High performance Pt-anchored MoSbased chemiresistive ascorbic acid sensor.

Ascorbic acid (AA), known as vitamin C, is a vital bioactive compound that plays a crucial role in several metabolic processes, including the synthesis of collagen and neurotransmitters, the removal of harmful free radicals, and the uptake of iron by cells in the human intestines. As a result, there is an absolute need for a highly selective, sensitive, and economically viable sensing platform for AA detection. Herein, we demonstrate a Pt-decorated MoSfor efficient detection of an AA biosensor.

Quasicrystal Nanosheet/α-FeO Heterostructure-Based Low Power NO Sensors: Experimental and DFT Studies.

Industrial emissions, environmental monitoring, and medical fields have put forward huge demands for high-performance and low power consumption sensors. Two-dimensional quasicrystal (2D QC) nanosheets of metallic multicomponent AlCoFeNiCu have emerged as a promising material for gas sensors due to their excellent catalytic and electronic properties. Herein, we demonstrate highly sensitive and selective NO sensors developed by low-cost and scalable fabrication techniques using 2D QC nanosheets and α-FeO nanoparticles.

Photocatalytic degradation of methylene blue at nanostructured ZnO thin films.

The photocatalytic degradation of the wastewater dye pollutant methylene blue (MB) at ZnO nanostructured porous thin films, deposited by direct current reactive magnetron sputtering on Si substrates, was studied. It was observed that over 4 photocatalytic cycles (0.3 mg · lMB solution, 540 minUV irradiation), the rate constantof MB degradation decreased by ∼50%, varying in the range (1.

Flower-like ZnO Nanostructures Local Surface Morphology and Chemistry.

This work presents the results of comparative studies using complementary methods, such as scanning electron microscopy (SEM), X-ray photoemission spectroscopy (XPS), and thermal desorption spectroscopy (TDS) to investigate the local surface morphology and chemistry of flower-like ZnO nanostructures synthesized by the thermal oxidation technique on native Si/SiO substrates. SEM studies showed that our flower-like ZnO nanostructures contained mostly isolated and irregular morphological low-dimensional forms, seen as rolled-up floss flowers, together with local, elongated, complex stalks similar to Liatris flowers, which contained joined short flosses in the form of nanodendrites. Beyond this, XPS studies showed that these nanostructures exhibited a slight surface nonstoichiometry, mostly related to the existence of oxygen-deficient regions, combined with strong undesired C surface contamination.

Covalent Immobilization of Organic Photosensitizers on the Glass Surface: Toward the Formation of the Light-Activated Antimicrobial Nanocoating.

Two highly efficient commercial organic photosensitizers-azure A (AA) and 5-(4-aminophenyl)-10,15,20-(triphenyl)porphyrin (APTPP)-were covalently attached to the glass surface to form a photoactive monolayer. The proposed straightforward strategy consists of three steps, i.e.

Correlation between Microstructure and Chemical Composition of Zinc Oxide Gas Sensor Layers and Their Gas-Sensitive Properties in Chlorine Atmosphere.

In this article, we present results concerning the impact of structural and chemical properties of zinc oxide in various morphological forms and its gas-sensitive properties, tested in an atmosphere containing a very aggressive gas such as chlorine. The aim of this research was to understand the mechanism of chlorine detection using a resistive gas sensor with an active layer made of zinc oxide with a different structure and morphology. Two types of ZnO sensor layers obtained by two different technological methods were used in sensor construction.

Novel insight on the local surface properties of ZnO nanowires.

Novel insight on the local surface properties of ZnO nanowires (NW) deposited by the evaporation-condensation method on Ag-covered Si substrates is proposed, based on the results of comparative studies by using the scanning electron microscopy (SEM), x-ray photoemission spectroscopy (XPS) and thermal desorption spectroscopy (TDS) methods, respectively. SEM studies showed that ZnO nanowires (nanoribbons) are mostly isolated and irregular, having the average length μm and the average at the level of tens nm, respectively. Our XPS studies confirmed their evident surface non-stoichiometry, combined with strong C surface contaminations, which was related to the existence of oxygen-deficient regions.

Rheotaxially Grown and Vacuum Oxidized SnO Nanolayers for NO Sensing Characteristics at Ppb Level and Room Temperature.

Correspondence: Barbara [...

Studies of NO Gas-Sensing Characteristics of a Novel Room-Temperature Surface-Photovoltage Gas Sensor Device.

In this work the characteristics of a novel type of room temperature NO gas sensor device based on the surface photovoltage effect are described. It was shown that for our SPV gas sensor device, using porous sputtered ZnO nanostructured thin films as the active gas sensing electrode material, the basic gas sensor characteristics in a toxic NO gas atmosphere are strongly dependent on the target NO gas flow rate. Moreover, it was also confirmed that our SPV gas sensor device is able to detect the lowest NO relative concentration at the level of 125 ppb, with respect to the commonly assumed signal-to-noise (S/N) ratio, as for the commercial devices.

Surface Properties of SnO₂ Nanowires Deposited on Si Substrate Covered by Au Catalyst Studies by XPS, TDS and SEM.

The surface chemistry and the morphology of SnO₂ nanowires of average length and diameter of several µm and around 100 nm, respectively, deposited by vapor phase deposition (VPD) method on Au-covered Si substrate, were studied before and after subsequent air exposure. For this purpose, surface-sensitive methods, including X-ray photoelectron spectroscopy (XPS), thermal desorption spectroscopy (TDS) and the scanning electron microscopy (SEM), were applied. The studies presented within this paper allowed to determine their surface non-stoichiometry combined with the presence of carbon contaminations, in a good correlation with their surface morphology.

A Novel Type Room Temperature Surface Photovoltage Gas Sensor Device.

In this paper a novel type of a highly sensitive gas sensor device based on the surface photovoltage effect is described. It is based on the Kelvin probe approach. Porous ZnO nanostructured thin films deposited by the direct current (DC) reactive magnetron sputtering method are used as the active gas sensing electrode material.

Oxide-organic heterostructures: a case study of charge transfer disturbance at a SnO-copper phthalocyanine buried interface.

Reduced tin dioxide/copper phthalocyanine (SnOx/CuPc) heterojunctions recently gained much attention in hybrid electronics due to their defect structure, allowing tuning of the electronic properties at the interface towards particular needs. In this work, we focus on the creation and analysis of the interface between the oxide and organic layer. The inorganic/organic heterojunction was created by depositing CuPc on SnOx layers prepared with the rheotaxial growth and vacuum oxidation (RGVO) method.

Surface Properties of Nanostructured, Porous ZnO Thin Films Prepared by Direct Current Reactive Magnetron Sputtering.

In this paper, the results of detailed X-ray photoelectron spectroscopy (XPS) studies combined with atomic force microscopy (AFM) investigation concerning the local surface chemistry and morphology of nanostructured ZnO thin films are presented. They have been deposited by direct current (DC) reactive magnetron sputtering under variable absolute Ar/O₂ flows (in sccm): 3:0.3; 8:0.

Pure and Highly Nb-Doped Titanium Dioxide Nanotubular Arrays: Characterization of Local Surface Properties.

This paper presents the results of studies of the local surface properties of pure and highly Nb-doped (12 wt %) TiO₂ nanotubes (TNT) using the X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) methods, respectively. XPS analysis showed that the pure TNT exhibit an evident over-stoichiometry combined with high level of undesired C contaminations, which was confirmed by the relative concentration of specific elements O, Ti and C (with respect to all the surface atoms) equal to 0.46, 018 and 0.

Impact of air exposure and annealing on the chemical and electronic properties of the surface of SnO nanolayers deposited by rheotaxial growth and vacuum oxidation.

In this paper the SnO nanolayers were deposited by rheotaxial growth and vacuum oxidation (RGVO) and analyzed for the susceptibility to ambient-air exposure and the subsequent recovery under vacuum conditions. Particularly the surface chemistry of the layers, stoichiometry and level of carbon contamination, was scrutinized by X-ray photoelectron spectroscopy (XPS). The layers were tested i) pristine, ii) after air exposure and iii) after UHV annealing to validate perspective recovery procedures of the sensing layers.

XPS, TDS, and AFM studies of surface chemistry and morphology of Ag-covered L-CVD SnO2 nanolayers.

This is well known that the selectivity and sensitivity of tin dioxide (SnO2) thin film sensors for the detection of low concentration of volatile sulfides such as H2S in air can be improved by small amount of Ag additives. In this paper we present the results of comparative X-ray photoelectron spectroscopy (XPS), thermal desorption spectroscopy (TDS), and atomic force microscopy (AFM) studies of the surface chemistry and morphology of SnO2 nanolayers obtained by laser-enhanced chemical vapor deposition (L-CVD) additionally covered with 1 monolayer (ML) of Ag. For as deposited SnO2 nanolayers, a mixture of tin oxide (SnO) and tin dioxide (SnO2) with the [C]/[Sn] ratio of approximately 1.

Surface chemistry of SnO2 nanowires on Ag-catalyst-covered Si substrate studied using XPS and TDS methods.

In this paper we investigate the surface chemistry, including surface contaminations, of SnO2 nanowires deposited on Ag-covered Si substrate by vapor phase deposition (VPD), thanks to x-ray photoelectron spectroscopy (XPS) in combination with thermal desorption spectroscopy (TDS). Air-exposed SnO2 nanowires are slightly non-stoichiometric, and a huge amount of C contaminations is observed at their surface. After the thermal physical desorption (TPD) process, SnO2 nanowires become almost stoichiometric without any surface C contaminations.