional H‐type configuration. This highlights the distinct catalytic environment and behavior inherent in flow cells as opposed to H cells. To investigate the authentic properties of a catalyst within a flow‐based device, customized flow cells have been specifically devised for operando techniques during CO2RR and CORR, rather than resorting to an in‐situ three‐electrode H‐type configuration with its disparate catalytic environment and performance. This approach ensures a catalytic environment identical to that employed in electrochemical measurements. This review delineates the disparities between H‐type and flow‐based cells as well as the operando techniques tailored for flow‐based devices, including X‐ray absorption spectroscopy and Raman spectroscopy, preserving a consistent catalytic environment. It also compiles recent findings on copper‐based systems using operando flow‐based devices. The operando insights reveal a significant augmentation in catalytic current density, impacting both chemical properties and crystal structures. Furthermore, the observation of various catalytic intermediates enriches our comprehension. In essence, the application of operando techniques to flow‐based devices furnishes a comprehensive understanding of the catalytic behavior exhibited by diverse systems, propelling progress toward achieving Net Zero emissions.

Effect of nano-Ag addition on the superconducting properties of MWCNT doped magnesium diboride superconductor

Bulk MgB2 superconductor added with nano silver (Ag), multiwalled carbon nanotube (MWCNT) and both the added (i.e., nano-Ag and MWCNT) samples were synthesized. The influence of nano-Ag and MWCNT addition on the structural and superconducting properties were studied. The XRD analysis confirms the formation of hexagonal MgB2 superconductor. Microstructural studies of all the synthesized samples are carried out by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). The superconducting properties such as critical temperature (Tc), magnetic critical current density (Jc), irreversibility field (Birr) and flux pinning properties of all the synthesized samples were investigated at 10 K and field up to 7 T. Nano Ag added MWCNT doped MgB2 shows maximum enhancement in the critical current density i.e., 5.83 × 104 A/cm2 at 5 T and 10 K.

Self-Assembled Molecules with Asymmetric Backbone for Highly Stable Binary Organic Solar Cells with 19.7 % Efficiency.

The hole-transporting material (HTM), poly (3,4-ethylene dioxythiophene) poly(styrene sulfonate) (PEDOT : PSS), is the most widely used material in the realization of high-efficiency organic solar cells (OSCs). However, the stability of PEDOT : PSS-based OSCs is quite poor, arising from its strong acidity and hygroscopicity. In addition, PEDOT : PSS has an absorption in the infrared region and high highest occupied molecular orbital (HOMO) energy level, thus limiting the enhancement of short-circuit current density (Jsc) and open-circuit voltage (Voc), respectively. Herein, two asymmetric self-assembled molecules (SAMs), namely BrCz and BrBACz, were designed and synthesized as HTM in binary OSCs based on the well-known system of PM6 : Y6, PM6 : eC9, PM6 : L8-BO, and D18 : eC9. Compared with BrCz, BrBACz shows larger dipole moment, deeper work function and lower surface energy. Moreover, BrBACz not only enhances photon harvesting in the active layer, but also minimizes voltage losses as well as improves interface charge extraction/ transport. Consequently, the PM6 : eC9-based binary OSC using BrBACz as HTM exhibits a champion efficiency of 19.70 % with a remarkable Jsc of 29.20 mA cm-2 and a Voc of 0.856 V, which is a record efficiency for binary OSCs so far. In addition, the unencapsulated device maintains 95.0 % of its original efficiency after 1,000 hours of storage at air ambient, indicating excellent long-term stability.

Enhanced trapped magnetic field in bulk (Gd, Y, Er) Ba2Cu3O7-y via varied liquid sources in top-seeded infiltration growth process

The practical applications of the bulk superconductors are determined by the trapped field (TF) and its overall performance. This study aims to demonstrate the effect of various compositions of liquid sources on the trapped field performance of bulk superconductors fabricated using the Top-Seeded Infiltration Growth process (TSIG) in air. We utilized a combination of different liquid sources, Ba3Cu5O8, Yb2O3: BaCuO2: CuO (1:10:6) and ErBa2Cu3Oy + Ba3Cu5O8 (1:1) to fabricate the ternary bulk (Gd, Y, Er) Ba2Cu3O7-y (Gd, Y, Er)-123. The use of these liquid sources demonstrated a pivotal role in fabricating single-domain bulks, showcasing significant variation in the trapped field performance. Specifically, the bulk fabricated using ErBa2Cu3Oy + Ba3Cu5O8 (1:1) as a liquid source exhibited the best-trapped field performance, showcasing an improvement of 42.92 % compared to the bulk obtained using conventional Ba3Cu5O8 as the liquid source. An enhancement in the critical current density below 77 K was observed in the bulk material produced utilizing Ba3Cu5O8 as the liquid source, with a Jc (3T, 50 K) value reaching 244 kA/cm2. The flux pinning force density (Fp) was analyzed for all samples to understand the pinning mechanisms in ternary (Gd, Y, Er)-123 bulk materials. Furthermore, the maximum trapped field for a 30 mm bulk sample fabricated using a mixture of ErBa2Cu3Oy + Ba3Cu5O8 (1:1) was measured at 0.336T. These results emphasize the potential for enhancing or controlling the trapped field performance of the TSIG-processed RE-123 bulks by optimizing the liquid source according to the intended applications of the bulk.

Light emitting diode and laser diode system behaviour description and their performance signature measurements

Abstract This paper has clarified the light emitting diode and laser diode system behaviour description and their external quantum efficiency measurements. Light output of LED spontaneous emission and laser diode stimulated emission are clarified. Stimulated and amplified spontaneous emission of laser diode and LED system configuration are demonstrated. The management of hybrid light sources spectrum illumination interaction for efficient solar cells light intensity and short circuit current density enhancement. The laser diode has presented better performance in the light output power especially under the same temperature effects. It is ensured that the dramatic effects of the temperature on both laser diode performance efficiency.

Molecular Design of Fully Nonfused Acceptors for Efficient Organic Photovoltaic Cells.

The nonfused thiophene-benzene-thiophene (TBT) unit offers advantages in obtaining low-cost organic photovoltaic (OPV) materials due to its simple structure. However, OPV cells, including TBT-based acceptors, exhibit significantly lower energy conversion efficiencies. Here, we introduce a novel approach involving the design and synthesis of three TBT-based acceptors by substituting different position-branched side chains on the TBT unit. In comparison to TBT-10 and TBT-11, TBT-13, which exclusively incorporates α-position branched side chains with a large steric hindrance, demonstrates a more planar and stable conformation. When blended with the donor PBQx-TF, TBT-13-based blend film achieves favorable π-π stacking and aggregation characteristics, resulting in excellent charge transfer performance in the corresponding device. Due to the simultaneous enhancements in short-circuit current density and fill factor, the TBT-13-based OPV cell obtains an outstanding efficiency of 16.1%, marking the highest value for the cells based on fully nonfused acceptors. Our work provides a practical molecular design strategy for high-performance and low-cost OPV materials.

The effect of intrinsic magnetic order on electrochemical water splitting

To reach a long term viable green hydrogen economy, rational design of active oxygen evolution reaction (OER) catalysts is critical. An important hurdle in this reaction originates from the fact that the reactants are singlet molecules, whereas the oxygen molecule has a triplet ground state with parallel spin alignment, implying that magnetic order in the catalyst is essential. Accordingly, multiple experimentalists reported a positive effect of external magnetic fields on OER activity of ferromagnetic catalysts. However, it remains a challenge to investigate the influence of the intrinsic magnetic order on catalytic activity. Here, we tuned the intrinsic magnetic order of epitaxial La0.67Sr0.33MnO3 thin film model catalysts from ferro- to paramagnetic by changing the temperature in situ during water electrolysis. Using this strategy, we show that ferromagnetic ordering below the Curie temperature enhances OER activity. Moreover, we show a slight current density enhancement upon application of an external magnetic field and find that the dependence of magnetic field direction correlates with the magnetic anisotropy in the catalyst film. Our work, thus, suggests that both the intrinsic magnetic order in La0.67Sr0.33MnO3 films and magnetic domain alignment increase their catalytic activity. We observe no long-range magnetic order at the catalytic surface, implying that the OER enhancement is connected to the magnetic order of the bulk catalyst. Combining the effects found with existing literature, we propose a unifying picture for the spin-polarized enhancement in magnetic oxide catalysts.

Evaluation of temperature dependent vortex pinning properties in strongly pinned YBa2Cu3O7-δ thin films with Y2BaCuO5 nanoinclusions

The pinning of quantized magnetic vortices in superconducting YBa2Cu3O7- δ(YBCO or Y123) thin films with Y2BaCuO5 (Y211) nanoinclusions have been investigated over wide temperature range (4.2–77 K). The concentration of Y211 nanoinclusions has been systematically varied inside YBCO thin films prepared by laser ablation technique using surface modified target approach. Large pinning force density values (Fp ∼ 0.5 TNm−3 at 4.2 K, 9 T) have been observed for the YBCO film with moderate concentration of Y211 nanoinclusions (3.6 area % on ablation target). In addition, uniform enhancement in critical current density (Jc) was observed in the angular dependent Jc measurement of YBCO+Y211 nanocomposite films. Y211 nanoinclusions have been found to be very efficient in pinning the quantized vortices thereby enhancing the in-field Jc values over a wide range of temperature. Increasing the concentration of Y211 secondary phase into Y123 film matrix results into agglomeration of Y211 phase and observed as increased Y211 nanoparticle size. These larger secondary phase nanoparticles are not as efficient pinning centers at lower temperatures as they are at higher temperatures due to substantial reduction of the coherence length at lower temperatures. Investigation of the temperature dependence of Jc for YBCO+Y211 nanocomposite films has been conducted and possible vortex pinning mechanism in these nanocomposite films has been discussed.

Decoration of Ag nanoparticles on CoMoO4 rods for efficient electrochemical reduction of CO2.

Hydrothermal and photoreduction/deposition methods were used to fabricate Ag nanoparticles (NPs) decorated CoMoO4 rods. Improvement of charge transfer and transportation of ions by making heterostructure was proved by cyclic voltammetry and electrochemical impedance spectroscopy measurements. Linear sweep voltammetry results revealed a fivefold enhancement of current density by fabricating heterostructure. The lowest Tafel slope (112mV/dec) for heterostructure compared with CoMoO4 (273mV/dec) suggested the improvement of electrocatalytic performance. The electrochemical CO2 reduction reaction was performed on an H-type cell. The CoMoO4 electrocatalyst possessed the Faraday efficiencies (FEs) of CO and CH4 up to 56.80% and 19.80%, respectively at - 1.3V versus RHE. In addition, Ag NPs decorated CoMoO4 electrocatalyst showed FEs for CO, CH4, and C2H6 were 35.30%, 11.40%, and 44.20%, respectively, at the same potential. It is found that CO2 reduction products shifted from CO/CH4 to C2H6 when the Ag NPs deposited on the CoMoO4 electrocatalyst. In addition, it demonstrated excellent electrocatalytic stability after a prolonged 25h amperometric test at - 1.3V versus RHE. It can be attributed to a synergistic effect between the Ag NPs and CoMoO4 rods. This study highlights the cooperation between Ag NPs on CoMoO4 components and provides new insight into the design of heterostructure as an efficient, stable catalyst towards electrocatalytic reduction of CO2 to CO, CH4, and C2H6 products.

Thermal-driven gigantic enhancement in critical current density of high-entropy alloy superconductors

The high-entropy alloy (HEA) superconductor, Ta1/6Nb2/6Hf1/6Zr1/6Ti1/6 (Ta–Nb–Hf–Zr–Ti), is systematically studied to examine changes in superconducting critical properties, critical temperature (Tc), critical current density (Jc), and upper critical field (Hc2), concerning thermal treatment conditions. Annealing condition affects Jc more significantly than Tc and Hc2, with a large improvement of flux pinning force density (Fp). The Jc of bare sample is reduced to 10 A cm–2 at an applied magnetic field of approximately 1.5 T, whereas the sample annealed at 550 °C for 12 h exhibits Jc > 100 kA cm–2 up to around 4 T. Furthermore, the Vickers hardness (HVIT) of the Ta–Nb–Hf–Zr–Ti HEA superconductor notably increases from ∼384 to 528 HVIT following a 24-h annealing at 500 °C. These results demonstrate that thermal annealing is a powerful process to optimize both the superconducting and mechanical properties of high-entropy alloy superconductors.

Enhancement of irreversibility field and critical current density of rare earth containing V0.60Ti0.40 alloy superconductor by cold-working and annealing

β-V1−xTix alloy superconductors are considered to be promising materials for high magnetic field applications. So far, attempts to improve the critical current density (JC) of β-V1−xTix alloys have shown limited success. Improving JC requires a controlled generation of defects. Similar to the V0.6Ti0.4-RE (RE = Gd, Y) alloys, RE = Ce, Dy and Nd are also immiscible in the V0.6Ti0.4 matrix. The superconducting transition temperature (TC), upper critical field (HC2), irreversibility field (HIrr), and JC increase with the RE addition. However, the tensile strength of V0.6Ti0.4-Gd alloy is observed to be significantly lower than that of V0.6Ti0.4 alloy. Cold-working is found to further improve the TC, HC2, HIrr, and JC of all the V0.6Ti0.4-RE alloys. Successive cold-working (with 50% reduction of thickness each time) and annealing (SCA) at 450∘C for 5 hrs is found to significantly improve the HIrr, and JC of V0.6Ti0.4-RE (RE = Gd, Ce) alloys. The tensile strength is also found to increase to about 60–70% of the V0.6Ti0.4 alloy after the third annealing. It is observed that α′ and ω phases form at the defect sites at various stages of cold-working and annealing. JC(H = 0) and HIrr are about 840 Amm−2 and 7 T respectively for the as-cast V0.6Ti0.4-RE alloys. Cold-working on the V0.6Ti0.4-RE alloys further improves the JC(H = 0) and HIrr to about 1250 Amm−2 and 8.45 T respectively. SCA increases the JC(H = 0) and HIrr to about 4000 Amm−2 (or more) and 9 T respectively, and the JC(7 T) to about 500 Amm−2 in V0.6Ti0.4-RE alloy at 4 K. We present a detailed description of the defect structure in these alloys and its role in pinning the magnetic flux lines, thereby improving the overall JC.

Local pH Change during CoMo-TiO2 Composite Electrodeposition and Alkaline HER Electrolysis

Alloys of Co-Mo and Co-Mo-P are of interest for their ability to enhance the hydrogen evolution reaction (HER)1-2 and adding TiO2 to the alloy surface can further enhance HER.3-5 To better understand the influence of TiO2 particles on the electrodeposition of Co-Mo and Co-Mo-P alloys and the resulting HER kinetics, electrodeposition was conducted on a copper mesh electrode in close proximity to a pH probe to measure the local change of pH. The deposit composition and the HER characterized. There was a significant enhancement in the HER exchange current density when TiO2 particles were present in the alloy, taking into account any changes in the surface area. The enhancement was associated with a local pH change. Without TiO2 particles present in the solid state, the local pH change follows an expected increase with time as hydrogen is evolved and the hydroxide ion is generated at the electrode surface. In contrast, when TiO2 particles were present at the surface and in the metal alloy matrix, the local pH initially decreases slightly and remains constant (Fig 1). The results suggest that the enhanced HER performance with TiO2 in the alloy composite electrocatalyst is a consequence of the buffering of the local pH. In contrast, during electrodeposition there is little change in the pH transient with and without having TiO2 particles in the electrolyte. C. C. McCrory, A. Jung, I.M. Ferrer, S.M. Chatman, J.C. Peters, T.F. Jaramillo, J Am Chem Soc, 137 (13) 4347 (2015).A. C. Thenuwara, L. Dheer, N. H. Attanayake, Q. Yan, U. V. Waghmare, D. R. Strongin, ChemCatChem. 10 4832-4837 (2018).A.R. Shetty, A.C. Hegde, Mater. Sci. Energy Technol. 1 (2) 97 (2018).C. Wang, Hubert K. Bilan, E. J. Podlaha, J. Electrochem. Soc. 166 (10) F661 (2019).C. Wang and E. J. Podlaha, J. Electrochem. Soc. 167 (13) 132502 (2020). Figure 1. Change of pH during HER on a Co-Mo electrodeposit at different HER electrolysis current densities. Figure 1

Visible-Light-Enhanced Hydrogen Evolution through Anodic Furfural Electro-Oxidation Using Nickel Atomically Dispersed Copper Nanoparticles.

A novel copper nanoparticle variant, denoted as Cu98Ni2 NPs, which incorporate Ni atoms in an atomically dispersed manner, has been successfully synthesized via a straightforward one-pot electrochemical codeposition process. These nanoparticles were subsequently employed as an anode to facilitate the oxidation of furfural, leading to the production of hydrogen gas. Voltammetric measurements revealed that the inclusion of trace amounts of Ni atoms in the nanoparticles resulted in a pronounced synergistic electronic effect between Cu and Ni. Consequently, a 43% increase in current density at 0.1 V was observed in comparison to pure Cu NPs. Importantly, when the Cu98Ni2 NPs were irradiated with visible light, a remarkable current density enhancement factor of 505% at 0.1 V was achieved relative to that of pure Cu NPs in the absence of light. This enhancement can be attributed to localized surface plasmon resonance induced by visible light, which triggers photothermal and photoelectric effects. These effects collectively contribute to the significant overall improvement in the electrocatalytic oxidation of furfural, leading to enhanced hydrogen evolution.

High-Stability RuNi/C Electrocatalyst for Efficient Hydrogen Oxidation Reaction in Alkaline Condition.

The Ru-based catalyst for hydrogen oxidation reaction (HOR) with remarkable activity and reliability at high potential range remains a formidable challenge. Herein, the RuNi/C nanoparticles are customized, in which NiRu alloy is tightly wrapped with a carbon layer, delivering 2.2-fold and 8.3-fold enhancement in kinetic current density than that of commercial Pt/C and Ru/C, respectively. Notably, the current density maintains 2.93mAcm-2 disk at 0.6 V vsRHE, which effectively improves the stability of Ru-based catalysts at high voltage. The NiRu alloy triggers electron redistribution between two metal elements and regulates the surface adsorption performance, coupled with a tightly wrapped outer carbon layer which is in situ formed with alloy as a good conductor of electronic and protection from the electrolyte. This work not only provides a novel electrocatalyst for efficient HOR with its potential for industrial application but also opens up a new avenue for designing highly active catalytic systems.

Enhancement of Critical Current Density of Nb3Al Superconductors by B Doping

Boron (B)‐doped Nb3Al superconductors are prepared by mechanical alloying and subsequent sintering process in this work. Then, the critical current density (Jc) of Nb3Al with different amounts of B doping is studied. In the results, it is shown that Jc performance of Nb3Al is improved obviously after B doping. The best Jc value obtained in this work is 2.2 × 104 A cm−2 (4.2 K, 5 T) for Nb3(Al0.9B0.1) sample. Furthermore, the mechanism of enhanced Jc performance for Nb3(Al0.9B0.1) sample is comprehensively explored. It is found that B doping can significantly enhance the grain connectivity of Nb3Al superconductor, and the active cross‐sectional area fraction values increase from 0.11 for the undoped sample to 0.34 for Nb3(Al0.9B0.1) sample. In addition, the lattice distortion caused by the interstitially dissolved B may also serve as flux pinning centers, which strengthens the flux pinning force of Nb3(Al0.9B0.1).

Synergistic lattice regulation of additive and interface engineering to realize high efficiency CsPbI2Br perovskite solar cell

The CsPbI2Br material has gained recognition as an exceptional candidate for both single- and multi- junction solar cells due to its remarkable thermal and light stability, along with its suitable band gap. However, despite these inherent advantages, CsPbI2Br perovskite solar cells (PSCs) still encounter significant energy losses, which impede the further enhancement of their efficiency. Although various approaches involving additives and interface engineering techniques improved device performance, the influence of these methods on the perovskite lattice is frequently overlooked. Herein, synergistic lattice regulation through the combination of potassium acetate (KAc) as electron interface layer and methylammonium chloride (MACl) as perovskite additive, was proposed. The MACl dopant effectively increases the crystallinity and grain size of CsPbI2Br film by retarding the crystallization rate of perovskite, resulting in the enhancement in short-circuit current density (Jsc) of PSCs. Unfortunately, unlike the behavior observed in inorganic–organic perovskites, the introduction of Cl‾ from MACl into the interstitial positions leads to lattice expansion in CsPbI2Br, resulting in reduced open-circuit voltage (Voc) and fill factor (FF). However, the incorporation of K+ replacing Cs+ effectively mitigates lattice distortion phenomena. Consequently, the CsPbI2Br PSCs, benefiting from the complementary effects of the MACl additive and KAc interfacial layer, exhibit an outstanding champion power conversion efficiency of 17.11 %. This research offers profound insights into the impact of ions introduced through additive and interface engineering on perovskite lattice stress.

Enhancement of critical current density and critical magnetic field of superconducting medium entropy alloy Nb2/5Hf1/5Zr1/5Ti1/5

We investigated the superconducting properties of medium entropy alloys (MEA) Nb2/5Hf1/5Zr1/5Ti1/5, synthesized by arc melting (AM) and powder metallurgical spark plasma sintering (SPS) methods. The samples exhibit superconducting transitions at Tc=7.99 K (AM) and 6.63 K (SPS) from the electrical resistivity measurements. The upper critical field at zero-temperature limit μoHc2(0) gives a relatively high value of 14.63 T (AM) and 11.68 T (SPS). The isothermal magnetic hysteresis of the SPS-MEA shows significantly enhanced vortex pinning, resulting in the enhancement of critical current density (Jc= 39,000 A/cm2) compared with the AM-MEA (Jc= 5,500 A/cm2) at 2 K (about seven times enhancement). The SPS-MEA shows a significant suppression of vortex avalanches compared with the previously reported SPS-HEA Ta1/6Nb2/6Hf1/6Zr1/6Ti1/6 superconductor. The SPS-MEA showed the secondary fishtail effect at a high magnetic field. There was a sizable specific heat jump ΔC(Tc)/γTc (3.3 for AM and 3.9 for SPS), significantly higher than the value of BCS prediction (1.43). Superconducting properties of MEA suggest the intermediate coupling of the electron-phonon coupling constant λ∼1 (λel−ph≃0.89 for AM and λel−ph≃0.78 for SPS) and the intermediate to strong coupling regime. The Kadowaki-Woods plot of the compounds is located on the line of the heavy fermion system. The Uemura plot indicates that the compounds are close to the conventional BCS superconductor. The contradictory property of strongly correlated and conventional BCS-type metallic superconductivity may come from the dirty superconducting regime with high Fermi velocity. Enhancing critical current density with significantly suppressed vortex avalanches on the SPS-MEA Nb2/5Hf1/5Zr1/5Ti1/5 compound suggests possible practical applications on the bulk superconductivity.

Nanostructure-induced inhibition of oxygen evolution and enhancement of methanol electrooxidation on engineered anodized brass

To capitalize the improved electrical contact feature, a self-supported hybrid binary/ternary copper and zinc oxides (i.e., ZnO–Cu2O and Cu2O–ZnO–CuO) nanostructures have been generated via a simple potentiostatic mode of anodaization on alpha brass in an alkaline medium. The catalyst nanostructuring i.e., wheat-grain-like to nanograss type structure has improved the mass transport, sluggish kinetics of methanol electrooxidation reaction process, and hindered the competitive oxygen evolution reaction (OER) of direct methanol fuel cell. The catalytic poisoning phenomenon has not been noticed due to two different reaction processes in two potential regions. Interestingly, a significant reduction in overpotential (η10mAcm−2OER−CH3OH) has been noticed for S125@A1 and S125@A2 samples i.e., 236 mV and 350 mV, respectively. The enhancement of current density has been explained through inductive circuit perspective. So, the present study provides a better insights to design and utilize non-precious metal/alloy based catalyst with hindered OER and enhanced methanol electrooxidation reaction activity.