Diatomite supported highly-dispersed ZnO/Zn-co-embedded ZIF-8 derived porous carbon composites for adsorption desulfurization.

The metal organic framework (MOFs)-derived porous carbon materials with highly dispersed metal active sites were of the exclusive application foreground in many field, such as catalyst, electrochemistry, adsorption desulfurization and so on. However, the loss issue of metal active sites in MOFs frame was indispensable during the high temperature carbonization because of the lower boiling point of many metals, thus fundamentally affecting the atom-scale uniform distribution merit of MOFs-derived porous carbon materials. This work was to provide a novel strategy to address the loss issue of the active metal volatilization in the fabrication of MOFs-derived porous carbon materials. The ZnO nanosheets were pre-grown on the surface of diatomite by using in-situ microwave-assisted preparation, and thereafter the Zn-containing ZIF-8 particles covered the surface of ZnO nanosheets by virtue of the ZnO-induced growth. The results affirmed that the high content Zn-doped porous carbon materials were achieved and the Zn volatilization in MOFs was restrained on account of the occurrence of ZnO on diatomite (DE) surface during the carbonization. The adsorption desulfurization performance of the ZnO/Zn-embedded porous carbon materials/DE (ZnO/Zn/C@DE) was examined by the sulfur-containing compounds in simulated oil. The adsorption desulfurization performance investigation indicated that the ZnO/Zn/C@DE had the optimum adsorption capacities of 45.3 mg/g for benzothiophene and 37.4 mg/g for thiophene. Nonetheless, the competitive adsorption desulfurization finding of toluene in simulated oil showed that the adsorption capacities of ZnO/Zn/C@DE for TH and BT were dramatically descended, suggesting the presence of S-M interaction, wherein S stood for the S atom in a thiophene molecule and their analogs, and M for Zn atoms in porous carbon materials.

A flexible N-doped carbon-nanofiber film reinforced by halloysite nanotubes(HNTs) for adsorptive desulfurization.

This report introduced the facile synthesis of the carbon-nanofiber films reinforced by halloysite nanotubes (HNTs) via electrospinning. The HNTs-reinforced N-doped carbon-nanofiber films (PAN/HNTs-CNFs) possessed the higher strength and toughness while keeping the prospective adsorption capability for different sulfur compounds in oil due to the higher N doping content. The PAN/HNTs-CNFs were produced by firstly electrospinning for the HNTs-filled polyacrylonitrile (PAN) nanofiber films, followed by the high-temperature carbonization for the conversion of the polymer films into the carbon-nanofiber films with the N doping. The characterizations testified that the HNTs were capable of fulfilling the uniform and disordered dispersion in the carbon-nanofibers. For overcoming the toughness of the carbon-nanofiber film, the HNTs filling the obviously improved the mechanical performance of the carbon-nanofiber films by the pulling-out and bridging effect. Due to accessing the lipophilic and acid surface, abundant hierarchical pore structure and highly N-doping content, the PAN/HNTs-CNFs exhibited the remarkable adsorption performances for thiophene, benzothiophene, and dibenzothiophene (46.73 mg S/g, 38.4 mg S/g and 35.03 mg S/g for 800 ppm sulfur model oil), especially being suitable to the adsorption of thiophene. Furthermore, the study on the adsorption kinetics, equilibrium isotherms, and thermodynamics of thiophene over the PAN/HNTs-CNFs were conducted to discuss the adsorption mechanism.

In Situ Study of Structure-Activity Relationship between Structure and Tribological Properties of Bulk Layered Materials by Four-Ball Friction Tester.

Encouragingly, a lot of research studies have demonstrated that two-dimensional (2D) nanosheets applied as an additive in oils show preferable friction-reducing and wear resistance performance. However, the current issue was that an elusive way could be adopted to probe the structure-activity relationship between the structure and tribological properties of bulk layered materials due to the structural evolution during friction testing. In this study, we studied the structure-activity relationship between the structure and tribological properties of bulk layered materials (graphite, h-BN, WS2, and MoS2) by an in situ four-ball friction tester. The morphological and structural changes of the layered materials after in situ four-ball-milling were detected by a series of characterizations. This study revealed the friction-induced nanostructural evolution behaviors of bulk layered materials by a four-ball mode.

Ultrasound-assisted Li+/Na+ co-intercalated exfoliation of graphite into few-layer graphene.

In this work, we developed a novel approach for few-layer graphene by employing Li+/Na+ co-intercalated exfoliation assisted by ultrasound method. The experiments were conducted under the ultrasonic power of 300 W and the frequency of 40 kHz without the participation of any organic solvent. The effect of Li+/Na+ proportion on the exfoliation of graphite was intensively investigated. The structure and morphology of the as-exfoliated graphene nanosheets (UGN) was determined by a series of characterizations. The results showed that the thicknesses of the as-exfoliated graphene nanosheets were about 2.38-2.56 nm (about 7-8 layers) at the optimal Li+/Na+ ratio. The potential application of the as-exfoliated graphene nanosheets as additive in grease was evaluated by four-ball friction tester. The results demonstrated that the antifriction and antiwear performances of the grease with 0.06 wt% graphene were significantly improved by 21.35% and 30.32% relative to pure grease, respectively. The friction mechanism was proposed by detecting the worn surfaces.

Electrospinning fabrication for cloth-like carbon nanofiber films with hierarchical porous structure and their application in deep desulfurization.

A strategy for clean fuel by selective adsorption processing was deemed to be convenient and environmental-friendly in past decades. However, the development of adsorption desulfurization was tremendously subject to the fabrication of high-performance adsorbents with large capacity and high stability. Herein, we designed a novel route to fabricate the cloth-like carbon nanofiber film with a hierarchical porous structure by electrospinning. The structure and properties of the cloth-like carbon nanofiber films were determined by a series of characterizations. Subsequently, the desulfurization performance of the cloth-like carbon nanofiber films was examined by the simulated thiophene (TH) oil. Furthermore, the effect of adsorption conditions on the adsorption capacity was intensively investigated, such as carbonization temperature, initial concentration and desulfurization temperature. The results found that at optimal calcination temperature of 700 °C, the cloth-like carbon nanofiber films possessed the highest micropore volume (Vmic = 0.185 m3/g) and adsorption capacity (qe = 96.6 mg/g) at 800 mg/L initial concentration under the adsorption temperature of 25 °C. The results corroborated that the physical properties of the cloth-like carbon nanofiber films with the surface area of 417.8 m2/g, the total pore volume of 0.187 cm3/g and average pore diameter of 1.36 nm had an important influence on the high adsorption capacity. On this basis, the adsorption experimental data were best fitted to pseudo-second-order kinetic and Langmuir isotherm models. Furthermore, the other highlight of the cloth-like carbon nanofiber films was convenient for the separation from oil, thus achieving the desirable reused performance.

Design and fabrication of in-situ N-doped paper-like carbon nanofiber film for thiophene removal from a liquid model fuel.

The novel nitrogen-doped porous carbon nanofibers film (PAN-CNFs) had been successfully prepared by electrospinning with polyacrylonitrile as carbon precursor after calcination under N2 atmosphere. The structure and physical properties of PAN-CNFs were determined by a series of characterizations. The results showed that the PAN-CNFs-800 have the higher N content (10.02 wt.%), larger surface area (354.327 m2/g) and optional Vmic/VTotal (28.14 %). The adsorption desulphurization was examined by thiophene (TH) simulated oil. The experimental results demonstrated that the PAN-CNFs were the desirable adsorption materials as alternative candidate in present adsorption technique. Furthermore, the pseudo order kinetics and adsorption isotherm of the PAN-CNFs-800 was intensive studied, which exhibited good adsorptive capacity for thiophene (TH) reached 113.33 mg/L according to the Langmuir isotherm model and maintained promising recycling reusing performance. The adsorption mechanism was proposed by these models, which should be attributed to the cooperating effect of the proper pore structure and the π-π complexation interactions.

Ultrasound-Assisted Alkaline Solution Reflux for As-Exfoliated MoS2 Nanosheets.

A facile approach was developed to produce MoS2 nanosheets by ultrasound-assisted reflux exfoliation, which was highly efficient for large-scale production and sustainable for environment. The interlayer force of bulk MoS2 was first exhausted in employing LiOH/NaOH solution by reflux and thereafter quickly exfoliated by ultrasound. The lateral size of the as-prepared MoS2 nanosheets with about 2-9 layers became smaller. Definitely, the average friction coefficient and wear scar diameter of 0.08 wt % MoS2-based oil decreased by about 21.87 and 38.09% relative to the base oil, which displayed better antifriction and antiwear performances.

Hydrothermal-assisted shearing exfoliation for few-layered MoS2 nanosheets.

The exfoliation of bulk MoS2 into few layers has attracted considerable attention as 2D nanomaterials in the past decade. We developed a facile approach for producing MoS2 nanosheets by hydrothermal-assisted shearing exfoliation based on organic-free strategy. This original exfoliation was highly efficient for large-scale production and sustainable for the environment. The thickness of the as-exfoliated MoS2 nanosheets was about 4-6 layers, and the lateral size became smaller from hydrothermal processing to shearing. The hydrothermal processing with the participation of ammonium carbonate played an important role in hydrothermal-assisted shearing exfoliation. As a prospective application, the antifriction performance of the as-exfoliated MoS2 nanosheets in oil was evaluated using a ball-on-ball mode. Evidently, the average friction coefficient and wear scar diameter of 0.08 wt% MoS2-based oil dropped to about 20.66% and 47.27% relative to those of the base oil, which exhibited an excellent antifriction and antiwear ability.

Growth of MoS2 Nanotubes Templated by Halloysite Nanotubes for the Reduction of Friction in Oil.

One-dimensional MoS2 nanotubes with the specific surface area of 89.34 m2/g and the average pore size of 2.52 nm were successfully synthesized by the thermolytical approach assisted by halloysite nanotubes. The tribological properties of MoS2 nanotubes with good dispersion in oil were tested with a four-ball wear tester. The tribological testing results indicated that the average friction coefficient and the average wear scar diameter of the 0.08 wt % MoS2-based oil at 25 °C decreased about 39.2 and 35.0%, respectively, compared to those of the 150 SN base oil, indicating that the as-prepared MoS2 nanotubes as a lubricating additive can enhance the tribological performances. Finally, the lubrication mechanism of MoS2 nanotubes was put forward.

Study on adsorption of rhodamine B onto Beta zeolites by tuning SiO2/Al2O3 ratio.

The exploration of the relationship between zeolite composition and adsorption performance favored to facilitate its better application in removal of the hazardous substances from water. The adsorption capacity of rhodamine B (RB) onto Beta zeolite from aqueous solution was reported. The relationship between SiO2/Al2O3 ratio and adsorption capacity of Beta zeolite for RB was explored. The structure and physical properties of Beta zeolites with various SiO2/Al2O3 ratios were determined by XRD, FTIR, TEM, BET, UV-vis and so on characterizations. The adsorption behavior of rhodamine B onto Beta zeolite matched to Langmuir adsorption isotherm and more suitable description for the adsorption kinetics was a pseudo-second-order reaction model. The maximum adsorption capacity of the as-prepared Beta zeolite with SiO2/Al2O3 = 18.4 was up to 27.97mg/g.

Therapeutic Observation of Acupuncture at Baihui (GV20) in Improving Executive Dysfunction After Cerebral Stroke / 上海针灸杂志

Objective To observe the therapeutic efficacy of acupuncture at Baihui (GV20) in treating post-stroke executive dysfunction.Method Fifty-six eligible patients with post-stroke executive dysfunction were randomized into a treatment group (30 cases) and a control group (26 cases). The treatment group was intervened by acupuncture at Baihui and the control group was intervened by ordinary acupuncture. Before and after the intervention, the Behavioral Assessment of the Dysexecutive Syndrome (BADS) and Trail Making Test (TMT) were adopted to evaluate the executive function, and Modified Barthel Index (MBI) was used to estimate the activities of daily living (ADL).Result Before the intervention, there were no significant differences in comparing the BADS, TMT and MBI scores between the two groups (P>0.05); after the treatment, each scale was improved significantly in both groups (P<0.05). The scores of Rule Shift Cards Test (RSCT), Key Search Test (KST), Temporal Judgment Test (TJT), Zoo Map Test (ZMT) and total point of BADS, TMT-A and MBI scores in the treatment group were superior to those in the control group (P<0.05).Conclusion Acupuncture at Baihui works effectively in improving the executive function of cerebral stroke patients.

Therapeutic Observation of Acupuncture at Baihui (GV20) in Improving Executive Dysfunction After Cerebral Stroke / 上海针灸杂志

Objective To observe the therapeutic efficacy of acupuncture at Baihui (GV20) in treating post-stroke executive dysfunction.Method Fifty-six eligible patients with post-stroke executive dysfunction were randomized into a treatment group (30 cases) and a control group (26 cases). The treatment group was intervened by acupuncture at Baihui and the control group was intervened by ordinary acupuncture. Before and after the intervention, the Behavioral Assessment of the Dysexecutive Syndrome (BADS) and Trail Making Test (TMT) were adopted to evaluate the executive function, and Modified Barthel Index (MBI) was used to estimate the activities of daily living (ADL).Result Before the intervention, there were no significant differences in comparing the BADS, TMT and MBI scores between the two groups (P>0.05); after the treatment, each scale was improved significantly in both groups (P<0.05). The scores of Rule Shift Cards Test (RSCT), Key Search Test (KST), Temporal Judgment Test (TJT), Zoo Map Test (ZMT) and total point of BADS, TMT-A and MBI scores in the treatment group were superior to those in the control group (P<0.05).Conclusion Acupuncture at Baihui works effectively in improving the executive function of cerebral stroke patients.

Preparation and High Permeance of SiO2-Modified Substrate Supported ZSM-5 Membrane by Pre-Seeding and Secondary Nucleation.

SiO2-modified substrate supported compact ZSM-5 membranes with high permeance were prepared using the secondary nucleation method. The synthesis mixture had a molar composition of 10Na2O:84SiO2: 100NaCI:5TPABr:3500H2O. In order to obtain high permeance, a SiO2 meso- porous top layer was added to the macroporous substrate in this study. The SEM images of the seed layer indicate that about 400-500 nm round shaped seeds consisting of 60 nm zeolites fully covered the modifying substrate. The XRD patterns of the zeolite membranes show the purity of the ZSM-5 crystal phase, and reveal the formation of a random orientation on the SiO2-modified substrate. The SEM images of the zeolite membranes indicate that the membranes consist of highly intergrown crystals, with a maximum thickness of about 30 µm. The results of gas permeability studies indicate that the SiO2-modified substrate supported ZSM-5 membranes show good permeance, with the maximum H2permeance achieved being 12.5 x 10⁻7 mol s⁻¹ m⁻² Pa⁻¹. The maximum H2/N2 and H2/CO permselectivities were 4.01 and 4.37 respectively, which are higher than those of the corresponding Knudsen diffusion. The method used resulted in high permeance, while keeping the sustainable permselectivity, and is therefore desirable for practical applications.

Preparation and photoelectrocatalytic performance of N-doped TiO2/NaY zeolite membrane composite electrode material.

A novel composite electrode material based on a N-doped TiO2-loaded NaY zeolite membrane (N-doped TiO2/NaY zeolite membrane) for photoelectrocatalysis was presented. X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible (UV-vis) and X-ray photoelectron spectroscopy (XPS) characterization techniques were used to analyze the structure of the N-doped TiO2/NaY zeolite membrane. The XRD and SEM results verified that the N-doped TiO2 nanoparticles with the size of ca. 20 nm have been successfully loaded on the porous stainless steel-supported NaY zeolite membrane. The UV-vis result showed that the N-doped TiO2/NaY zeolite membrane exhibited a more obvious red-shift than that of N-TiO2 nanoparticles. The XPS characterization revealed that the doping of N element into TiO2 was successfully achieved. The photoelectrocatalysis performance of the N-doped TiO2/NaY zeolite membrane composite electrode material was evaluated by phenol removal and also the effects of reaction conditions on the catalytic performance were investigated. Owing to exhibiting an excellent catalytic activity and good recycling stability, the N-doped TiO2/NaY zeolite membrane composite electrode material was of promising application for photoelectrocatalysis in wastewater treatment.

Preparation of N-doped ZnO-loaded halloysite nanotubes catalysts with high solar-light photocatalytic activity.

N-doped ZnO nanoparticles were successfully assembled into hollow halloysite nanotubes (HNTs) by using the impregnation method. The catalysts based on N-doped ZnO-loaded HNTs nanocomposites (N-doped ZnO/HNTs) were characterized by X-ray diffraction (XRD), transmission electron microscopy-energy dispersive X-ray (TEM-EDX), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), UV-vis and Fourier transform infrared spectroscopy (FT-IR) techniques. The XRD pattern showed ZnO nanoparticles with hexagonal structure loaded on HNTs. The TEM-EDX analysis indicated ZnO particles with the crystal size of ca.10 nm scattered in hollow structure of HNTs, and furthermore the concentration of N atom in nanocomposites was up to 2.31%. The SEM-EDX verified most of N-ZnO nanoparticles existing in hollow nanotubes of HNTs. Besides containing an obvious ultraviolet absorbance band, the UV-vis spectra of the N-doped ZnO/HNTs catalysts showed an available visible absorbance band by comparing to HNTs and non-doped ZnO/HNTs. The photocatalytic activity of the N-doped ZnO/HNTs catalysts was evaluated by the degradation of methyl orange (MO) solution with the concentration of 20 mg/L under the simulated solar-light irradiation. The result showed that the N-doped ZnO/HNTs catalyst exhibited a desirable solar-light photocatalytic activity.