Ternary Samples Research Articles

Experimental Investigation of Phase Equilibria in the Bi-Cu-Ge System

Abstract Phase diagram of the Bi-Ce-Ge ternary system has been investigated experimentally and thermodynamically extrapolated by using Pandat software. Experimental results were obtained using differential thermal analysis (DTA), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and X-ray powder diffraction (XRD) methods. Examined ternary samples belong to two isothermal sections at 400 and 600 °C as well as three vertical sections Bi-CuGe, Cu-BiGe, and Ge-BiCu. No ternary compound has been detected in the equilibrated samples from the selected isothermal sections. Based on the presented experimental data and available literature data, description of the ternary system has been developed. A reasonable agreement between the experimental data and the calculated phase equilibria was obtained. As an example, ternary Cu80Bi10Ge10 alloy was selected for solidification simulations according to Scheil and Lever Rule assumptions as well as for simulation of the total fraction of each solid at different temperatures, latent heat, and total heat.

Solution combustion synthesized TiO2/Bi2O3/CuO nano-composites and their photocatalytic activity using visible LEDs assisted photoreactor

In this work we have synthesized a series of binary TiO2/Bi2O3 and ternary TiO2/Bi2O3/CuO composites having different amount of Bi2O3 and CuO using the facile solution combustion approach. The characteristics of samples were identified using the X-ray diffraction (XRD), X- ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), photoluminescence (PL) spectroscopy and UV–vis diffuse reflectance spectroscopy (UVDRS) techniques. The Rhodamine B was taken as the organic pollutant to determine the photocatalytic efficiency of the materials under ultra-low power consumption visible LEDs as the source of light. The results demonstrate that the synthesized compounds possess good crystallinity and improved optical characteristics after introduction of Bi2O3 and CuO. The ternary sample having 10% of Bi2O3 and 10% of CuO showed the highest photoremoval of RhB which might be due of the formation of heterojunctions and improved optical characteristics towards the visible region. The beauty of the synthesized samples is their fast rate of removal of pollutant under visible LEDs which is beneficial for development of cost-effective water purification technique.

Cascade electron transfer in ternary CuO/α-Fe2O3/γ-Al2O3 nanocomposite as an effective visible photocatalyst

Highly efficient ternary heterojunction of CuO/α-Fe2O3/γ-Al2O3 was effectively fabricated by a facile and cost effective chemical route. The structural, chemical composition, morphology, optical and photocatalytic properties of as-prepared CuO/α-Fe2O3/γ-Al2O3 photo catalyst were compared to pristine and binary samples by various characterization. Existence of all the dominant peaks of CuO, α-Fe2O3 and γ-Al2O3 are noticeable in XRD spectrum of CuO/α-Fe2O3/γ-Al2O3 ternary photo catalyst which confirms the successful formation of the photocatalyst. SEM and HRTEM results revealed the spherical shape CuO nanoparticles with distorted α-Fe2O3 agglomerated plates which led to complete diffusion with γ-Al2O3. The band gap of ternary nanocomposite was found to be 1.9 eV elucidated by UV-DRS. Brunauer-Emmett-Teller (BET) analysis showed that as-fabricated ternary CuO/α-Fe2O3/γ-Al2O3 nanocomposite exhibited the porous structure with large surface area and small pore volume as compared to pristine γ-Al2O3.due to the unique ternary nanocomposite structure and synergistic effect among various components. The photocatalytic activity was examined by monitoring the deterioration of methyl orange under simulated solar light irradiation. CuO/α-Fe2O3/γ-Al2O3 exhibited superior photocatalytic efficacy as compared to CuO/γ-Al2O3 and α-Fe2O3/γ-Al2O3 binary and pure oxides of γ-Al2O3, CuO and α-Fe2O3. The marvelous photocatalytic activity of CuO/α-Fe2O3/γ-Al2O3 ternary nanocomposite samples can be ascribed to their close contact, strong interfacial hybridization and proficient charge transfer capacity. The electrochemical studies such as linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were carried out to explore the charge transfer behavior and support the high photo activity of ternary nanocomposite CuO/α-Fe2O3/γ-Al2O3. LSV measurements manifested that CuO/α-Fe2O3/γ-Al2O3 exhibited 4.3 folds higher current density than bare γ-Al2O3 which confirmed the faster electron transfer from CuO to γ-Al2O3 via mediated α-Fe2O3 through the interfacial potential gradient in conduction band. Cyclic voltammetry (CV) results showed that pair of anodic and cathodic peaks in CuO/α-Fe2O3/γ-Al2O3 appeared which affirm the efficient increase in photo-induced e−/h+ separation and suppress recombination rate of electron-hole pair. This work demonstrated that CuO/α-Fe2O3/γ-Al2O3 ternary nanocomposite is found to be a promising candidate as an efficient adsorbent for organic dye removal from waste water.

Assembly of mixed Bi4V1.4Nb0.6O11 phase and g-C3N4 photoactive material over rGO: Enhanced organic model pollutants removal under sun light irradiation

A novel efficient Bi4V1.4Nb0.6O11/g-C3N4 over the rGO ternary composite has been prepared by the cost effect method for diverse model organic molecule pollutants removal. The synergistic interaction between the materials has been investigated by the several characterization tools. The intimate contact between the ternary materials was explored by HRTEM analysis. The photo-catalytic degradation rate of the obtained ternary composite samples was examined for the removal of the MB dye and photo-reduction of the 4-Nitrophenol molecules in direct sun light irradiation. More interestingly, photo removal efficiency for MB molecule was achieved 93 % and the photo-reduction efficiency was 97 % for 4-Nitrophenol solution. The complete mineralization of the MB and 4-NP was further assessed by the LC-MS analysis, which shows the successful destruction of toxic molecules. The Z- scheme charge carrier transfer between the active materials was proposed and which is evidenced by the free radical trapping experiments and ESR trapping experiments.

Investigation of Acetone Vapour Sensing Properties of a Ternary Composite of Doped Polyaniline, Reduced Graphene Oxide and Chitosan Using Surface Plasmon Resonance Biosensor.

This work reports the use of a ternary composite that integrates p-Toluene sulfonic acid doped polyaniline (PANI), chitosan, and reduced graphene oxide (RGO) as the active sensing layer of a surface plasmon resonance (SPR) sensor. The SPR sensor is intended for application in the non-invasive monitoring and screening of diabetes through the detection of low concentrations of acetone vapour of less than or equal to 5 ppm, which falls within the range of breath acetone concentration in diabetic patients. The ternary composite film was spin-coated on a 50-nm-thick gold layer at 6000 rpm for 30 s. The structure, morphology and chemical composition of the ternary composite samples were characterized by FTIR, UV-VIS, FESEM, EDX, AFM, XPS, and TGA and the response to acetone vapour at different concentrations in the range of 0.5 ppm to 5 ppm was measured at room temperature using SPR technique. The ternary composite-based SPR sensor showed good sensitivity and linearity towards acetone vapour in the range considered. It was determined that the sensor could detect acetone vapour down to 0.88 ppb with a sensitivity of 0.69 degree/ppm with a linearity correlation coefficient of 0.997 in the average SPR angular shift as a function of the acetone vapour concentration in air. The selectivity, repeatability, reversibility, and stability of the sensor were also studied. The acetone response was 87%, 94%, and 99% higher compared to common interfering volatile organic compounds such as propanol, methanol, and ethanol, respectively. The attained lowest detection limit (LOD) of 0.88 ppb confirms the potential for the utilisation of the sensor in the non-invasive monitoring and screening of diabetes.

Formulation of Piperine Ternary Inclusion Complex Using β CD and HPMC: Physicochemical Characterization, Molecular Docking, and Antimicrobial Testing

The present study was designed to evaluate the effect of hydroxyl propyl methyl cellulose (HPMC) on the complexation efficiency and dissolution of piperine (PPR) and β cyclodextrin (β CD) complex. The binary and ternary inclusion complexes were prepared using solvent evaporation and microwave irradiation methods. The samples were further evaluated for physicochemical evaluation, morphology, antimicrobial, and antioxidant activities. The binary and ternary samples showed high stability constant (Ks) value and complexation efficiency (CE). The dissolution study results revealed marked enhancement in the release of the binary inclusion complex and ternary inclusion complex compared to pure PPR. Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR), and molecular docking results confirm the complex formation. X-ray powder diffractometry (XRD) and scanning electron microscopy (SEM) data revealed modification in the structure of PPR. 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and antimicrobial results showed enhanced activity in the PPR complex in comparison to pure PPR. In conclusion, a remarkable enhancement in dissolution, antioxidant and antimicrobial activities were attained due to marked improvement in solubility through complexation of PPR with HPMC/β CD.

Hybrid polymer matrix composite (UHMWPE‐HPMC) as solid particle erosion resistant coating for sharp pipe elbows using numerical simulation and experimental analysis

AbstractA hybrid polymer matrix composite coating, resistant to solid particle erosion inside sharp elbows, consisting interlocking chains of molecules with the ability to deflect the surface impact stress and to uniformly distribute stresses along the hard‐ceramic reinforcement mixture surface was developed. Formulated mixture of ceramic reinforcement particles mixtures (alumina, tungsten carbide, and silicon carbide) with polymer coupling agents; to increase adhesion to the metal surface, led to 600–700 HVN in ternary and 500–550 HVN in binary mixtures. This behavior coincides with high shear strength of 70–76 MPa, Young's and shear modulus of 8.86 and 13.4 GPa in ternary 15%Al2O3‐5%WC‐10%SiC, respectively. The low erosion weight loss of 0.1% and small coefficient of friction near 0.18 indicates the significant wear resistance of the ternary sample. The electron microscopic micrographs determined the dense smooth coating surfaces with adhesive interfaces with the substrate.

Facile assembly of BiVO4/protonated g-C3N4/AgI with a novel dual Z-scheme mechanism for visible-light photocatalytic degradation of Rhodamine B

Constructing Z-scheme photocatalyst is an effective strategy to achieve efficient photogenerated electron-holes separation and retain its outstanding redox ability simultaneously. In this work, a novel ternary BiVO4/protonated g-C3N4/AgI photocatalyst with a double Z-scheme mechanism is successfully constructed by electrostatic self-assembly method loading of BiVO4 onto protonated g-C3N4 and subsequently via an in situ precipitation route. Using Rhodamine B (RhB) as the target of elimination, BiVO4/protonated g-C3N4/AgI displays excellent photocatalytic performance with the 94.67% removal after 60-min visible light irradiation. The photodegradation rate constant of RhB is 0.04963 min−1, which faster than pristine BiVO4 (0.0004 min−1), BiVO4/protonated g-C3N4 (0.0209 min−1) and BiVO4/AgI (0.0317 min−1), respectively. Such enhancement in photocatalytic activity is correlated to improved light absorption, faster charge carrier separation and transportation as well as more powerful redox ability originating from the formation of double Z-scheme heterostructure. Also, the as-prepared ternary sample exhibits high stability after four cycles of the photodegradation reaction. Furthermore, the possible photocatalytic mechanism of BiVO4/protonated g-C3N4/AgI is also proposed. Therefore, we believe that this work can provide insights into the understanding the significant role of design and synthesis the double Z-scheme in semiconductor heterostructure system for environmental remediation.

Evolution of dielectric relaxation under elevated electric field of polypropylene-based films

Extensive research has been performed on polypropylene (PP) based films focusing on the improvement of energy storage performance for power capacitor application. The increase of energy storage density was often accompanied with the rising of dielectric losses, especially under high electric field. The gap of electric field between the laboratorial level (0.006 ∼ 0.02 kV mm−1) and practical working condition of capacitor (more than 50 kV mm−1) could be thousands of times, which was often neglected in most research. In the present paper, the systematical study of the dielectric relaxation processes on elevated electric field was carried out on neat PP and three typical kinds of PP-based films, i.e. PP/ZrO2 nanocomposite, PP/maleic anhydride grafted polypropylene (PP-g-MAH) blends, and PP/PP-g-MAH/ZrO2 ternary nanocomposite with the energy storage density 17.3% higher than neat PP. The frequency dependence of dielectric losses under elevated field showed that even under 20 kV mm−1, the loss of ternary PP increased little, while the losses of the binary sample increased much more. The space charge test as well as the DC conductivity test revealed the origin of increased dielectric loss, which was the consequence of extrinsic ion hopping stimulated by the elevated field. Meanwhile, in the ternary PP/PP-g-MAH/ZrO2 nanocomposite, the activation energy of ion hopping was greatly improved due to the enhanced interaction between molecules, so the dielectric loss under high field, the space charge accumulation and the DC conductivity of the ternary sample all showed an extremely low level. This study has directive significance for the application of nanocompositse.

Colour tunable co-evaporated CdSxSe1-x (0 ≤ x ≤ 1) ternary chalcogenide thin films for photodetector applications

Cadmium Sulfoselenide CdSxSe1-x (0 ≤ x ≤ 1) films were grown by thermal co-evaporation of source materials, CdS and CdSe, taken in the stoichiometric ratio. Systematic shift in the position of X-ray diffractogram (XRD) peak and optical absorption edge have confirmed the change in structural and optical properties as x varied from 0 to 1. Further, photoluminescence (PL) spectra revealed that ternary system has a minimum defect, which is the basic requirement for device applications. The Raman and X-ray photoelectron spectroscopy (XPS) studies have given concurrent results revealing the chemical states of the ternary samples. Detailed analysis of XPS has shown incorporation of oxygen in minor fraction, which proved to help in improving the photoresponse. Electrical study has shown that the electrical properties can varied by changing the composition. All the samples have exhibited n-type conductivity with carrier concentration in the range 1014 to 1015 cm−3. Finally, photoresponse study showed that sample with x = 0.2 is best suitable for photodetector, where the device can be operated over entire visible range.

Growth and characterization of InGaAs/InAsSb superlattices by metal-organic chemical vapor deposition for mid-wavelength infrared photodetectors

Abstract InGaAs/InAsSb superlattices (SLs) were grown on InAs substrates by metal-organic chemical vapor deposition (MOCVD) for potential applications in mid-wavelength infrared photodetectors. Three In1-xGaxAs/InAs0.73Sb0.27 ternary SL samples, with x = 0.2, 0.25, and 0.3, were grown and investigated by X-ray diffraction, atomic force microscopy and photoluminescence. Excellent structural qualities were achieved with lattice mismatches of less than 0.15% and atomically smooth surfaces with a roughness of only 0.18–0.19 nm. Strong photoluminescence (PL) emissions were observed at around 3.7 μm at 77 K. Besides, Varshni fitting indicates the temperature-sensitive parameter α in the InGaAs/InAsSb SLs is only half of that in InAs/InAsSb SLs, making them suitable for high temperature operation.

Solid-state phase equilibria in the Er-Nd-Fe ternary system at 1073 K

The solid state phase equilibria in the ternary Er-Nd-Fe system at 1073 K in all the composition ranges were investigated using the experimental results of the X-ray powder diffraction analysis (XRD) as well as those obtained from the Scanning electron microscopy (SEM) equipped with Energy dispersive spectroscopy (EDS). The binary systems Er–Fe, Er–Nd and Nd-Fe were investigated prior to the study of the ternary one. Six binary compounds were identified to exist at this isothermal sectionss at 1073 K namely: ErFe2 (Fd3¯m-MgCu2 structure type), ErFe3 (R3¯m-PuNi3 structure type), Er6Fe23 (Fm-3m-Th6Mn23 structure type), Er2Fe17 (P63/mmc-Th2Ni17 structure type), Nd2Fe17 (R3¯m-Th2Zn17 structure type), and δ-NdEr (R3¯m-Sm structure type). No new ternary compounds were found in all investigated ternary alloy samples. The phase relations are governed by seven three-phase regions, sixteen two-phase regions and nine single-phase regions, as well as a small liquid area in the Nd-rich region. At 1073 K, we have observed that the highest solubility of Nd in ErFe2 is about 16.6 at. % Nd, while the Er1−xNdxFe3 solid solution based on binary ErFe3 extends up to 7.5 at. % Nd. The XRD and the SEM/EDS analyses show that there is no miscibility of Nd in Er6Fe23. The pair of the binary compounds Er2Fe17 and Nd2Fe17 extend through the ternary system parallel to the Nd-Er edge. The maximum homogeneity range of the Er2−xNdxFe17 solid solution reaches 5.3 at. % Nd, while that of the Nd2−xErxFe17 solid solution is about 1.6 at. % Er. In the Er-Nd binary system, the maximum solid solubility of Nd in Er is about 38.4 at. % Nd, and the solubility limit of Er in Nd is about 29.8 at. % Er.

Packing void ratios of very dense ternary mixtures of similar ellipsoids

The paper presents a numerical study on the void ratio of a ternary mixture of similar ellipsoids. The effect of particle size distribution on the void ratio was investigated through samples of various volume fractions of large, medium, and small particles. The particle size ratio of large, medium, and small particles is 16:4:1. The ratio between the major and minor axes of an ellipsoid is 1.5. Thirty-nine very dense ternary samples and sixteen samples of very dense binary samples have been created using the discrete element method. The void ratios of the ternary samples are similar to those of the round washed sands of broader particle sizes. The void ratios of these numerical samples were estimated by an existing model of ternary mixtures of spheres without adjusting the constants to examine the effect of particle shape. A novel phenomenological model is suggested for the void ratio of a ternary mixture. The model is applied to the ternary mixture of similar ellipsoids, and the ternary mixture of round washed sands. A good agreement is observed in both cases.

Phase Equilibria in the Ce-Pr-Fe System at 600 °C

The phase relationships of the Ce-Pr-Fe ternary system at 600 °C were experimentally investigated using equilibrated alloys and diffusion junction samples with the use of electron probe microanalysis, x-ray diffraction, and scanning electron microscopy. The isothermal section of the Ce-Pr-Fe system at 600 °C consists of 7 single-phase, 11 two-phase, and 5 three-phase regions. No ternary compound was found. The PrFe2 phase was observed in both ternary alloys and diffusion samples at normal pressure. The solid solubility of Ce in PrFe2 and Pr2Fe17 is 1.76 and 3.75 at.%, respectively. The solid solubility of Pr in CeFe2 and Ce2Fe17 is 13.21 and 0.77 at.%, respectively.

Mechanical Strength Evaluation of the Internal Matrix Reinforced Nb3Sn Multifilamentary Wires Using Cu–Sn–In Ternary Alloy Matrix

We investigated the simple internal reinforcement method using special reinforcement ternary bronze alloy matrix on the bronze processed Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn wire. The Cu-Sn-Zn ternary alloy matrix was transformed to the (Cu, Zn) solid solution after Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn synthesis based on the solid solution strengthening mechanism. For the further mechanical strength improvement, we focused on the Indium (In) as the more effective solute element for the “internal matrix strengthening”, and succeeded to fabricate the bronze processed Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn multifilamentary wire using various Cu-Sn-In-(Ti) ternary alloy matrices. Changes of the Vickers hardness before and after Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn synthesis and the transport critical current (Ic) under the uniaxial tensile deformation were evaluated. Vickers hardness of the matrix after Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn synthesis on the Cu-Sn-In ternary alloy matrix samples was higher compared with the conventional bronze and the Cu-Sn-Zn ternary matrix samples. On the other hand, the tensile stress obtained to the maximum peak Ic value on the Cu-Sn-In ternary alloy matrix sample was estimated to approximately 265 MPa, and this value was much higher than those of the Cu-Sn-Zn ternary matrix and conventional bronze processed samples. We found that the In element would become more attractive solute element than Zn element for the internal reinforcement ternary matrix.

Predicting densities and elastic moduli of SiO2-based glasses by machine learning

Chemical design of SiO2-based glasses with high elastic moduli and low weight is of great interest. However, it is difficult to find a universal expression to predict the elastic moduli according to the glass composition before synthesis since the elastic moduli are a complex function of interatomic bonds and their ordering at different length scales. Here we show that the densities and elastic moduli of SiO2-based glasses can be efficiently predicted by machine learning (ML) techniques across a complex compositional space with multiple (>10) types of additive oxides besides SiO2. Our machine learning approach relies on a training set generated by high-throughput molecular dynamic (MD) simulations, a set of elaborately constructed descriptors that bridges the empirical statistical modeling with the fundamental physics of interatomic bonding, and a statistical learning/predicting model developed by implementing least absolute shrinkage and selection operator with a gradient boost machine (GBM-LASSO). The predictions of the ML model are comprehensively compared and validated with a large amount of both simulation and experimental data. By just training with a dataset only composed of binary and ternary glass samples, our model shows very promising capabilities to predict the density and elastic moduli for k-nary SiO2-based glasses beyond the training set. As an example of its potential applications, our GBM-LASSO model was used to perform a rapid and low-cost screening of many (~105) compositions of a multicomponent glass system to construct a compositional-property database that allows for a fruitful overview on the glass density and elastic properties.

A review on effect of alloying elements and heat treatment on properties of Al − Sn alloy

Aluminum (Al) –Tin (Sn) alloys are potential lead free bearing materials, widely used in automobile and marine applications. These alloys possess good fatigue strength, seizure resistance, corrosion resistance and embedability properties. However, properties of Al − Sn alloy have to be modified to suit for engineering applications. In this paper we present a review on characterization of mechanical and tribological properties of Al − Sn alloys subjected to heat treatment (Annealing) and also effect of addition of alloying elements such as Bi, Mg, Pb, Nano Si and Nano Gr. The review suggests that heat treated alloys exhibited better mechanical properties whereas ternary alloyed samples showed improved tribological properties.

Thermodynamic description, hardness and electrical conductivity of the Bi–Ni–Zn system: Experiment and modeling

Selected ternary systems are chosen due to the significant interest of nickel alloys in the different industry such as electronic, chemical, automotive, marine etc. Chosen ternary system up to this paper has not been studied. The ternary system Bi–Ni–Zn has been experimentally and analytically tested. Temperatures of phase transformation were determined by differential thermal analysis (DTA) on 12 ternary samples. Obtained results by DTA test were compared with calculated vertical sections Bi–NiZn, Ni–BiZn and Zn–BiNi. Hardness and electrical conductivity were measured for some alloys. By using experimental results of hardness and electrical conductivity tests, mathematical model has been proposed for calculation of those properties along all composition ranges. Composition of alloys and phases in alloys annealed at 400 and 700 °C were determined by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS). Obtained results by EDS were compared with calculated isothermal sections at 400 and 700 °C. X-ray powder diffraction (XRD) tests were used for phase identification in all ternary samples. Used analytical method was Calphad method. Calculation of phase diagrams (three vertical sections and two isothermal sections) was performed by using thermodynamic parameters for constitutive binary systems. Good agreements between calculated phase diagrams and experimental data have been reached without introducing ternary thermodynamic parameters. Based on this conclusion liquidus projection and invariant reaction were calculated without additional experimental tests.

Achieving electrical insulation, high thermal conductivity and high fracture toughness in polyamide 6/carbon nanofiber composites through the interfacial welding effect of elastomer

Interfacial interaction exhibits important role in determining the performance of polymer composites, especially at high filler content. In this work, illuminated from the braze welding technology that is applied to joint different metals using the welding stick with relatively high plastic deformation ability or high toughness, a new concept of ‘interfacial welding’ was proposed to engineer the strong interfacial interaction of the thermally conductive composites. A commercial elastomer, i.e. anhydride-modified ethylene-based copolymer (AEC), was incorporated into the polyamide 6 (PA6)/carbon nanofibers (CNFs) composites. Due to the presence of the insulating AEC and the stronger interfacial affinity between CNFs and AEC, the ternary PA6/CNF/AEC composite samples showed largely enhanced electrical resistance and comparable thermal conductivity compared with the binary PA6/CNF composite samples. Specifically, largely enhanced fracture toughness was achieved for the ternary composite samples. The concept of ‘interfacial welding’ may be extended to fabricate the other composites with excellent comprehensive performances.

Oxidized impurity in transition metal nitride for improving the hydrogen evolution efficiency of transition metal nitride-based catalyst

Transition metal nitrides (TMNs)-based catalyst as promising alternative for precious metal-based catalyst in hydrogen evolution have gained ever increasing research attention. However, the metastable nature of TMNs often results in the inevitable formation of metallic, oxidized and hydroxide impurities during fabrication. The effects of the inevitable impurities over TMNs in hydrogen evolution reaction are still unclear. Herein, choosing Ni3N as a typical example, the effect of oxidized impurity in transition metal nitride for hydrogen evolution has been systematically investigated. The metal oxdie-metal nitride heterojunction which has been in-situ created by calcinations process exhibits obviously improved performance in boosting hydrogen evolution efficiency of semiconductors as compared to metal nitride by forming Z-scheme pathway. Besides, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) measurements demonstrate the formation of reductive defects on the surface of semiconductors created by ammonia treatment which also boost the hydrogen evolution efficiency. Therefore, the optimal ternary sample exhibits the highest hydrogen evolution rate (151.5 μmol g−1 h−1) under solar light irradiation, which is about 54 times higher than that of pure sample.