Thiophene Research Articles

Carboxylic acid-based deep eutectic solvent for efficient desulfurization: Experimental and computational thermodynamics

The improvement of fuel quality requires the reduction of sulfur content. The main challenge of catalytic cracking diesel extraction desulfurization is to find low-price and good-performance extractants. Based on experimental research, this work further explores the separation mechanism of DES for thiophene (TP) and benzothiophene (BTP). First, the COSMOS-RS model was used to predict the separation performance of 10 HBAs and 10 HBDs for TP and BTP. The results showed that the low-cost carboxylic acid based DES had excellent separation performance. Secondly, the effect of experimental conditions on the separation performance of three carboxylic acid based DESs was investigated. When the molar ratio of DES to TP and BTP was 3:1, after three stage extraction, the extraction rates of TP and BTP by TEAC: PrA(1:3) were 98.06 % and 98.53 %, respectively. Finally, the structure–activity relationship was studied by using quantum chemistry and molecular dynamics simulation. It was found that EvdW plays a dominant role in the desulfurization process and does not include H-bond interactions. TEA+ was distributed parallel to the aromatic ring and has a CH···π interaction with thiophene. TP and BTP were distributed in the voids of DES and do not affect the regeneration performance of DES.

Facile loading of CuCl on SBA-15 for adsorptive desulfurization

SBA-15 supported CuCl (CuCl/SBA-15) adsorbents were prepared with CuCl2 as precursor via a facile ethylene reduction, where the reduction of CuCl2 was carried out at temperatures ranging from 120 to 220 °C. The prepared adsorbents were characterized by X-ray diffraction, N2 adsorption-desorption, Transmission electron microscopy, and X-ray photoelectron spectroscopy. The characterization reveals that the CuCl2 supported on SBA-15 can be reduced to CuCl, and the ratio of Cu+ to the total copper amount increases with increasing the reduction temperature, reaching 85.7 % at 200 °C. The adsorption capacities of thiophene (TP), benzothiophene (BT) and dibenzothiophene (DBT) over the CuCl/SBA-15(x) were further tested at 30 °C, and the Langmuir equation was used to fit the adsorption isotherms. It shows that their adsorption capacities of desulfurization follow the order of CuCl/SBA-15(200) > CuCl/SBA-15(180) > CuCl/SBA-15(150) > CuCl/SBA-15(120) > CuCl/SBA-15(220). The CuCl/SBA-15 (200) outperforms the other samples, and its adsorption capacities are up to 40.83 mg S/g for TP, 56.10 mg S/g for BT, and 81.23 mg S/g for DBT, respectively. The regeneration experiments for CuCl/SBA-15(200) show that the desulfurization performance was still maintained after four adsorption-desorption cycles.

Effects of Connectivity Isomerization on Electron Transport Through Thiophene Heterocyclic Molecular Junction.

Connectivity isomerization of the same aromatic molecular core with different substitution positions profoundly affects electron transport pathways and single-molecule conductance. Herein, we designed and synthesized all connectivity isomers of a thiophene (TP) aromatic ring substituted by two dihydrobenzo[b]thiophene (BT) groups with ethynyl spacers (m,n-TP-BT, (m,n = 2,3; 2,4; 2,5; 3,4)), to systematically probe how connectivity contributes to single-molecule conductance. Single-molecule conductance measurements using a scanning tunneling microscopy break junction (STM-BJ) technique show ∼12-fold change in conductance values, which follow an order of 10-4.83 G0 (2,4-TP-BT) < 10-4.78 G0 (3,4-TP-BT) < 10-4.06 G0 (2,3-TP-BT) < 10-3.75 G0 (2,5-TP-BT). Electronic structure analysis and theoretical simulations show that the connectivity isomerization significantly changes electron delocalization and HOMO-LUMO energy gaps. Moreover, the connectivity-dependent molecular structures lead to different quantum interference (QI) effects in electron transport, e.g., a strong destructive QI near E = EF leads the smallest conductance value for 2,4-TP-BT. This work proves a clear relationship between the connectivity isomerization and single-molecule conductance of thiophene heterocyclic molecular junctions for the future design of molecular devices.

Diatomite supported bagel-like hydroxylated mesoporous carbon nitride towards the adsorption desulfurization application

The carbon nitride (g-C3N4) nanosheets was apt to occur the donor-acceptor (D-A) interaction with the sulfides via the influence of the electronic structure of C atoms in the ring. Accordingly, we implemented an environmental- friendly approach to raise the electropositivity of the C atoms of N atoms in the ring of g-C3N4 through the hydroxylation treatment of hydrogen peroxide(H2O2), and afterwards constructed a bagel-like morphology composite ((HO)x/g-C3N4@DE) by virtue of the calcined combination of hydroxylated mesoporous g-C3N4 and diatomite (DE). The characterization results showed that the substantial mesoporous structure was produced in the formation of (HO)x/g-C3N4@DE composite. The adsorption desulfurization experiments showed that the bagel-like hydroxylated mesoporous (HO)x/g-C3N4@DE had the optimum adsorption capacity of up to 42.2 mg/g for thiophene (TH) and 30.8 mg/g for benzothiophene (BT), respectively. Moreover, the adsorption capacities of the hydroxylated mesoporous (HO)x/g-C3N4@DE were dramatically higher than the individual (HO)x/g-C3N4 (18.92 mg/g for TH and 15.64 mg/g for BT), suggesting that the occurrence of the secondary stacked mesopores in the formation of the (HO)x/g-C3N4 on the surface and macro-porous structure of DE affected the adsorption capacity. Lastly, the adsorption mechanism of the hydroxylated mesoporous (HO)x/g-C3N4@DE was proposed.

Facile construction of hierarchically porous CPO-27-Ni by mixed ligand strategy towards enhanced adsorption desulfurization from fuels

High-efficiency removal of macromolecular aromatic sulfide from fuel via adsorption technology remains a challenge due to the limited mass-transfer efficiency in traditional microporous materials. Constructing hierarchically porous structure might be an alternative route to overcome the problem. Herein, we propose an approach to prepare rationally defective Nickel(II) 2,5-dihydroxyterephthalate (CPO-27-Ni) using benzoic acid (BA) and 2, 5-dihydroxyterephthalic acid (DHTA) as mixed ligands, aiming at reducing the diffusion resistance of molecules in adsorbents through introducing mesopores and thus enhancing the performance of aromatic sulfide removal. By adjusting the ratio of BA and DHTA (x), CPO-27-Ni (BA-C-x) with rational defects was successfully synthesized. Compared with the single-channel CPO-27-Ni, the penetrating sulfur capacity in the dynamic adsorption experiment was increased by 9.97 times for thiophene (TP), 7.25 times for benzothiophene (BT) and 2.81 times for dibenzothiophene (DBT). After the addition of organic ligand B, additional mesoporous pores were formed in the microporous CPO-27-Ni. The obtained hierarchical structure possessed better textural properties and ensured structural constancy, which improved the utilization rate of high active sites and mass transfer rate of adsorbent, leading to promoted desulfurization performance. The reported method of introducing mesopores into MOFs to construct hierarchically porous structures would provide a meaningful reference for facile preparation of high-efficiency desulfurization adsorbents.

Polymer donors based on alkyloxime‐substituted thiophene and 6‐undecylthiopheno[3,2‐b]thiophene for efficient organic solar cells

AbstractTwo new copolymers (named PTO‐BO and PTO‐HD) with alkyloxime‐substituted thiophene (TO) as acceptor unit and 6‐undecylthiopheno[3,2‐b]thiophene spacer as π‐bridge were synthesized and applied in organic solar cells (OSCs) as electron donors. PTO‐HD with 2‐hexyldecyl side chains on TO moiety possesses more suitable phase separation, more efficient exciton dissociation and charge transportation, and less charge recombination than PTO‐BO with 2‐butyloctyloxime‐substituted thiophene in OSCs with Y6 as the acceptor. As a result, the OSCs based on PTO‐HD:Y6 achieved an optimal power conversion efficiency (PCE) of 13.89% with a Voc of 0.799 V, a Jsc of 22.74 mA cm−2, and a FF of 67.67% without additives, which is higher than that (12.29%) of PTO‐BO:Y6 OSCs.

The powerful combination of 2D/2D Ni-MOF/carbon nitride for deep desulfurization of thiophene in fuel: Conversion route, DFT calculation, mechanism

2D/2D Ni-MOF/g-C3N4 nanocomposite was utilized for desulfurization. The multilayer pore structure and high specific surface area of Ni-MOF/g-C3N4 promote the adsorption and conversion of thiophene. In addition, the two-dimensional structure exposes more active centers and shortens photogenerated carrier migration to the material surface distance, it enhances photogenerated charge transfer. The Ni-MOF and g-C3N4 construct a Z-scheme heterojunction structure with tight contact, it effectively enhances the material's photocatalytic redox ability. In the light, the material generates more photocarriers for the production of free radicals including hydroxyl radicals, holes, and superoxide radicals. The higher carrier concentration of Ni-MOF/g-C3N4 promotes the activation and oxidation of thiophene, consequently enhancing the photocatalytic desulfurization capability. The results showed that the conversion of thiophene was 98.82 % in 3 h under visible light irradiation. Radical capture experiments and analysis using electron paramagnetic resonance spectroscopy demonstrated that superoxide radicals, holes, and hydroxyl radicals played crucial roles in PODS (photocatalytic oxidative desulfurization). In addition, DFT (density functional theory) calculations were conducted to determine the paths of electron migration and TH (thiophene) adsorption energy. Finally, a mechanism for photocatalytic desulfurization was proposed based on the comprehensive analysis of theoretical calculations and experimental studies.

In situ synthesis of mesoporous NiS2-MoS2 sphere-flower hybrid for hydrodesulfurization of thiophene and 4,6-dimethyl-dibenzothiophene

A series of new NiS2-MoS2-x (x = 0–0.5) sphere-flower hybrids with different Ni/Mo molar ratios, synthesized via a one-pot hydrothermal method, were used as catalysts for hydrodesulfurization (HDS) of thiophene (TP) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT). The characterizations show that the microstructure of MoS2, including the size of MoS2 nano-flowers, the length of MoS2 slabs, and the number of defects, was regulated by changing Ni/Mo ratios. Increasing the Ni/Mo ratio in the NiS2-MoS2-x catalysts significantly boosts their HDS activity, with the optimum ratio being 0.2. In addition, the NiS2-MoS2-0.2 catalyst exhibits the best direct desulfurization performance, which is associated with the minimum ratio of average slab length (Lav) to average stacking number (Nav) as well as the highest concentration of Ni-promoted Mo sites and sulfur vacancies. Moreover, Ni-containing NiS2-MoS2-x catalysts, characterized by a highly stable sphere-flower configuration, exhibit superior structural stability and catalytic durability than the Ni-free NiS2-MoS2-0 catalyst.

Photocatalytic oxidative demercaptanization/denitrogenation of gasoline catalyzed by MAX-phase@rGO@PW11Zn as a high-performance nanocatalyst

The new catalyst (assigned as MAX-phase@rGO@PW11Zn) was prepared based on [(n‐C4H9)4N][PW11ZnO39] (PW11Zn), Ti3AlC2 (MAX-phase), reduced graphene oxide (rGO) and used in photocatalytic oxidative denitrogenation (photocatalytic-ODN) and demercaptanization (photocatalytic-ODS). The photocatalysis process adjusted to demercaptanization of real gasoline and oxidation of model fuel (thiophene (TH) and pyridine (PY)). Intercalation effect of PW11Zn to Ti3AlC2 MAX-phase and reduced graphene oxide accelerate electron transfer and prevent the recombining of electron-hole pairs. MAX-phase@rGO@PW11Zn catalyst exhibited enhanced photocatalytic application and excellent reusability in the elimination of TH and PY, and producing ultra-clean fuels: 97.72% and 98.94% efficiency were achieved for thiophene (TH) and pyridine (PY), respectively at 35 °C. The good activity of MAX-phase@rGO@PW11Zn/H2O2/CH3COOH proves that this photocatalytic system can be a promising strategy for a high-performance catalyst for the generation of ultra‐low‐sulfur gasoline.

Conjugated porous polymers regulated by thiophene and polycyclic aromatic hydrocarbons for photocatalytic water splitting toward hydrogen production

Rational design of organic semiconductors with wide visible light absorption and quick charge separation is of great significance for photocatalytic hydrogen production form water. In this work, the chemical structure of a linear conjugated polymer composed of ethynyl-linked benzene (B) and 2,1,3-benzothiadiazole (BT) is regulated by thiophene (TP) and polycyclic aromatic hydrocarbons [naphthalene (N) and anthracene (A)], and series of polymers including B-BT-TP-x, N-BT-TP-x and A-BT-TP-x (x = 0.2, 0.4, 0.6, 0.8) are synthesized. After thiophene and polycyclic aromatic hydrocarbon regulation, the polymers exhibit strong absorption in the whole visible light region of 400->650 nm and quick internal charge separation and transfer. Visible-light-driven photocatalytic hydrogen production rates of the synthesized polymers follow the order of B-BT (170.0 μmol/h) < B-BT-TP-0.6 (735.3 μmol/h) < N-BT-TP-0.4 (841.5 μmol/h) < A-BT-TP-0.6 (969.2 μmol/h) using 30 mg catalyst with 1.0 wt% Pt as cocatalyst. In addition, high apparent quantum yield (AQY) values of 8.04%, 5.58% and 0.95% under 550 nm, 650 nm and 700 nm monochromatic lights are obtained using A-BT-TP-0.6 catalyst. The present work provides new insights into design of advanced organic semiconductors for highly efficient photocatalytic solar energy conversion.

Experimental and molecular dynamics study of fuel desulfurization process using deep eutectic solvent

The sulfur-containing compounds in China's crude oil mainly exist in the form of thiophene (TPs). More than 80% of TPs are composed of dibenzothiophene (DBT). The combustion of sulfur-containing fuel oil pollutes the air. Studies have shown that DES, as a new solvent similar to ionic liquids, has the advantages of simple preparation, easy availability of raw materials and high extraction rate. In this paper, experiments on DES synthesis were carried out to screen DES with the best extraction efficiency, and the effects of extraction operation temperature and initial sulfur concentration of raw oil on DES extraction and desulfurization were explored. The DES separation mechanism for DBT extraction from n-heptane-DBT was used as the simulated oil. Quantum chemistry was calculated for 9 commonly used DES, and the hydrogen bonding between DES-DET-n-heptane was analyzed by using the obtained σ-Profiles map information, and the selected DES was compared with the auxiliary experiment from the perspective of quantum chemistry. Then, the molecular dynamics (MD) simulation between different DES and raw oil was carried out, that is, the non-bond interaction energy, radial distribution function, spatial distribution function and mean square shift results of DBT-Heptane-DES calculated by molecular dynamics were used to deeply analyze the microscopic separation mechanism of DES extraction desulfurization. The results show that the DES composed of choline chloride/diethylene glycol can theoretically perform more efficient desulfurization operations, and this theoretical analysis method can provide a strong basis for the desulfurization of other types of DES and the separation of other systems.

Microwave-assisted rapid growth of corncob-like nano-Ag2O/ZIF-8 on PAN electrospinning nanofibers enabled highly efficient selective adsorption desulfurization

The higher energy consumption and processing cost greatly constricted the extensive application of the adsorption desulfurization technique. Herein, the nano-Ag2O/ZIF-8@ polyacrylonitrile (PAN) nanofiber membrane (NFM) was successfully made by using electrospinning and microwave-assisted synthesis. The characterizations demonstrated that the nano-Ag2O-dotted ZIF-8 with the exclusive corncob-like structure uniformly grew on the surface of PAN nanofiber. The in-situ fabrication of nano-Ag2O/ZIF-8 on the surface of PAN nanofiber was rapidly realized by microwave-assisted method, thus resulting in the less loss of the mechanical performance of NFM. The tests indicated that the tensile strength and young's modulus of Ag2O/ZIF-8@PAN NFM were 35 % and 185 % higher than PAN NFM, respectively. The fabrication of the multi-pore structure endowed the Ag2O/ZIF-8@PAN NFM to achieve the superior adsorption performance for thiophene (TH) from fuel oil, having the increase by 312 % and 175 % in the batch adsorption (maximum: 37.142 mg·g−1) and fixed-bed breakthrough adsorption (maximum: 35.423 mg·g−1) capacities compared to PAN NFM, respectively. Furthermore, the saturated adsorption capacity of Ag2O/ZIF-8@PAN NFM in fixed-bed adsorption experiment was higher than those of Cu2O-doped PAN NFM (4.571 mg·g−1) and Ag2O@HNTs-doped PAN NFM (31.982 mg·g−1) reported by our previous study. The adsorption mechanism of TH molecules on the Ag2O/ZIF-8@PAN NFM was explored by the kinetics, intra-particle diffusion, isotherms and thermodynamic models, which affirmed to exist the synergistic effect of physical adsorption, and chemical adsorption including π-complexation interaction and S-M interaction adsorption. Finally, this work provided a novel prospective adsorption desulfurization based on the membrane separation.

Experimental investigation of the desulfurization of a high sulfur coal with multi-ring sulfurous

ABSTRACT Coal desulfurization is imperative to produce clean coal and reduce the emission of harmful gas during combustion. However, organic multi-ring sulfurous in coal is more difficult to remove than inorganic sulfur. Therefore, in this paper, two desulfurization methods, traditional oxidation desulfurization method nitric acid leaching (NAL) and novel reduction potassium tert-butoxide and hydrogen silane desulfurization system (KOSi), were compared to remove the organic multi-ring sulfurous in raw coal sample. The results showed that the total sulfur content reductions of NAL and KOSi were 45.21% and 31.51%, corresponding to the loss rates of calorific value were 10.32% and 5.45%, respectively. The critical factors for the higher desulfurization rate of NAL than KOSi were the decreased particle size, the generation of cracks on the coal sample and the effective removal of sulfones (SN) from thiophene (TP) oxidation. In addition, the carbon macromolecular framework of coal particles could be destroyed in NAL system, resulting in a decrease in C-C and C-H content. This was the main reason that the calorific value loss of NAL was greater than that of KOSi. The consequence of this paper would provide data support for the selection of the desulfurization method for high sulfur coal, especially consisting of multi-ring sulfurous, in terms of indicators and mechanisms.

Rational design of donor-acceptor engineered g-C3N4 for boosted H2O2 production via photocatalytic O2 reduction

Artificial photo-driving 2e− oxygen reduction reaction (ORR) offers a promising strategy for H2O2 production, while the O2-to-H2O2 conversion suffers from low activity and selectivity. Herein, by grafting thiophene (TP) onto the edge of g-C3N4, we develop a donor-acceptor-engineered catalyst (g-C3N4-TP) for efficient H2O2 production. The optimized g-C3N4-TP exhibits an H2O2 production rate of 552 μmol g−1 h−1 under visible irradiation with an apparent quantum yield of 3.2 % at 420 nm, which is ca. 4 times that of pristine g-C3N4. Experiments and theoretical calculations identify that the enhanced photocatalytic performance is ascribed to the introduced TP units, which are capable of promoting the separation of electron-hole pairs, altering the adsorption mode of O2, and reducing the energy barriers for H2O2 production. This work deepens the understanding of O2 adsorption and conversion on g-C3N4, paving a new way for efficient H2O2 production by rational designing donor-acceptor-engineered photocatalysts.

Synthesis of GO/Fe–Ni MOF octahedral structure as an effective magnetic adsorbent in the removal of sulfur compounds from liquid fuel

An effective composite of bimetallic metal-organic frameworks (MOFs) GO/Fe–Ni in the presence of a specified quantity of graphene oxide (1, 5, 10, 25, and 50 wt%) was synthesized via a solvothermal method for removal of thiophene (TP) from a model of oil. The efficiency of adsorption desulfurization was evaluated by removing TP from the n-heptane-TP as a model oil. XRD, FTIR, FESEM, EDS, BET, VSM, and TGA techniques were used to investigate and confirm the structural characteristics of the GO/Fe–Ni MOF composite. The composite material of GO to Fe–Ni MOF = 5 wt% with adsorption capacity of 18.54 mg. g−1 displayed the best performance in TP at the optimal experimental conditions, which was ascribed to its high porosity and suitable pore size. GO/Fe–Ni MOF adsorption has a surface area of (431 m2. g−1) higher than Fe–Ni MOF (352 m2. g−1), based on the BET technique, there would be more opportunity for TP to be adsorbed on the GO/Fe–Ni MOF. The reused tests prove that GO/Fe–Ni MOF can be recycled for at least four runs with negligible losses in its capacity performance (11%). More significantly, the magnetic properties of GO/Fe–Ni MOF (5 wt%) can be used to facilitate the separating of oils in harsh conditions.

1,8‐diazabicyclo [5.4.0] undecano‐7‐ene functionalized ionic liquids for extractive desulfurization of fuels

AbstractBACKGROUNDWith strict regulations on environmental protection, the removal of sulfur compounds from fuels has become increasingly urgent by extraction desulfurization technology.RESULTSA series of ionic liquid (IL) extractants for the removal of sulfides [benzothiophene (BT), thiophene (TH) and dibenzothiophene (DBT) in model oil] was developed. The ILs with functionalized 1,8‐diazabicyclo [5.4.0] undecano‐7‐ene (DBU) cations and large volume difluoromethane sulfonimide (NTf2) anion as raw materials were synthesized. The performance of the ILs was characterized by Fourier transform infrared spectroscopy (FTIR), elemental analysis and nuclear magnetic hydrogen spectroscopy (1H‐NMR) and other methods. Maximum removal efficiencies of 65.08% TH, 83.02% BT and 89.72% DBT were achieved in the presence of [CoDBU][NTf2] with functionalized carboxylation groups. In addition extractive desulfurization (EDS) was studied by tailoring the acid–base functional groups and viscosity of ILs. FTIR and the analysis of interaction energies were adopted to explore the interaction of ILs and sulfides. This indicated that the cooperative effects of hydrogen bonding, electrostatic interaction and π‐π interaction between sulfides and ILs were closely related to the high removal efficiencies of sulfides.CONCLUSIONSThe experimental results show that [CoDBU][NTf2] with functional carboxyl group is a clean and efficient extractant suitable for removing thiophene sulfides from model fuel oil. This work provides a reference process for the desulfurization of fuel oil in industry. © 2022 Society of Chemical Industry (SCI).

Theoretical investigation on interactions between N-methylpyrrolidone-FeCl3 and components in model oil: The role of S-Fe coordination in thiophene removal

Metal-based coordinated ionic liquids (ILs) have drawn wide attention due to their high sulfide selectivity and desulfurization rate on extractive desulfurization (EDS). Here, a systematical investigation on the interactions between N-methylpyrrolidone-FeCl3 (NMP-FeCl3) and thiophene (TH) in the presence of model oil consisting of 1-octene (OCT), toluene (TOL), cyclohexane (CHA) and cyclohexene (CHE) was carried out using density functional theory (DFT). Three stable structures of NMP-FeCl3-TH complexes at room temperature (298 K) were taken into consideration to compare different interactions between NMP-FeCl3 and TH. The interactions were analyzed using natural bond orbital, atoms in molecules theory, independent gradient model based on Hirshfeld partition, frontier molecular orbital theory and electron density difference. Results show that π-π stacking interactions, hydrogen bonds, CH···π interactions and S-Fe coordination exist in the complexes of NMP-FeCl3 and TH/OCT/TOL/CHA/CHE. The coordination of lone-pair electrons in S atom and empty orbital in Fe atom is the strongest interactions among all complexes, and thus is demonstrated as the predominant desulfurization mechanism of NMP-FeCl3 IL extracting TH from fuel oils.

Template-synthesized nano-Ag2O@HNTs-constructed hierarchical porous-structured PAN composite nanofiber membrane towards selective adsorption desulfurization

As the adsorption technique was concerned, the facile, intact and low-cost separation process of adsorbents was desirable to the prospective feasible application. In present work, the nano-Ag2O particles were encapsulated in the hollow nanostructure of halloysites (HNTs) with the aid of CTAB-stabilized HNTs micelle by the space confinement method, and then the nano-Ag2O@HNTs nanocomposite was assembled in PVP/PAN electrospinning nanofiber membrane (NFM), and finally PVP template was removed through etching method, so as to access the hierarchical-porous structure. The structure and composition of nano-Ag2O@HNTs/PAN NFM were resolved by a series of characterizations. The nano-Ag2O@HNTs/PAN NFM not only was of abundant multi-pore structure with larger specific surface area of 23.484 m2/g and higher pore volume of 0.111 mL/g, but also exhibited excellent mechanical performance, of which the tensile strength and Young's modulus were up to 6.1 MPa and 75.9 MPa, respectively. Thanks to the existence of the exclusive pore structure and nano-Ag2O, the nano-Ag2O@HNTs/PAN NFM showed better adsorption desulfurization performance in the simulated thiophene (TH) oil, of which the breakthrough and saturated adsorption capacity were as high as 35.269 mg/g and 54.481 mg/g, respectively. Ultimately, the adsorption mechanism of TH molecules on the nano-Ag2O@HNTs/PAN NFM could be taken into account the synergistic effect of the porous diffusion, interface adsorption and active site adsorption.

A Novel Electrochemical Strategy for Chloramphenicol Detection in a Water Environment Based on Silver Nanoparticles and Thiophene

As a synthetic broad-spectrum antibiotic, chloramphenicol (CAP) is widely used in the prevention and treatment of bacterial diseases in aquaculture and animal husbandry, which might lead to severe water contamination and thus threaten our health. Herein, a novel electrochemical strategy for CAP detection is proposed that the sensor was successfully constructed based on the hardly mentioned anodic peak (about −0.56 V) by modifying silver nanoparticles (AgNPs) and thiophene (TP) on a glassy carbon electrode (GCE) as synergistic amplification unit with a simple step-by-step electrodeposition technique. Electrochemical methods, scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS) were applied to characterize the as-prepared sensor. The TP/AgNPs/GCE sensor was used for CAP detection by DPV in the concentration range of 100.0 − 1600.0 μM, the limit of detection (LOD) was 33.0 μM, and the sensitivity was 0.290 μA·μM−1·cm−2. In addition, the sensor has the advantages of simple preparation, low cost, good repeatability, stability and anti-interference. It has been used for the detection of CAP in lake water with a recovery of 101.80–104.85%, and the relative standard deviation (RSD) was lower than 1.22%, which confirms that the sensor has good practicability.

High mechanical performance submicron-sized Cu2O-derived necklace-shaped PAN nanofiber composite membrane towards adsorption desulfurization application

The selective adsorption desulfurization technology is considered to be of energy conservation and environment-friendly operation. However, the ongoing development of adsorption desulfurization is greatly restricted by the adsorbents with preferable mechanical properties and sustainable separation efficiency. In this paper, a submicron-sized Cu2O necklace-shaped polyacrylonitrile (PAN) nanofiber composite membrane (Cu2O/PAN NFM) was prepared by electrospinning technology. The structure and mechanical properties of NFM were determined by a series of characterizations. The results showed that the resulting Cu2O/PAN-NFM has a larger total pore volume (0.0802 mL/g), higher tensile strength (5.65 MPa) and lower friction coefficient (0.2571) than those of PAN nanofiber membrane (PAN NFM). The static and dynamic adsorption performances of the Cu2O/PAN NFM were investigated with thiophene(TH) simulated oil. The results showed that the static and dynamic saturated adsorption capacities of the Cu2O/PAN NFM were up to 32.91 mg/g and 4.57 mg/g at 500 mg/L initial concentration, respectively. Besides, the adsorption kinetics and isotherms of TH on the Cu2O/PAN NFM indicated that the TH adsorption data are fitting to Avrami model and Liu isotherm. In addition, the exclusive notable merits of the Cu2O/PAN NFM expressed at the robust mechanical properties and outstanding separation efficiency while keeping the sustainable adsorption capacity after the repeated recycling, which exhibited a promising application towards adsorption desulfurization.