Cl2 Gas Research Articles

Exploring penta-ZnS2 monolayer as potential gas sensor for toxic gases based on first principles

To gain a deeper understanding of the application of ZnS2 monolayer in gas sensors, this paper predicts the electronic properties and gas sensing performance of CO, CH4, Cl2, H2S, NO and NH3 gas molecules adsorbed on ZnS2 monolayer based on first principles research. The results show that ZnS2 is sensitive to CO, Cl2, H2S, NO and NH3 by chemisorption and to CH4 by strong physisorption. The adsorption of gases effectively changes the electronic properties and gas sensing properties on ZnS2, and the bandgap of the adsorbed system changes significantly compared with the intrinsic ZnS2, and the characteristics of the work function can effectively distinguish various gases. Our calculations are of great significance for exploring the sensing applications of ZnS2 monolayer as a new member of the gas sensor family, and we expect that this work will provide new perspectives and theoretical foundations for the possible applications of ZnS2 monolayer in the sensing and processing of CO, CH4, Cl2, H2S, NO and NH3 gases.

Real-time analysis of anodic mixed gas generated on carbon electrodes during TiO reduction in a LiCl-based salt at 650 °C

The anode gas components produced during the electrolytic reduction of TiO was analyzed in this study in real time using a carbon anode in LiCl containing various Li2O and Li2CO3 concentrations under high-potential operation at 650 °C. A molten salt with 0.3 wt.% Li2O under 6 V cell voltage predominantly generated CO2 until depletion of the initial oxygen ion source, after which Cl2 gas began to form. A molten salt containing 0.2 and 1.3 wt.% Li2O and 1.3 wt.% Li2CO3, respectively, also generated CO2 as the main anode gas, followed by CO, O2, and Cl2 gas generation. In contrast, a molten salt with 0.8 and 0.5 wt.% Li2O and Li2CO3, respectively, initially generated CO, leading to carbonate accumulation, which gradually decreased as the concentration of generated CO2 increased and it became the dominant gas, while that of O2 remained constant (6–9%). Cl2 was predominantly generated upon depletion of the oxygen ion source in the salt. Cl2 reacted with carbonate ions in the salt, thus releasing CO2 gas and preventing carbonate accumulation in the salt. This study revealed that anode gas composition during electrolytic reduction with carbon anodes is critically influenced by the oxygen ion source concentration of the salt.

Direct electrosynthesis and separation of ammonia and chlorine from waste streams via a stacked membrane-free electrolyzer

Electrosynthesis, a viable path to decarbonize the chemical industry, has been harnessed to generate valuable chemicals under ambient conditions. Here, we present a membrane-free flow electrolyzer for paired electrocatalytic upcycling of nitrate (NO3−) and chloride (Cl−) to ammonia (NH3) and chlorine (Cl2) gases by utilizing waste streams as substitutes for traditional electrolytes. The electrolyzer concurrently couples electrosynthesis and gaseous-product separation, which minimizes the undesired redox reaction between NH3 and Cl2 and thus prevents products loss. Using a three-stacked-modules electrolyzer system, we efficiently processed a reverse osmosis retentate waste stream. This yielded high concentrations of (NH4)2SO4 (83.8 mM) and NaClO (243.4 mM) at an electrical cost of 7.1 kWh per kilogram of solid products, while residual NH3/NH4+ (0.3 mM), NO2− (0.2 mM), and Cl2/HClO/ClO− (0.1 mM) pollutants in the waste stream could meet the wastewater discharge regulations for nitrogen- and chlorine-species. This study underscores the value of pairing appropriate half-reactions, utilizing waste streams to replace traditional electrolytes, and merging product synthesis with separation to refine electrosynthesis platforms.

Comparison of Gas-sensitive response of three metal-doped GaNNT with Pb, Pd and Pt after adsorption of hazardous gases

In this paper, we comparatively analyze the gas-sensing ability of Pb, Pd and Pt metal-doped GaNNT (M-GaNNT) materials for the hazardous H2S, SO2, NH3 and Cl2 gases. The adsorption structure, adsorption energy (Eads), density of states (DOS), differential charge density and frontier molecular orbital of the M-GaNNT adsorbed hazardous gas have been studied based on the density functional theory (DFT) calculations. The results show that the energy gap of Pb-GaNNT performs the largest change with an increasing percentage change of 358 % after the Cl2 adsorption compared with that before the Cl2 adsorption, while the energy gap of Pt-GaNNT has the least change with an average value of 20.8 %. The doping of metal atoms can effectively improve the gas-sensitivity of M-GaNNT, and the gas-sensitivity follows the order of Pb-GaNNT> Pd-GaNNT> Pt-GaNNT. The potential applications of M-GaNNT in gas sensor and adsorbent are then predicted through the analysis of the adsorption energy, sensitive response (SR) and recovery time (τ). Pb-GaNNT performs the best Cl2 gas removal since the largest Eads (-5.883 eV), largest SR (4.4 × 1015) and largest τ (2.9 × 1087s) can be determined for Cl2 adsorption on Pb-GaNNT. Furthermore, Pb-GaNNT is a good NH3 gas sensor since the related τ is only 2.9 s at 498 K, and a small Eads (-1.232 eV) with large SR (9.7 × 105) can be determined as well. The research findings in this paper provide a new sensor material option for both the detection and the removal of harmful gases, and the systematically theoretical method can spread to other systems.

Oxygen Measurement in Cuprate Superconductors Using the Dissolved Oxygen/Chlorine Method

We have developed a dissolved oxygen (DO) method with differential equation (DE) correction. We measured the oxygen content in La-based and Y-based superconductors, and succeeded in measuring the oxygen content simply in one-third of the time required by the iodometric titration method. However, there was a problem with Bi-based superconductors where the measured oxygen content was smaller compared to the iodometric titration method. We hypothesized that not only O2 but also Cl2 gas is generated when dissolving Bi-based superconductors and developed a dissolved oxygen/chlorine (DO/Cl) method with DE correction. This method uses only a dissolved oxygen sensor and a dissolved chlorine sensor to measure the dissolved oxygen and dissolved chlorine content in Bi2Sr2−xLaxCuOy, allowing for the calculation of copper valence and oxygen content. The results from the DO/Cl method with DE correction show that the measured copper valence and oxygen content differ very little from those obtained using the iodometric titration method, with discrepancies within 0.016 and 0.008, respectively. Additionally, this method reduces the measurement time by one-third compared to the iodometric titration method. The results demonstrate that the DO/Cl method with DE correction can effectively measure the copper valence and oxygen content in cuprate superconductors, and using hydrochloric acid as the experimental solution is superior to sulfuric acid and nitric acid.

Li-decorated B12C6N6 hybrid nanocage for sensing Cl2, COCl2, H2S and NH3 gas molecules

We examined the gas sensing abilities of Li-decorated B12C6N6 (B12C6N6Li) hybrid nanocage, introducing B12C6N6 for the first time in sensing applications. The toxic gas molecules like Cl2, COCl2, H2S, and NH3 were considered. The B12C6N6 nanocage with C2V symmetry displayed the lowest energy among its isomers. Li exhibited stronger anchoring above B3C2N ring compared to B2C2, B2N2, and B3CN2 rings of B12C6N6 nanocage, displaying a binding energy of −3.30 eV. Li decoration resulted in asymmetric spin-up and spin-down states near Fermi level, indicating magnetic nature of complexes. B12C6N6, an electron-deficient nanocage, displayed charge transfer from Li atom to the nanocage. Substantial changes in electronic states occurred following the adsorption of Cl2 and COCl2 molecules. COCl2, H2S, and NH3 adsorption is thermodynamically favourable over a wide temperature and pressure range, while Cl2 adsorption is favourable only within a confined range. Earlier findings indicate dissociative adsorption of Cl2 on nanocages rendering the substrate to be non-reusable. B12C6N6Li considered here is superior over other nanocages as Cl2 adsorbs in molecular form while B12C6N6Li also demonstrates significant sensitivity. B12C6N6Li nanocage is unsuitable for sensing H2S and NH3 gas molecules but holds promise as a potential candidate for sensing Cl2 and COCl2 gas molecules.

First-principles study of CH2O, CH4, Cl2, HCN, and CNCl gas adsorption behavior by h-BN boron site modification

The potential application of metallic boron bit-doped hexagonal boron nitride monolayers (h-BN@M, M = Fe, Sn, Cu, Zn) as materials for the detection of hazardous gases (CH2O, CH4, Cl2, HCN, and CNCl) has been investigated based on the first nature principle. h-BN@Fe exhibits chemisorptive properties for the adsorption of HCN and CNCl and h-BN@Sn exhibits chemisorption and appropriate humidity resistance. The recovery time of HCN on the h-BN@Fe surface and CNCl on the h-BN@Sn surface was significantly shortened under the 392 K ultraviolet light attempt frequency. In the presence of an applied electric field, HCN and CNCl on the h-BN@Fe surface and CNCl on the h-BN@Sn surface showed adjustable recovery times. This suggests that it is possible to design gas sensing devices with good adsorption characteristics on metallic boron bit-doped hexagonal boron nitride monolayers. In the future, the performance of these materials for the detection of hazardous gases will be improved by changing their structure and composition.

Unveiling the dual tunability of dimension and pore structure in MAX-derived carbon via molten salt electrolysis

3D construction or pore-forming of carbon nanosheets brings the materials exceptional energy storage performance. However, these strategies involve complicated procedures and challenging conditions. Herein, based on the structural regulation of a MAX phase, a facile method was proposed to prepare MAX-derived carbon (MDC) with dual tunability of dimension and pore structure via molten salt electrochemical etching-gaseous sulfur delamination coupling. Polyhedral structure Ti2SC and highly oriented structure Ti2SC were transformed into 3D Mesopore carbon nanoshells (3D Meso-CNSL) and 2D Mesopore carbon nanosheets (2D Meso-CNST) in one step. By matching the decomposition voltage of TiClx with that of PS-Ti2SC, Cl2 gas generated in situ was employed to enhance the porosity of the 3D Meso-CNSL, resulting in the formation of 3D meso/macro-porous carbon nanoshells (3D Meso/Macro-CNSL) with doubled pore volume (1.45 cm3 g−1) and specific surface area (649.97 m2 g−1). The 3D Meso/Macro-CNSL exhibits excellent capacity performance and cycle stability under high current density. The capacities are 674.8 mAh g−1 and 501.5 mAh g−1 after 1000 cycles at 5 A g−1 and 10 A g−1, respectively. It is the first report on the direct delamination of MAX phases into 3D nanomaterials, presenting a new pathway for the precise regulation of the nanostructure of the MDCs.

Adsorption and reversible detection of toxic halogens gases at room temperature by two-dimensional Al2SSe for occupational sustainability

Current treatment for inhalational halogens poisoning involves providing supportive care, which includes administering humidified oxygen and managing the airway. Since toxic effects of halogens cannot be reversed, sensors with high sensitivity and good reversibility for detecting the relatively lower concentration yet noxious halogens becomes particularly significant and enticing. Herein, the structural and optoelectronic properties of toxic F2 and Cl2 gas molecules adsorbed on highly stable Al2SSe monolayer have been systematically studied by means of first-principles calculations based on density functional theory (DFT). Favorable adsorption sites of said molecules on Al2SSe were carefully examined. The relatively high, negative adsorption energy for F2 and Cl2 indicate that the adsorption process is exothermic and the molecules could be stably adsorbed on Al2SSe monolayer. This characteristic, combined with the substantial charge transfer (0.15–0.55 |e|), drastic change in work function, complete reversibility due to recovery time in 10−1 s scale and distinct optical response, render Al2SSe monolayer a viable option for utilization as either surface work functions transistor or optical chemical resistor for detecting these gases. Pearson correlation coefficient (PCC) analysis of theoretical recovery time and response value indicates that band gap change and electron transfer are the primary influencing factors. Selectivity analysis reveals that common compound forms of halogens and atmospheric molecules such as HF, HCl, N2, O2, H2 and H2O are either physically adsorbed or inert with extremely low adsorption energies on Al2SSe, prompting high F2 and Cl2 selectivity. These outcomes acclaim the exciting prospects of developing Al2SSe monolayer for specific, occupational related ultrahigh-sensitivity F2 and Cl2 sensing nanodevices.

Construction of bayberry-like Cu2O/CuO and detection of trace Cl2 at low temperature

The effective detection of toxic and harmful gases is of great significance for protecting the environment and human health. The construction of heterostructures plays a crucial role in improving gas sensing performance of sensitive materials. In this study, an one-step solvothermal method was used to directly synthesize ∼2 μm bayberry-like Cu2O/CuO. Due to the formation of heterostructures, the gas sensing performance of the material is effectively improved. The optimal sensor based on Cu2O/CuO exhibits good gas sensing performance (S=45) to 10 ppm Cl2 at 50 ℃, with a detection limit as low as 300 ppb (S=1.33), good selectivity and reproducibility. Its excellent gas sensing performance can be attributed to the presence of oxygen vacancies in the material and the synergistic effect between Cu2O/CuO heterostructure components. The presence of oxygen vacancies increases the adsorption of oxygen ions on the material surface. The formation of heterostructures not only regulates the electronic structure of CuO, but also provides more adsorption sites for the target gas. Therefore, the bayberry-like Cu2O/CuO material can be used as a candidate sensitive material for low-temperature Cl2 gas detection.

Copper and Aluminium Electrochemical Corrosion Investigation during Electrolysis and Heating from 20oC to 180oC

Our investigations show that electrochemical corrosion of copper is faster than electrochemical corrosion of aluminium at temperatures below 180°C and electric current density 3,000 A/m2 (or 30 A/dm2=3 mA/mm2). We have obtained that aluminium anodes (cylindrical or spherical) dissolve into concentrated NaCl solution during electrolysis more rapidly with temperature increasing while copper anodes (cylindrical or spherical) dissolve more slowly with temperature increasing from room temperature to temperature 180°C. Electric current value also increases with temperature increasing. Really, such result is unexpected. General quantity of the H+ and Cl- ions decreases during electrolysis at all temperatures since the H2 and Cl2 gases are formed near electrodes. It decreases electric current value on 1.3%. General quantity of the Cu+ and Cu2+ ions decreases with temperature increasing too. We guess that one reason only should be for electric current value increasing: average charge of copper ions increases from +1 at room temperature to +1.5 at 100°C and to +2 at 180°C while charge of aluminium ions remains the same +3. Corresponding mathematical model is proposed for the analysis, and literature experimental data are used too.

Hemopexin reverses activation of lung eIF2α and decreases mitochondrial injury in chlorine-exposed mice.

We assessed the mechanisms by which nonencapsulated heme, released in the plasma of mice after exposure to chlorine (Cl2) gas, resulted in the initiation and propagation of acute lung injury. We exposed adult male and female C57BL/6 mice to Cl2 (500 ppm for 30 min), returned them to room air, and injected them intramuscularly with either human hemopexin (hHPX; 5 µg/g BW in 50-µL saline) or vehicle at 1 h post-exposure. Upon return to room air, Cl2-exposed mice, injected with vehicle, developed respiratory acidosis, increased concentrations of plasma proteins in the alveolar space, lung mitochondrial DNA injury, increased levels of free plasma heme, and major alterations of their lung proteome. hHPX injection mice mitigated the onset and development of lung and mitochondrial injury and the increase of plasma heme, reversed the Cl2-induced changes in 83 of 237 proteins in the lung proteome at 24 h post-exposure, and improved survival at 15 days post-exposure. Systems biology analysis of the lung global proteomics data showed that hHPX reversed changes in a number of key pathways including elF2 signaling, verified by Western blotting measurements. Recombinant human hemopexin, generated in tobacco plants, injected at 1 h post-Cl2 exposure, was equally effective in reversing acute lung and mtDNA injury. The results of this study offer new insights as to the mechanisms by which exposure to Cl2 results in acute lung injury and the therapeutic effects of hemopexin.NEW & NOTEWORTHY Herein, we demonstrate that exposure of mice to chlorine gas causes significant changes in the lung proteome 24 h post-exposure. Systems biology analysis of the proteomic data is consistent with damage to mitochondria and activation of eIF2, the master regulator of transcription and protein translation. Post-exposure injection of hemopexin, which scavenges free heme, attenuated mtDNA injury, eIF2α phosphorylation, decreased lung injury, and increased survival.

Electrocoagulation Coupled to Electro-Oxidation for the Electrochemical Treatment of Hemodialysis Wastewater

Hemodialysis is an extracorporeal kidney replacement procedure to remove impurities or waste products from the blood used to treat kidney failure. During this process, large amounts of water are used, which, lacking control, end up in sewage systems, potentially flushing high levels of organic and inorganic contaminants into the receiver’s aqua biota. In recent years, a hybrid electrocoagulation (EC) and electro-oxidation (EO) process in sequential or simultaneous coupling has been used for the treatment of wastewater.This research considered synthetic water from hemodialysis under acid and basic conditions. To better simulate the presence of organic compounds, 10 mg L-1 of amoxicillin (AMX), an antibiotic commonly present in wastewater from clinics and hospitals, was added. Laboratory and pilot tests were performed using coupled EC and EO. They used stainless-steel (SS-304) and aluminum (Al-6061) as sacrificial anodes that were compared in acidic and basic pH during EC. The SS-304 rod anode and a titanium (Ti) mesh cathode were used during EC in acidic conditions at a field strength of 3.0 V, which was applied for 60 min. After EC, the solution obtained was filtered to separate precipitates. The supernatant was then treated with EO using an IrO2-Ta2O5|Ti (70:30) anode and the Ti mesh cathode while applying 10 mA for 120 min. The wear of the SS-304 anode was identified by scanning electron microscopy (SEM) and microanalysis (EDS). Removal of organic compounds, including AMX, was significant. This result was confirmed by decreased concentration found by diode coupled chromatography (UPLC-UV-Vis) detection.In conclusion, combining EC and EO in a sequential arrangement for the treatment of hemodialysis wastewater was carried out. EC was performed using a cylindrical SS-304 bar electrode (f = 0.8 cm) as an anode and a concentric Ti mesh as the counter electrode. A 3.0 V cell potential was maintained over one hour of electrolysis in acidic pH (pH = 5.06, s = 227 mS cm-1). This treatment yielded a removal efficiency of 86 ± 1.25 % of AMX contaminate (pH = 8.21, s = 217.26 mS cm-1, i = 11.36 mA, E = 0.568 kWh m-3). After EC, it was necessary to include a filtration or separation process to remove the Fe(OH)3 and [AMX-cation-AMX] sludge generated (2.3 g). This separation employed a settler. Subsequently, the supernatant was placed in an EO cell to remove residual organic compounds as AMX. It used a similar cell arrangement as in EC but changed the anode to IrO2-Ta2O5|Ti (70:30) (f = 0.5 cm) to perform the EO of the pharmaceutical product. During this step, the team achieved an overall removal efficiency of AMX of 100 % (pH = 8.14, s = 179.83 mS cm-1, E = 500 kWh m-3). EO was performed using a continuous 10 mA cell current for 2 h. EO generated reaction products ADP 1, ADP 2, and ADP 3. Additionally, this process decreased the content of ‘salty’ cations: Na+, K+, Ca2+, and Mg2+, while generating Cl2 gas at the electrode.

Si[formula omitted]BN nanosheets as anchoring cathode material for realizing high capacity Al-ion battery

Identifying a stable and high-capacity cathode material is crucial for the practical implementation of Aluminium-ion batteries (AIBs). Using first-principles calculations, we propose Si2BN as a suitable cathode material for AIBs. We show that sp2 hybrid Si2BN nanosheets with polar-covalent bonding nature favour the adsorption of a large number of AlCl4 clusters with significant charge transfer that results in a higher adsorption strength and stability compared to non-polar carbon cathodes. The estimated theoretical specific capacity (TSC) of Si2BN is 330 mAh/g, which is six times higher than that of graphite. Bilayer studies reveal that Si2BN shows surface adsorption of AlCl4 similar to that of the monolayer, but intercalation at low concentration of AlCl4 is unfavourable and it also shows that the binding strength of AlCl4 significantly improves when we first adsorb AlCl4 on the outer layers of Si2BN and then intercalate it between the layers. The nudged elastic band (NEB) study elucidates an easy diffusion of AlCl4 along the two-dimensional sheet with a barrier of 0.19−0.22 eV. Thermodynamical stability analysis implies the absence of more serious Cl2 gas evolution that makes Si2BN a durable cathode material. Hence, the proposed Si2BN has a great advantage over carbonaceous cathodes for designing high energy density and quick charge AIBs.

Rates of cylindrical and spherical copper anodes dissolving into concentrated NaCl water solution calculation during electrolysis and temperature increasing

Our experimental investigations show that rate of copper anodes degradation decreases during electrolysis in concentrated NaCl solution in water (5 mol/kg or 23 %, freezing point equals −22°C, pH 6.5–7.5) at electric current density about 3000 A/m2 (or 30 A/dm2 = 3 mA/mm2) with temperature increasing from room temperature to 100 °C. Electric current value also increases with temperature increasing. Really, such result is unexpected. General quantity of the H+ and Cl− ions decreases during electrolysis at all temperatures since the H2 and Cl2 gases are formed near electrodes. General quantity of the Cu+ and Cu2+ ions decreases with temperature increasing too. We guess that one reason only should be for electric current value increasing: average charge of copper ions increases from +1 at room temperature to +1.5 at 100 °C and to +2 at 180°C. Corresponding mathematical model is proposed for the analysis. Literature experimental data are used too.

Probe and Spectral Diagnostics of the Plasma of the BCl3–Cl2 Gas Medium

Probe and Spectral Diagnostics of the Plasma of the BCl3–Cl2 Gas Medium

Rechargeable Hydrogen-Chlorine Battery Operates in a Wide Temperature Range.

Hydrogen-chlorine (H2-Cl2) fuel cells have distinct merits due to fast electrochemical kinetics but are afflicted by high cost, low efficiency, and poor reversibility. The development of a rechargeable H2-Cl2 battery is highly desirable yet challenging. Here, we report a rechargeable H2-Cl2 battery operating statically in a wide temperature ranging from -70 to 40 °C, which is enabled by a reversible Cl2/Cl- redox cathode and an electrocatalytic H2 anode. A hierarchically porous carbon cathode is designed to achieve effective Cl2 gas confinement and activate the discharge plateau of Cl2/Cl- redox at room temperature, with a discharge plateau at ∼1.15 V and steady cycling for over 500 cycles without capacity decay. Furthermore, the battery operation at an ultralow temperature is successfully achieved in a phosphoric acid-based antifreezing electrolyte, with a reversible discharge capacity of 282 mAh g-1 provided by the highly porous carbon at -70 °C and an average Coulombic efficiency of 91% for more than 300 cycles at -40 °C. This work offers a new strategy to enhance the reversibility of aqueous chlorine batteries for energy storage applications in a wide temperature range.

Electron regulation and gas-sensitivity analysis of hBN-Graphene lateral heterojunctions——First principle study

In this paper, the first-principle calculations of the lateral heterojunction model synthesized by hBN-Graphene were carried out, and it was found that the bandgap of graphene varied with the change in the proportion of hBN, and the bandgap was best regulated with a bandgap of 1.177 eV when the proportion of hBN was 66.67 %. At this time, the adsorption structures of HCN, CO, NH3, and Cl2 were established and energy band calculations were performed on the hBN and Graphene portions of the hBN-Graphene lateral heterojunctions, respectively, and it was found that the adsorption of Cl2 resulted in a significant change in the band gap, which showed a very high electrical sensitivity. To further investigate the adsorption mechanism of Cl2 on the surface of hBN-Graphene lateral heterojunction, the energy band structure, PDOS, charge transfer, adsorption energy, and recovery time of each stabilized adsorption site of Cl2 on the surface of hBN-Graphene lateral heterojunction were calculated. The results show that the adsorption of Cl2 on the surface of hBN-Graphene lateral heterojunction is a stable chemisorption, and the band gap of C-Top1 increases to 1.274 eV, and the band gaps of C-Top3, N-Top1, and N-Top2 decrease to 0.684 eV, 0.376 eV, and 0.398 eV, respectively, and the changes of band gaps are significant and easy to be electrically detection. The recovery time of Cl2 on the surface of hBN-Graphene lateral heterojunction was 7.36 s–2.59 s in visible light and in the temperature interval of 273 K–283 K. The recovery time of Cl2 on the surface of hBN-Graphene lateral heterojunction was 7.36 s–2.59 s in visible light and in the temperature interval of 273 K–283 K. These findings have implications for the research and application of graphene-based Cl2 gas sensors.

Correlation between EMF and Gibbs Free Energy, and the Relative Concentration of Electrolytes in a Concentration Cell

The experiment aimed at establishing a link between the varying concentration of the electrolyte in one half-cell of a concentration cell and the resulting EMF generated across the cell. Further, it also drew a connection between this variation and the change in Gibbs free energy for the electrochemical reaction. The change in Gibbs free energy calculated for the electrochemical reaction for each C2 value indicated a decreasing trend with an increasing C2 concentration. It was thus observed that as C2 increased, or the difference in concentrations of the two electrolytes decreased, the spontaneity of the reaction decreased. Reduction occurs at the negatively charged cathode and oxidation occurs at the positively charged anode. Here, aqueous NaCl is undergoing electrolysis – where the Cl-1 ions are attracted to the positive anode and get oxidized due to the loss of electrons and emerge as chlorine Cl2 gas.

Density functional theory study on gas-sensing property of (SnO2)n (n = 1–3) modified MoTe2 towards chlorine, ammonia, and sulphur dioxide upon diesel-driven vehicle

Chlorine (Cl2), ammonia (NH3), and sulphur dioxide (SO2) are three typical toxic gases of tank-vehicle transportation. it is necessary to conduct online detection of these gases to ensure transportation safety and exhaust emission monitoring. In this study, tin dioxide (SnO2)n (n = 1–3) modified molybdenum (IV) telluride (MoTe2) monolayer were selected to explore its adsorption characteristics towards Cl2, NH3, and SO2 gases. All calculations are based on density function theory, geometric structure, charge transfer, adsorption energy, the density of states, and molecular orbitals were taken into account to compare and analyze the adsorption performance of the gas-sensing material before and after surface modification. The results show that these three gases are physically adsorbed on the intrinsic material. The modified (SnO2)n (n = 1–3) are all stably bound to the MoTe2 surface. For both Cl2 and NH3, the adsorption energies are in order of SnO2-MoTe2 > (SnO2)2-MoTe2 > (SnO2)3-MoTe2. And the adsorption energies for SO2 can be ranked as (SnO2)3-MoTe2 > SnO2-MoTe2 > (SnO2)2-MoTe2. The significant changes in electrical conductivity indicate the modified MoTe2 system consistently showed excellent sensitivity to the three gases. Therefore, the (SnO2)n-modified MoTe2 system is expected to be a candidate gas-sensing material for Cl2, NH3, and SO2, opening up a new perspective on MoTe2 in the field of gas detection.