- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
In situ photoelectrochemical activation of sulfite by MoS2 photoanode for enhanced removal of ammonium nitrogen from wastewater
摘要： The advanced oxidation processes (AOPs) based on oxysulfur radicals (SO3??, SO4?? and SO5??) has been receiving growing attention in wastewater treatment. In this study, we report the in situ photoelectrochemical activation of sulfite to produce oxysulfur radicals with MoS2 nanosheets as a wide spectrum absorptive photoanode. At alkaline condition, the selective and efficient conversion of ammonia to dinitrogen was exclusively achieved in the presence of sulfite electrolyte under visible light irradiation. The sulfite plays multiple roles such as working as hole scavenger for improving stability of MoS2 electrode by inhibiting photo-corrosion and serving as precursor of oxysulfur radicals in the meantime. The influences of radical scavenger, dissolved oxygen and electrolyte on the photoelectrochemical, electrochemical and photochemical conversion of ammonia verified that oxysulfur radicals are more powerful than hydroxyl radicals in terms of ammonia conversion. The proposed system appears to be applicable to in situ treatment of wastewater containing of ammonia and sulfite pollutants, such as wastewater from ammonia-absorption-desulfurization of combustion smoke. This work also provides a new protocol in the design of new AOPs, where oxysulfur radicals can work together with hydroxyl radicals for simultaneous pollutants degradation and detoxification.
关键词： photoelectrocatalysis,sulfite activation,MoS2,advanced oxidation process,ammonia oxidation
更新于2025-09-10 09:29:36
-
Ammonia in Jupiter’s Atmosphere: Spatial and Temporal Variations of the NH3 Absorption Bands at 645 and 787 Nm
摘要： Based on the material of long-term spectrophotometric observations of Jupiter, we studied the weak absorption bands of ammonia at 645 and 878 nm, whose behavior had previously been little studied. A clearly expressed depression of ammonia absorption in the 787-nm band was found in the Northern Equatorial Belt (NEB) of Jupiter. In the Great Red Spot, this band also exhibits substantial weakening. The position of the depression in the NEB is similar to that of the enhanced brightness temperature detected in the observations of the millimeter-wave radio emission, which is considered to be a result of the reduced ammonia content in this belt. At the same time, the weakening of the 787-nm band in the Red Spot is most likely caused by the enhanced bulk density of clouds, which influences the formation of absorption bands in the multiple scattering by cloud particles. The brightness temperature in the Red Spot is relatively low, as seen from observations in the radio and thermal IR ranges. We studied the spatial and temporal variations of the 645- and 787-nm bands in five belts of Jupiter: the Equatorial Zone (EZ), both Equatorial Belts (SEB and NEB), and both Tropical Zones (STZ and NTZ). The observations covered the time interval from 2005 to 2015, i.e., almost a complete orbital period of Jupiter. These observations confirmed the systematic character of the depression of the 787-nm band in the NEB and the difference in the latitudinal variations of the 645- and 787-nm bands. The latter can be related to features of the vertical distribution of the cloud density, which has a different influence on bands of different intensity.
关键词： spectrophotometry,molecular absorption,atmosphere,thermal radiation,clouds,ammonia,Great Red Spot,Jupiter
更新于2025-09-10 09:29:36
-
Facile Method to Synthesize N-Graphene Nano Sheets
摘要： In this paper, we reported about the facile method to generate N-Graphene Nano Sheets (N-GNS) on room temperature. The purposes of this research are to synthesize and characterize N-GNS. This research used the modified Hummers’s method to generate GNS and doping nitrogen to N-GNS used ammonia 10 M at T = 30oC. The N-GNS was characterized by using XRD, FTIR and SEM-EDX. The XRD data show that N atoms was well be deposited on GNS to form N-GNS, it was indicated by the broad and weak peak was appear at 2θ = 26.3o. This data is consistent with SEM-EDX, where the N atoms content on N-GNS is 2.72 %. FTIR data also defenitely confirm that there is interaction between C and N, indicating by the peak is appear at 1396 cm-1. All of data show that the N is exist on GNS, it probes N-GNS may synthesized by facile method on room temperature.
关键词： N-Graphene Nano Sheets,Graphene Nano Sheets,Room Temperature,Ammonia
更新于2025-09-10 09:29:36
-
Design and analysis of electrostatic-charge plasma based dopingless IGZO vertical nanowire FET for ammonia gas sensing
摘要： In this paper, Dopingless Gate All Around (GAA) Vertical Nanowire Field Effect Transistor (VNWFET) is designed with artificial material Indium Gallium Zinc Oxide (IGZO) as a channel material. IGZO channel has high electron mobility compared to more traditional amorphous semiconductors. In VNWFETs, since the channel length (Lch) is characterized vertically, it can be relaxed without area penalty on-chip, which in turn also allows some relaxation in the nanowire diameter while keeping optimum short-channel-effects control. Electrostatic-Charge Plasma technique is used to form a source-drain region on an intrinsic body of IGZO material. At the source side, the N+ region is formed by selecting the appropriate work function of the metal electrode, and at the drain side, the N+ region is formed by giving biasing to the metal electrode. N+ channel dopingless VNWFET with the catalytic metal gate is proposed for ammonia gas sensing. Cobalt, Molybdenum, and Ruthenium are used as a gate electrode in ammonia gas detection due to their high reactivity towards ammonia. Also, we have compared their ON and OFF sensitivity of the proposed device toward the gas adsorption. Due to the presence of gas on the gate, the metal work function of gate metal changes which varies the OFF-current (IOFF), ON-current (ION) and Threshold voltage (Vth) as these are considered as sensitivity parameters for sensing the ammonia gas molecules. The dimensional parameters (radius, and length) and dielectric materials are varied to check the change in device sensitivities. Results show that as the work function varies increases 50, 100, 150, 200meV and 250meV for catalytic metal at the gate, the sensitivity is increased.
关键词： Vertical nanowire FET (VNWFET),Indium Gallium Zinc Oxide (IGZO),Electrostatic-Charge Plasma (E-CP),Ammonia Gas sensor
更新于2025-09-10 09:29:36
-
Induction of postharvest resistance in melon using pulsed light as abiotic stressor
摘要： The aim of this study was use the pulsed light (PL) as tool to booster the postharvest resistance in melons. Cantaloupe melons at mature stage were submitted to the treatments as follows: control, pulsed light (PL; 9 J cm?2), 1-methylcyclopropene (1-MCP; 600 nL L-1) and 1-MCP + PL (600 nL L-1 + 9 J cm?2). Postharvest resistance measurements according survival analysis developed at 4 °C, included: ethylene production, 1-aminocyclopropane-L-carboxylic acid (ACC) oxidase activity, ACC synthase activity, firmness, pH, soluble solids, titratable acidity, SS/AT ratio, soluble sugars, vitamin C, total polyphenols, phenylalanine ammonia lyase (PAL) activity, colour epicarp, free polyamines (putrescine-Put, spermine-Spe and spermidine-Spd) and total polyamines (TPo). Combined effect of the PL+1-MCP promoted an additional of 12 days in the shelf life of melons. PL limited the ethylene biosynthesis leading to an immediate upregulation of polyamines (Put + Spe + Spd), hence, associated with high amounts of TPo (56%). PL treatment promoted an increase of PAL activity (67%) that synthesized high content of phenolic compounds (55%). The results suggest that PL with a fluence of 9 J cm?2 stimulate the postharvest defense mechanisms in melon, due to the ethylene production limitation, which was influenced by the increased polyamines, maintaining the quality attributes.
关键词： Ethylene,Putrescine,Abiotic stress,Polyamines,Phenylalanine ammonia lyase
更新于2025-09-10 09:29:36
-
Implementing a method based on near infrared spectroscopy for the “in-situ” determination of ammonia/water composition in an absorber test bench
摘要： This study presents the first results of composition measurement in an ammonia/water mixture determined at real time using near-infrared (NIR) spectroscopy in an absorber test bench. Two cells were designed and constructed; a static cell for calibrating and a dynamic cell for measuring in the absorber test bench. The ammonia absorption band was not significantly affected by the solution flow rate and neither by small variations in the temperature and pressure. A linear regression model between the absorbance value at 1033 nm and the ammonia concentration was established. This model was used to estimate the concentration in an ammonia/water absorber test bench. The methodology was validated by density measurements of the samples. The value of the mean deviation was 0.0024.
关键词： ammonia/water composition,near-infrared spectroscopy,absorber test bench,real-time measurement
更新于2025-09-10 09:29:36
-
Improving gas sensing by CdTe decoration of individual aerographite microtubes
摘要： Novel gas sensors have been realized by decorating clusters of tubular Aerographite with CdTe using magnetron sputtering techniques. Subsequently, individual microtubes were separated and electrically contacted on a SiO2/Si substrate with pre-patterned electrodes. Cathodoluminescence, electron microscopy and electrical characterization prove the successful formation of a polycrystalline CdTe thin film on Aerographite enabling an excellent gas response to ammonia. Furthermore, the dynamical response to ammonia exposure has been investigated, highlighting the quick response and recovery times of the sensor, which is highly beneficial for extremely short on/off cycles. Therefore, this gas sensor reveals a large potential for cheap, highly selective, reliable and low-power gas sensors, which are especially important for hazardous gases such as ammonia.
关键词： ammonia,electron microscopy,nanocomposite,hybrid material,gas sensing
更新于2025-09-09 09:28:46
-
Ammonia Sensing Characteristics of a Tungsten Trioxide Thin-Film-Based Sensor
摘要： A tungsten trioxide (WO3) thin-film-based ammonia sensor device prepared using radio frequency sputtering is reported and studied. A very thin WO3 film (~10 nm) is employed in the studied device. Experimentally, the studied device exhibits a high ammonia sensing response of 13.7 (at 1000-ppm NH3/air, 250 °C), an extremely low detection level (≤10-ppb NH3/air, 250 °C), a relatively low optimal operating temperature of 250 °C, and a widespread sensing concentration range. Furthermore, the device shows advantages including a simple structure, easy fabrication, and relatively lower operating temperature (≤250 °C). Thus, the proposed WO3 thin-film-based sensor device is promising for high-performance ammonia sensing applications.
关键词： Ammonia,detection level,semiconducting metal oxide (SMO),sensing response,tungsten trioxide (WO3),sputtering
更新于2025-09-09 09:28:46
-
Defected graphene as ammonia sensor: Theoretical Insight
摘要： Defects are often symbolised as deformity in material that deteriorate its performance. However in nanoscale regime, defects lead to generate a useful and novel material for device applications. In the present report, the vacancy defects i.e. single vacancy and double vacancy defects (with different symmetry) on graphene sheet have been analysed to understand the electronic as well as transport properties using density functional theory and NEGF approach. Conductance, current-voltage and sensitivity analysis, these defected graphene sheet have been examined for gas sensing application particularly for ammonia gas. The study observes that a single vacancy defected graphene is a good candidate for ammonia molecule sensing, in comparison to double vacancy.
关键词： DFT,Sensitivity,Ammonia,Graphene,Defects,Conductance
更新于2025-09-09 09:28:46
-
Polymer Foam-Supported Chemically Reduced Graphene Oxide Conductive Networks for Gas Sensing
摘要： In this work, gas sensors based on chemically reduced graphene oxide (rGO) foams were reported for NH3 detection. Polymer foams were used as scaffolds to support rGO, and the resultant soft sensing devices exhibited a high sensitivity, high selectivity, and rapid recovery for NH3 detection at room temperature. The sensor showed more than 0.90% and 3.67% resistance changes respectively, when it’s exposed to 1 ppm and 50 ppm NH3. The graphene foam gas sensors (FGS) also showed excellent repeatability. Furthermore, the response of rGO foam gas sensor to NH3 was more than two times higher than that to methanol vapors diluted to 1% of the saturated vapor concentration. Above all, the unique features, such as simple preparation, low cost and energy consumption, as well as excellent sensing performance, endow the sensor a great potential for NH3 detection.
关键词： Ammonia,Three-Dimensional,Graphene,Gas Sensor,Foam
更新于2025-09-09 09:28:46