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The construction and assessment of an effective, cost-efficient anode catalyst for methanol oxidation reactions (MOR) are crucial in direct methanol fuel cells (DFMC) applications. This work unveils a quick, simple, yet effective method for synthesizing poly(aniline-co-pyrrole) using the "chemical oxidative polymerization" technique and creates an affordable and stable anode catalyst for DMFC applications. The chemical oxidative polymerization approach was employed to copolymerize aniline and pyrrole with incorporation of nickel, and the electrocatalyst showcased remarkable activity towards methanol oxidation reaction (MOR). Physiochemical characterizations such as scanning electron microscopy, FT-infrared spectroscopy, Raman spectroscopy, and thermogravimetric analysis were performed to validate the incorporation of transition metal nickel into the copolymerized conducting polymers (aniline-co-pyrrole), abbreviated as PANiPPy. Electrochemical techniques like cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy (EIS) were used to investigate the capability of the electrocatalysts to oxidize methanol in alkaline conditions. The electrode material NiPANiPPy displayed a higher oxidation current density 280.60 mA/cm2 from the cyclic voltammogram of the electrocatalysts in 1 M KOH + 1 M methanol compared to the other synthesised electrocatalysts since nickel provides a low onset potential while the copolymers PANiPPy provide good conductivity and mechanical stability. Moreover, NiPANiPPy exhibits the lowest current rate loss and a substantially higher current density among them after 3600 s with the highest current density of 100 mAcm−2. NiPANiPPy was also observed to have the lowest solution resistance with 0.8 Ω compared to other electrocatalysts in EIS spectra. Thus, the synthesized electrocatalysts has potential applications as an enhanced anode electrode for DMFC. [ABSTRACT FROM AUTHOR]

Activated carbon with appreciable level of porosity and honeycomb like structure was synthesized through simple KOH activation of biochar obtained from Caladium tricolor leaves. The synthesized activated carbon was characterized for morphological and structural characteristics using various techniques. The material possesses an enhanced BET surface area (SBET) of 1429m2/g with significant microporous texture. XPS data revealed the presence of Nitrogen as the inherent dopant in the material which enhance electrochemical and adsorption perfmance. The activated carbon has been employed as electrode material for electrical double layer type capacitance (EDLC) type supercapacitor which showed promising specific capacitance of 428 F/g at a current density of 1 A/g. Cyclic stability studies revealed a retention of capacitance of 98% for 5000 cycles. Further, adsorption studies were conducted using Furazolidone drug and the adsorption efficiency was found to be 90% following Langmuir isotherm model. Kinetic studies revealed that the adsorption follows pseudo-second order kinetics. The material also investigated for ORR activity which showed notable results which can be further improved to be employed as a metal free Oxygen reduction reaction (ORR) catalyst. [ABSTRACT FROM AUTHOR]

In this work, the Metal Inert Gas (MIG) welding process is used for depositing the Inconel 718 over the base substrate of Stainless steel 321. The optimal welding conditions like 50% overlap, Direct Current (DC) plus mode with a pulse on time (1–5 s), frequency (0.25–1 Hz), peak current (120 A), base currents (60% of peak current), and speed (150–350 mm/min) are used for the successful hard-facing. The quality of the hard-facing is analyzed by conducting microstructural studies, tensile tests, microhardness, wear behavior, and electrochemical studies. Post-processing for wear and electrochemical studies is done by Scanning Electron Microscope SEM–EDX analysis. Microstructural studies revealed the presence of columnar dendrites and equiaxed at the top of the hard-faced layer. Hard-faced layer depicts the highest ultimate tensile strength of 772 N/mm2 with an elongation of 31.50% due to the support of Nickel components. The presence of the voids and dimples is identified from the SEM fractography. The maximum hardness value of 212 HV 0. 5 is measured at the top of the hard face layer. The microhardness of the hard-faced layer increased by 17.77% higher than its base substrate. Because of the hard precipitates and higher microhardness made by the weld thermal cycle, the hard-face layer showed maximum Co-efficient of Friction (CoF) of 0.540. Debris and grooves are found with the SEM examination of the wear specimens. Higher impedance offers better corrosion resistance to the hard-faced layer Inconel 718. The EDX analysis confirms the presence of Chromium, Molybdenum, and Niobium contents at the hard-faced layer. These elements silently support better corrosion resistance compared to the base substrate of Stainless steel 321. [ABSTRACT FROM AUTHOR]

Manganese and Nickel oxides were electrodeposited onto Nickel foam by potentiodynamic (10, 25 and 50 cycles), potentiostatic and galvanostatic modes and the effects of different electrodeposition techniques on the elemental compositions and their supercapactive behaviour were studied to optimise the most appropriate electrodeposition technique for supercapacitor application. The structural properties, morphology and elemental analysis were studied by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) accompanied by Energy-Dispersive X-Ray Analysis (EDX). The electrodes’ functional groups were analysed via Fourier Transform-Infrared Spectroscopy (FT-IR). Their electrochemical supercapactive performance were assessed by calculating the areal capacitance from cyclic voltammograms (CV), from Galvanostatic charge-discharge Curves (GCD), and their behaviour was accessed by Electrochemical impedance spectroscopy (EIS) analyses in 0.1 M KOH. The electrochemical results specified among the different electrode MN10, MN25, MN50 (potentiodynamic electrodeposition), MNCA (electrodeposition via chronoamperometry) and MNCP (electrodeposition via chronopotentiometry); MN25 delivered the highest areal capacitance areal capacitance 256.08 F cm−2, with energy density 12.81 Wh cm−2 and power density 150.71 W cm−2 with the capacitance retention percentage of 80.5% at 5 Acm−2 after 5000 cycles. [ABSTRACT FROM AUTHOR]

Nanostructured Zinc oxide (ZnO) materials have attained exciting research interests among various metal oxide nanoparticles due to their unique features. Thus, the scope of applications for ZnO nanoparticles (ZnO NPs) is vast and efficient. The current study demonstrates a simple and environmental-friendly approach for the synthesis of ZnO NPs using the extract of the Scoparia Dulcis. Scoparia Dulcis is a common medicinal plant in Kerala (India) that is traditionally used for its medicinal properties. Morphological characterizations of the as-synthesized ZnO NPs were evaluated using X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and field-emission scanning electron microscopy (FESEM). The results revealed that ZnO NPs showed pebble-like morphology and possessed an average particle size of ~ 20 nm. Further, antibacterial and antifungal activities of as-prepared ZnO NPs were investigated against E. coli, Staphylococcus aureus, as well as Candida albicans, and Aspergillus niger, respectively, using the agar-well diffusion method. The results revealed that the prepared ZnO NPs shows excellent antimicrobial activity against the examined microorganisms. Moreover, the antioxidant activity of the as-synthesized ZnO NPs was evaluated using the DPPH assay, which indicated an excellent IC50 value of 1.78 μg/mL that shows high antioxidant activity. All these results proved that the S. dulcis plant extract-mediated synthesis method is a simple, low-cost, eco-friendly procedure for preparing efficient ZnO NPs for biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, a Ru-doped Ni pellet-type catalyst was prepared to produce hydrogen via steam methane reforming (SMR). A small amount of Ru addition on the Ni catalyst improved Ni dispersion, thus affording a higher catalytic activity than that of the Ni catalyst. During the daily startup and shutdown (DSS) operations, the CH4 conversion of Ni catalysts significantly decreased because of Ni metal oxidation to NiAl2O4, which is not reduced completely at 700 °C. Conversely, the oxidized Ni species in the Ru–Ni catalyst can be reduced under SMR conditions because of H2 spillover from the surface of Ru onto the surface of Ni. Consequently, the addition of a small quantity of Ru to the Ni catalyst can improve the catalytic activity and stability during the DSS operation. [ABSTRACT FROM AUTHOR]

A novel Poly(vinylidene fluoride)-Melamine (PVDF-Melamine) nanofiber scaffold has been constructed through electrospinning method. The fabricated electro spin nanofibers were subjected to further morphological and chemical characterization i.e., x-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field emission Scanning Electron Microscope (FESEM) and x-ray photoelectron spectroscopy (XPS). Heat response behavior and degree of crystallinity of the nanofibers were examined through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Mechanical strength and electrochemical behavior of the nanofibers were also analyzed. The electro spun PVDF-Melamine composite exhibited appreciable nanofiber morphology with average diameter ranging of 508.8 nm. FTIR and XRD results also confirmed the successful incorporation of melamine within the PVDF matrix. The PVDF-Melamine nanofibers possess superior mechanical strength compared to pristine PVDF nanofibers which is evident from the higher young's modulus of 12.6 MPa and enhanced tensile strength of 2.63 MPa for the PVDF-Melamine nanofiber. This work provides an approach to fabricate electro spun PVDF-Melamine nanofibers with superior mechanical strength which can be a promising material for real time applications. [ABSTRACT FROM AUTHOR]

In this present work, a comparatively less expensive and more abundant nickel (Ni) supported on poly(diphenylamine) (PDPA) has been utilized as a potential substitute to noble metal catalyst for methanol oxidation. The hybrid catalyst of nickel over PDPA matrix (Ni@PDPA) was successfully synthesized via ultrasonication method. Average size of nickel catalyst was identified to be 100–200 nm and was analyzed through field emission scanning electron microscopy. The as synthesized Ni@PDPA hybrid catalyst crystalline natures were characterized through X-ray diffraction studies. The nature of bonding was analyzed through Fourier transform-infra red spectroscopy. Ni@PDPA hybrid catalyst gave a peak current density of 1.93 mA/cm2 at 0.84 V during methanol oxidation reaction. The results obtained proved that Ni@PDPA hybrid catalyst serves to be an efficient electrocatalyst for the application of direct methanol fuel cell. [ABSTRACT FROM AUTHOR]

Polydiphenylamine (PDPA) finds many applications as a conducting polymer due to its unique properties. Herein, we report a facile synthesis of PDPA nanoparticles (PDPA NPs) and PDPA nanorods (PDPA NRs) via microwave and ultrasonication approach towards energy storage application. The morphology of synthesized PDPA nanostructures was captured through scanning electron microscope. The crystallinity and molecular vibrational studies of synthesized PDPA nanostructures was analysed through X-ray diffraction studies and Fourier-Transform infrared spectroscopic technique. Also, the electrochemical properties of the fabricated PDPA nanoelectrodes were characterized through cyclic voltammetry, impedance and galvanostatic charge–discharge studies. The specific capacitance of PDPA-NPs and PDPA-NRs using cyclic voltammetry curves and galvanostatic charge–discharge studies was found to be 97 F/g and 156 F/g at 25 mV/s scan rate and 166 F/g and 194 F/g at 10 mA/g current density, respectively. PDPA-NPs and PDPA-NRs exhibit remarkable cyclic retention and stability over 1000 cycles (83% and 85%, respectively). The columbic efficiency of PDPA-NPs and PDPA-NRs was found to be 96% and 98%, respectively. These results indicate that the synthesized PDPA nanostructures are potentially worthy to be used as an electrode material and would be used in future energy storage systems. [ABSTRACT FROM AUTHOR]

Field effect transistor (FET)‐based nanoelectronic biosensor devices provide a viable route for specific and sensitive detection of cancer biomarkers, which can be used for early stage cancer detection, monitoring the progress of the disease, and evaluating the effectiveness of therapies. On the road to implementation of FET‐based devices in cancer diagnostics, several key issues need to be addressed: sensitivity, selectivity, operational conditions, anti‐interference, reusability, reproducibility, disposability, large‐scale production, and economic viability. To address these well‐known issues, significant research efforts have been made recently. An overview of these efforts is provided here, highlighting the approaches and strategies presently engaged at each developmental stage, from the design and fabrication of devices to performance evaluation and data analysis. Specifically, this review discusses the multistep fabrication of FETs, choice of bioreceptors for relevant biomarkers, operational conditions, measurement configuration, and outlines strategies to improve the sensing performance and reach the level required for clinical applications. Finally, this review outlines the expected progress to the future generation of FET‐based diagnostic devices and discusses their potential for detection of cancer biomarkers as well as biomarkers of other noncommunicable and communicable diseases. [ABSTRACT FROM AUTHOR]

In this work, a novel co-deposited nano spherical polydiphenylamine-palladium supported graphitic carbon nitride (GCN/PDPA/Pd NS) nanohybrid was fabricated via the in-situ one-pot electrochemical co-deposition method. The GCN/PDPA/Pd NS nanohybrid electrode was characterized by morphology studies, which found that the average diameter of the PDPA/Pd nanospherical size is 250 nm over the graphitic carbon nitride nano matrix as well as elemental composition, structural and vibrational spectra also observed through FESEM, EDX, Mapping, and XRD, FT-IR studies. The electrochemical characterizations of the GCN/PDPA/Pd NS electrocatalyst were studied using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopic techniques. The fabricated GCN/PDPA/Pd NS–modified electrode shows significant electrocatalytic activity, lower oxidation potential (− 0.15 V), high stability, and longevity (1800s) towards methanol oxidation reaction (MOR) in an alkaline medium. The fabricated GCN/PDPA/Pd NS electrocatalyst is a significant anode catalyst for the direct methanol fuel cell application. [ABSTRACT FROM AUTHOR]

C1‐selective deuteration of aromatic aldehydes is of great importance for isotopic labeling and for improving the characteristics of drug molecules. Due to the recent increase in the use of deuterated pharmacological drugs, there is a pressing need for synthetic procedures that are efficient to produce deuterated aromatic aldehyde analouges. Deuterium labeling approaches are typically used as an effective tool for researching pharmaceutical absorption, distribution, metabolism, and excretion (ADME). Furthermore, deuterium‐labeled pharmaceuticals are intended to increase therapeutic effectiveness and reduce side effects by extending the half‐life of drug response. In the last few years, several catalytic or non‐catalytic methods have been developed to synthesize deuterated aromatic aldehydes. In this concern, we offer a brief overview of the various synthetic strategies and practical methods for the formyl‐selective deuterium labeling of aromatic aldehydes using different deuterium sources. [ABSTRACT FROM AUTHOR]

A covalently functionalized-multiwalled carbon nanotubes (f-MWCNTs) with 2-aminothiophenol (2ATP) supported cerium oxide nanoparticles (CeO2 NPs) adsorbed on selenium nanoparticles (Se NPs) (MWCNT(SH)/CeO2@Se NPs) was prepared using a simple chemical route and utilized for the inactivation of Gram-positive/negative bacteria and fungus. In this investigation, a mixture of cerium nitrate and selenium dioxide precursor salts in the presence of MWCNT(SH) in p-toluene sulfonic acid medium (0.5 M) was reduced with sodium hydroxide by hydrothermal method, and the pH was maintained at 4.5. The uniform dispersion and stability of CeO2@Se NPs are strongly influenced by the thiol group (–SH) present in MWCNT(SH) supporting matrix. Morphology and microstructure analysis revealed good dispersion of CeO2@Se NPs onto MWCNT(SH) support matrix. The FTIR and UV–Visible spectroscopy results clearly revealed that the CeO2@SeNPs were anchored on MWCNT(SH) matrix. The antimicrobial studies were performed against a set of microbes, and they showed that Gram-negative (G −) stains were relatively more susceptible to CeO2@Se NPs-loaded MWCNT(SH) than Gram-positive (G +) stains. MWCNT(SH)/CeO2@Se NPs exhibited comparatively better microbicidal activity than MWCNT(SH). This is due to the influence of thiol (–SH) groups in stabilizing and protecting CeO2@Se NPs on MWCNT(SH) support against their leaching and agglomeration processes and thus augments the microbicidal effect of MWCNT(SH)/CeO2@Se NPs. [ABSTRACT FROM AUTHOR]

A novel method for selective and sensitive detection of chloride ion plays a vital role in environmental monitoring, industrial and healthcare sectors. Here, we spotlight the synthesis, characterization and electrochemical performance analysis of electrospun PVA-PANi-g-C3N4 nanofibers (NFs) over screen printed carbon electrode and engaged as a modified NF electrode for chloride ion determination. The resulting nanofibers morphological views, functional groups and elemental composition were captured and recorded by FESEM, FTIR and XPS. The electrochemical behaviour of PVA-PANi-g-C3N4 NFs was studied by cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometric techniques, as the results directed that the modified NF electrode reveals a significant electrochemical sensitivity, selectivity for Cl− ion with the value of linear regression co-efficient R2 = 0.99. The lowest limit of detection 0.2 µM with greater sensitivity (1.6082 µM µA/cm2) was succeeded. Owing to its synergistic interaction amid the PVA-PANi with g-C3N4 NF combinations an efficient electron transfer pathway was achieved which leads to an excellent ionic diffusion. Further, the outcomes from the real sample analysis creating them attractive and helping in profound study for electrochemical sensor towards practical applications. [ABSTRACT FROM AUTHOR]

Electrochemically active platinum nanoparticles (Pt NPs) on carbon nanofibers (CNF) with electron-conducting polyaniline (PANi) nanocomposite fabricated by in situ electrodeposition using cyclic voltammetry on glassy carbon electrode (GCE). The bridging between the Pt NPs and CNF with the occurrence of platinum nitride (Pt–N) bonding and π–π bonding demonstrated the stability of PANi. Structural geometry and morphological view authenticates the successful formation of GCE/PANi-CNF-Pt electrocatalyst. To investigate the electrocatalytic performance of the synthesized nanocomposite, cyclic voltammetry, electrochemical impedance spectroscopy and chronoamperometry methods were used in this work. As a result of π–π and electrostatic bonding, the prepared PANi is found to be wrapped with CNF and Pt NPs facilitates in efficient and rapid electron transfer pathway with good stability. Overall, electrochemically active GCE/PANi-CNF-Pt catalyst exhibits excellent electrocatalytic properties and promises potential applications in DMFCs. [ABSTRACT FROM AUTHOR]

Summary: In this study, we report a novel biomass‐derived porous carbon nanostructures (BD‐PCNSs) obtained from Lantana camara stem (LAC) using a simple and low‐cost preparation method. LAC biomass was processed with a temperature‐controlled hydrothermal precarbonization cum pyrolysis technique and followed by alkaline surface activation to achieve BD‐PCNSs. The physicochemical properties for the obtained BD‐PCNSs material were confirmed using X‐ray diffraction, scanning electron microscopy, nitrogen sorption isotherms, and X‐ray photoelectron spectroscopy. As‐prepared BD‐PCNSs exhibited excellent performances toward supercapacitance and wastewater treatment. BD‐PCNSs showed high‐specific capacitance ~146 Fg−1 in the aqueous electrolyte with excellent coulombic efficiency, and cyclic retention affirms its green energy storage device fabrication. Also, maximum adsorption capacity (106.4 mg g−1) was achieved for the efficient removal of ibuprofen from wastewater and proven as a promising eco‐friendly, and low‐cost absorbent material claim its practical applications. [ABSTRACT FROM AUTHOR]

The cobalt selenide nanoparticles (CoSe NPs) were prepared by a simple hydrothermal method, and polyaniline nanofibers (PANI NFs) were prepared by a chemical oxidative polymerization and its composite NFs were prepared by incorporating CoSe onto PANI at the optimized wt% 1:1 by ultrasonication to use as a newer photocathode for dye‐sensitized solar cells (DSSCs). The physio‐chemical properties of the prepared CoSe NPs/PANI NFs composite NFs were investigated by field emission scanning electron microscope, X‐ray diffractometer, and Raman spectroscopy. The results revealed that the phase pure CoSe NPs were decorated onto the PANI NFs without affecting their physio‐chemical nature. The electrochemical characteristics of CoSe NPs/PANI NFs composite NFs as photocathode were investigated by electrochemical AC‐impedance, cyclic voltammetry, and Tafel polarization studies. The CoSe decorated PANI composite NFs displayed excellent electrocatalytic behavior toward the tri‐iodide reduction. Further, DSSC fabricated with CoSe/PANI composite NFs as the photocathode exhibited the highest photoconversion efficiency of 9.14% than that of the pristine CoSe NPs and PANI NFs‐based counter electrodes (CEs). This is attributed to the synergistic electrocatalytic ability of CoSe NPs and the multiple interfacial charge transferability of PANI NFs. These results suggest that CoSe decorated PANI composite NFs could be used as a promising CE to fabricate high‐performance DSSC. [ABSTRACT FROM AUTHOR]

In this work, a metal free polyaniline nanorod (PANI-NR) with graphitic carbon nitride (GCN) nanocomposite has been synthesized by solar irradiation approach an acidic medium without the assistance of any surfactant and template. As synthesized PANI-NR/GCN nanocomposite was characterized by morphology studies, which found that the average diameter of the PANI-NR was 500 to 600 nm and the length of the nanorod range from 3 to 3.5 µm where GCN randomly dispersed on the surface of PANI-NR. The elemental composition, structural and vibrational spectra of PANI-NR/GCN are observed through EDX, Mapping, XRD, and FT-IR studies. Subsequently, the synthesized PANI-NR/GCN nanocomposite was used as an electrocatalyst, which was characterized through cyclic voltammetry, impedance, and chronoamperometric studies. The fabricated PANI-NR/GCN modified electrode shows significant electrocatalytic activity, lower charge resistance, high stability, and longevity towards methanol oxidation reaction (MOR) in an alkaline medium. [ABSTRACT FROM AUTHOR]

Summary: In this study, we report a new phosphotungstic acid‐Titania embedded polyaniline (PANI/PTA/TiO2) nanocomposite modified hybrid electrode for efficient methanol electro‐oxidation reaction. The PANI/PTA/TiO2 nanocomposite was prepared via a simple in‐situ polymerization method. The fabricated modified electrode's surface morphology and elemental analysis were characterized using field‐emission scanning electron microscopy with energy‐dispersive X‐ray spectroscopy and mapping technique. The phase structure and molecular vibrational studies were identified using an X‐ray diffraction and Fourier‐transform infrared spectroscopic techniques. The electrochemical performance of the modified electrodes was studied using cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopic techniques. The PANI/PTA/TiO2 nanohybrid modified electrode displayed the superior electro‐catalytic activity towards methanol oxidation reaction at 0.2 V potential with the charge transfer resistance of 218 Ω, and showed excellent stability up to 1200s in an alkaline medium. The developed nanocomposite material can be used as a potential nanohybrid anode catalyst for the application of direct methanol fuel cells. [ABSTRACT FROM AUTHOR]

Summary: In this study, a simple and facile electrochemical deposition technique was employed to fabricate fluorine‐doped tin oxide‐based polydiphenylamine‐polyaniline/phosphotungstic acid copolymer nanocomposite modified electrode (FTO/PDPA‐PANI/PTA) for high‐performance supercapacitors application. Crystalline and morphological structure and coating thickness of PDPA‐PANI/PTA nanocomposite on FTO were characterized using X‐ray diffraction, scanning electron microscope, and atomic force microscope. The fabricated nanohybrid electrode exhibits superior specific capacitance of 360 Fg−1 at 1 mA current density. The higher capacitive behavior and cyclic steadiness of FTO/PDPA‐PANI/PTA modified electrode were achieved because of the presence of tungsten in the PDPA/PANI co‐polymer nanonetworks provide efficient interaction which enhances the fast electron transfer progressions. Electrochemical impedance spectroscopic (EIS) studies ensure the capacitive behavior of the electrodeposited nanohybrid modified electrode with a characteristic EIS semicircle in the lower frequency region. Further, a superior specific capacitance with 82% excellent capacitance retention after 1000 cycles, recommends a practical application in supercapacitor device electrodes. [ABSTRACT FROM AUTHOR]

The effects of the SnO2 pore size and metal oxide promoters on the sensing properties of SnO2-based thick film gas sensors were investigated to improve the detection of very low H2S concentrations (<1 ppm). SnO2 sensors and SnO2-based thick-film gas sensors promoted with NiO, ZnO, MoO3, CuO or Fe2O3 were prepared, and their sensing properties were examined in a flow system. The SnO2 materials were prepared by calcining SnO2 at 600, 800, 1,000 and 1,200 °C to give materials identified as SnO2(600), SnO2(800), SnO2(1000), and SnO2(1200), respectively. The Sn(12)Mo5Ni3 sensor, which was prepared by physically mixing 5 wt% MoO3 (Mo5), 3 wt% NiO (Ni3) and SnO2(1200) with a large pore size of 312 nm, exhibited a high sensor response of approximately 75% for the detection of 1 ppm H2S at 350 °C with excellent recovery properties. Unlike the SnO2 sensors, its response was maintained during multiple cycles without deactivation. This was attributed to the promoter effect of MoO3. In particular, the Sn(12)Mo5Ni3 sensor developed in this study showed twice the response of the Sn(6)Mo5Ni3 sensor, which was prepared by SnO2(600) with the smaller pore size than SnO2(1200). The excellent sensor response and recovery properties of Sn(12)Mo5Ni3 are believed to be due to the combined promoter effects of MoO3 and NiO and the diffusion effect of H2S as a result of the large pore size of SnO2. [ABSTRACT FROM AUTHOR]

The sensing behavior of SnO2-based thick film gas sensors in a flow system in the presence of a very low concentration (ppb level) of chemical agent simulants such as acetonitrile, dipropylene glycol methyl ether (DPGME), dimethyl methylphosphonate (DMMP), and dichloromethane (DCM) was investigated. Commercial SnO2 [SnO2(C)] and nano-SnO2 prepared by the precipitation method [SnO2(P)] were used to prepare the SnO2 sensor in this study. In the case of DCM and acetonitrile, the SnO2(P) sensor showed higher sensor response as compared with the SnO2(C) sensors. In the case of DMMP and DPGME, however, the SnO2(C) sensor showed higher responses than those of the SnO2(P) sensors. In particular, the response of the SnO2(P) sensor increased as the calcination temperature increased from 400 °C to 800 °C. These results can be explained by the fact that the response of the SnO2-based gas sensor depends on the textural properties of tin oxide and the molecular size of the chemical agent simulant in the detection of the simulant gases (0.1-0.5 ppm). [ABSTRACT FROM AUTHOR]

Co–Fe–Al catalysts prepared using coprecipitation at laboratory scale were investigated and extended to pilot scale for high-calorific synthetic natural gas. The Co–Fe–Al catalysts with different metal loadings were analyzed using BET, XRD, H2-TPR, and FT-IR. An increase in the metal loading of the Co–Fe–Al catalysts showed low spinel phase ratio, leading to an improvement in reducibility. Among the catalysts, 40CFAl catalyst prepared at laboratory scale afforded the highest C2–C4 hydrocarbon time yield, and this catalyst was successfully reproduced at the pilot scale. The pelletized catalyst prepared at pilot scale showed high CO conversion (87.6%), high light hydrocarbon selectivity (CH4 59.3% and C2–C4 18.8%), and low byproduct amounts (C5+: 4.1% and CO2: 17.8%) under optimum conditions (space velocity: 4000 mL/g/h, 350 °C, and 20 bar). [ABSTRACT FROM AUTHOR]