To achieve good living standards, it is critical to make high-performance toxic gas sensing devices for public safety, environmental pollutant control, industrial operations, and other applications. ...For this purpose, we demonstrate CuO anchored SnO2 nanostructures for H2S gas sensors. The selectivity was improved by anchoring with CuO for a total 60 s duration at four equal consecutive cycles to achieve good selectivity towards H2S molecules. The pristine CuO shows instability and metallic behaviour when it is exposed to H2S for a longer time. Furthermore, the proposed gas sensor shows good selectivity toward H2S as compared to other gases H2, NO2, CO2, and NH3. The sensing response was measured at around 69 % at the optimal operating temperature of 150°C. It is observed that CuS formation has better selectivity as compared to pristine SnO2 and a slight improvement in sensitivity is observed. As a result, a promising strategy for designing and producing good-performance H2S gas sensors would be to CuO anchor on SnO2 nanostructures. The proposed sensors may be integrated with IoT platforms and used for the detection of H2S in the sewer line and leak detection in the petroleum industry.
Display omitted
•SnO2 thin film was anchored with CuO at different time duration using RF sputtering for H2S gas sensing.•The sensor exhibits higher sensing response of 69 % at 150 ºC for 100 ppm of H2S with a LoD of 1 ppm.•Comparative analysis was performed for H2S gas detection for both SnO2 and CuO/SnO2 based sensors.•Excellent selectivity and slight improved sensitivity was observed with CuO/SnO2 based gas sensor.
This review offers insights into the fundamental properties of bismuth oxychalcogenides Bi
2
O
2
X (X = S, Se, Te) (BOXs), concentrating on recent advancements primarily from studies published over ...the past five years. It examines the physical characteristics of these materials, synthesis methods, and their potential as critical components for gas sensing, biosensing, and optical sensing applications. Moreover, it underscores the implications of these advancements for the development of military, environmental, and health monitoring devices.
This minireview explores the unique properties and potential applications of bismuth oxychalcogenide nanosheets in chemical and biological sensing, and photodetection.
Novel metal functionalization of the semiconductor metal oxide surface is an effective approach to address the poor selectivity with increased sensing performance. Functionalization enhances ...sensitivity through chemical and electronic sensitization, while metal nanoparticles catalyze target gas molecule adsorption. Taking this approach into consideration, we demonstrated Silver (Ag) nanoparticles functionalized α-Fe2O3 nanostructured thin film gas sensor for sensing of NO2 molecules. The RF-sputtered α-Fe2O3 nanostructured thin film were deposited at 600 °C followed by materials characterizations. Furthermore, we functionalized the α-Fe2O3 sensor with various quantity of Ag NPs using sputtering techniques and observed the effect on sensing performance. The α-Fe2O3 sensor with 10 s Ag functionalization shows the highest relative response among all samples of ∼71.02% for 100 ppm NO2 concentration at 150 °C. Further, the selectivity was dramatically improved upon the functionalization with Ag due to its catalytic properties in comparison with the pristine sensor. The Ag functionalization results in an improved surface-to-volume ratio and more reaction and adsorption sites for gas molecules. As a result, Ag functionalization seems to be a potential strategy to increase the sensing response of an α-Fe2O3 sensor for selective sensing of NO2.
Display omitted
•Fabrication of Ag anchored α-Fe2O3 nanostructures for NO2 gas sensors.•Further α-Fe2O3 thin film was anchored with Ag for 5, 10 and 15 s using DC sputtering.•Ag NPs increase surface-to-volume ratio and adsorption sites for gas molecules.•The measured sensing response was 71.02% at 150 °C for 100 ppm of NO2 around with a lower detection limit of 1 ppm.•In Ag/α-Fe2O3 better selectivity as compared to pristine α-Fe2O3 and drastic improvement in sensitivity is observed.
•Bi2O2S nanosheets prove to be a highly efficient visible-light photocatalyst.•Bi2O2S nanosheets demonstrate remarkable photocatalytic degradation of organic dye.•Bi2O2S nanosheets hold great ...potential for remedying water sources and effluents.
Herein, we introduce the first investigation into the photocatalytic properties of ultrathin Bi2O2S nanosheets prepared by a hydrothermal method. These nanosheets demonstrate exceptional efficiency in degrading congo red (CR) and rose bengal (RB) when exposed to visible light. The degradation rates reached approximately 82 % for CR and 80 % for RB, respectively. The rate constants for CR and RB degradation were found to be 1.8 × 10-2 min−1 and 1.3 × 10-2 min−1, respectively, during a 75 and 150-minute exposure to Bi2O2S nanosheets.
This study reports, for the first time, the utilization of two-dimensional (2D) tellurium (Te) nanosheets for the efficient nonenzymatic detection of hydrogen peroxide (H2O2). H2O2 acts as a pivotal ...biomarker with widespread applications across environmental, biological, industrial, and food processing domains. However, an excessive accumulation of H2O2 in the body poses a severe threat to human life. Consequently, the imperative need for a selective, sensitive, and cost-effective sensing platform for H2O2 detection has gained paramount significance. Employing a low-cost and straightforward hydrothermal method, Te nanosheets were synthesized to address the escalating demand for a reliable detection platform. The as-synthesized Te nanosheets are characterized through Raman spectroscopy and atomic force microscopy techniques. The electrochemical performance of the Te nanosheets integrated onto a glassy carbon (Te-GC) electrode was thoroughly investigated using cyclic voltammetry, differential pulse voltammetry, and chronoamperometry. The experiments were designed to evaluate the response of the Te-GC electrode in the presence and absence of H2O2, alongside its performance in the detection of other pertinent interfering analytes. The sensor shows a limit of detection of 0.47 µM and a sensitivity of 27.2 µA µM−1 cm−2 towards H2O2. The outcomes of this study demonstrate the efficacy of Te nanosheets as a promising material for nonenzymatic H2O2 detection in urine samples. The simplicity and cost-effectiveness of the hydrothermal synthesis process, coupled with the notable electrochemical performance of the Te/GC electrode, highlight the potential of Te nanosheets in the development of a robust sensing platform. This research contributes to the ongoing efforts to enhance our capabilities in monitoring and detecting H2O2, fostering advancements in environmental, biomedical, and industrial applications.
Over the past few decades, the metal oxide-based thin-film sensors have been widely studied and commercialized for gas sensing applications but their poor sensing response and high temperature ...operation (>300°C) are the issues to be addressed. Here, we demonstrate the MoS 2 decorated α-Fe 2 O 3 thin film-based NO 2 gas sensor. The α-Fe 2 O 3 thin film was deposited on silicon substrate using RF magnetron sputtering technique at 6000C substrate temperature. The α-Fe 2 O 3 thin films were characterized using an X-ray diffractometer and a Scanning Electron microscope for structural and morphological characterizations. Further, we decorated the Fe 2 O 3 thin film using hydrothermally synthesized MoS 2 nanoparticles dispersed in ethanol via the drop-casting method to increase the response towards NO 2 gas. The MoS 2 decorated sensor shows a fast gas detection with the improved response of (ΔR/R a %) of ~69% at 150°C for 100ppm of NO 2 gas, which is 68% higher as compared to the pristine sample (~42%). The sensor shows a fast response time of ~34 sec and a moderate recovery time of ~95 sec. The decoration of MoS 2 nanoparticles has increased the surface to volume ratio and active sites and hence increased the number of gas molecules that can react with the surface of the sample. The sensor shows high sensitivity and selectivity towards NO 2 due to increased holes and reduced barrier height in MoS 2 /α-Fe 2 O 3 p-p heterojunctions.
A resistance random access memory (RRAM), based on a metal oxide thin film with resistive switching behavior, has been explored as an emerging candidate for their application as nonvolatile memories, ...due to their various advantages, such as simple device configuration, long data retention, high switching speed, and low operating voltage. Various metal oxides have been explored for resistive switching applications including, e.g., binary and ternary compounds. Among all metal oxides, the perovskites have attracted considerable interest due to their potential to be used for information storage and neuromorphic application. In this work, we demonstrate stable bipolar resistive switching devices based on the sputtered LaFeO<inline-formula> <tex-math notation="LaTeX">_{\text{3}}</tex-math> </inline-formula> thin film on fluorine doped tin oxide (FTO)-coated glass with circular-shaped silver contacts. The memory performance of fabricated devices was characterized as a function of the thickness of the LFO thin layer. The resistive switching properties are investigated using macroscopic <inline-formula> <tex-math notation="LaTeX">\textit{I}</tex-math> </inline-formula>-<inline-formula> <tex-math notation="LaTeX">\textit{V}</tex-math> </inline-formula> measurements, showing low-voltage switching with a high ON-OFF ratio (<inline-formula> <tex-math notation="LaTeX">\approx </tex-math> </inline-formula>300) and long retention (<inline-formula> <tex-math notation="LaTeX">\ge </tex-math> </inline-formula>9000 s). The fabricated devices demonstrate the stable, low voltage and high-speed switching. Furthermore, in this work, we demonstrate the synaptic behavior of the LFO thin-film memory devices, as it exhibits analog memory characteristics, potentiation, and depression.
The effect of deposition temperature on surface morphology and write once read many times resistive switching properties of RF sputtered BaTiO
3
(BTO) thin films has been demonstrated. A conventional ...sandwiched structure was used to fabricate the memory cell with FTO as bottom electrode and silver as top electrode. The devices exhibit switching from a high resistance state to a low resistance state with the conductive filament(s) formation through BTO active layer. The switching performances are investigated for different devices with different deposition temperatures, varying from room temperature (RT) to 450 °C. All the devices are characterized for a voltage sweep of − 1.5 V to 1.5 V with 12,000 pulses for retention and 300 write-read erase read cycles. Shifting in the switching voltage to a lower value from 1.31 to 0.49 V (450 °C) is recorded with the increased deposition temperature. We observe the highest on-off ratio of 5.9 × 10
6
for sample deposited at room temperature and 0.9 × 10
4
for sample deposited at 450 °C. The write read erase read characterizations for over 1000 cycles were carried out for all four devices to test the device reliability and observe the stable read current over the period irrespective of erase cycles. The fabricated devices show stable and reliable reading endurance and data retention characteristics for more than 12,000 s.
This study reports, for the first time, the utilization of two-dimensional (2D) tellurium (Te) nanosheets for the efficient nonenzymatic detection of hydrogen peroxide (Hsub.2 Osub.2 ). Hsub.2 Osub.2 ...acts as a pivotal biomarker with widespread applications across environmental, biological, industrial, and food processing domains. However, an excessive accumulation of Hsub.2 Osub.2 in the body poses a severe threat to human life. Consequently, the imperative need for a selective, sensitive, and cost-effective sensing platform for Hsub.2 Osub.2 detection has gained paramount significance. Employing a low-cost and straightforward hydrothermal method, Te nanosheets were synthesized to address the escalating demand for a reliable detection platform. The as-synthesized Te nanosheets are characterized through Raman spectroscopy and atomic force microscopy techniques. The electrochemical performance of the Te nanosheets integrated onto a glassy carbon (Te-GC) electrode was thoroughly investigated using cyclic voltammetry, differential pulse voltammetry, and chronoamperometry. The experiments were designed to evaluate the response of the Te-GC electrode in the presence and absence of Hsub.2 Osub.2 , alongside its performance in the detection of other pertinent interfering analytes. The sensor shows a limit of detection of 0.47 µM and a sensitivity of 27.2 µA µMsup.−1 cmsup.−2 towards Hsub.2 Osub.2 . The outcomes of this study demonstrate the efficacy of Te nanosheets as a promising material for nonenzymatic Hsub.2 Osub.2 detection in urine samples. The simplicity and cost-effectiveness of the hydrothermal synthesis process, coupled with the notable electrochemical performance of the Te/GC electrode, highlight the potential of Te nanosheets in the development of a robust sensing platform. This research contributes to the ongoing efforts to enhance our capabilities in monitoring and detecting Hsub.2 Osub.2 , fostering advancements in environmental, biomedical, and industrial applications.
Reducing the operating voltage and processing temperature are the crucial factors in the progression of organic field-effect transistors (OFETs) in flexible portable applications. Here, we have ...demonstrated RF sputtering deposited Ba0.5Sr0.5TiO3(BST) as high-k dielectric material for high performance operationally stable flexible low voltage operated OFETs. It was found that the BST deposition parameters can enormously affect the film properties like dielectric constant, surface morphology, and the crystallinity. The room-temperature-deposited BST films were found to be amorphous in nature with low leakage current, high dielectric constant, smoother surface morphology and high electromechanical stability. The fabricated flexible OFETs with optimized BST film have shown excellent electrical performance with max. field-effect mobility (μmax) of 1.01 cm2 V–1s–1 with near zero threshold voltage (V TH) and I on/I off of ∼105 while operating at −5 V. The fabricated devices were found to be operationally and electromechanically stable when subjected to various electrical and mechanical stress. The investigation has demonstrated that the proposed room-temperature-deposited BST is a suitable candidate for gate dielectric in low voltage operated, long-term electromechanical stable flexible OFETs.
