Search

To solve the problem of urban freight demand and build an efficient, practical, intelligent, green, and sustainable new logistics system, this paper considers the application of the subway network to urban freight transportation and studies the location problem of subway transit stations in the urban freight network. According to the differences between different subway stations, the nodal degree, medial centrality, proximity centrality, and regional accessibility are proposed as the evaluation indexes, and the improved fuzzy analytic hierarchy method and entropy weight method are used to calculate the index weight. The TOPSIS evaluation method is used to evaluate the importance of each subway station, and the importance evaluation model of subway stations is constructed. Combined with the distribution location and transportation demand of urban express delivery outlets, a two-tier planning model for the location of subway transfer stations was constructed with total cost and customer satisfaction as the objective functions, and the case studies were carried out by taking Jiangning District, Lishui District, and Gaochun District of Nanjing as the research objects. The results show that Hohai University Focheng West Road, Zhengfang Middle Road, Qunli, and Gaochun can be transformed into subway transfer stations and used as transshipment centers of the urban cargo transportation network. Compared with the original ground transportation network, 52.87% of the ground transportation distance in the optimized transportation network is replaced by subway transportation, and the total cost of logistics transportation is reduced by 8.73%, which verifies the feasibility of subway for urban cargo transportation, reduces logistics transportation costs, and relieves the pressure of ground transportation, which is of great significance for the sustainable development of urban logistics. [ABSTRACT FROM AUTHOR]

Araneose Ti3+ self-doped TiO2/SiO2 nanowires (RTiO2/SiO2) were prepared and anchored onto a polyethersulfone (PES) membrane. Careful characterizations and measurements indicated a covalent grafting of SiO2 onto reduced TiO2 (RTiO2) through Ti–O–Si linkages, acquiring uniformed RTiO2/SiO2 nanowires of almost complete anatase and benign hydrophilicity. The RTiO2/SiO2-based PES membrane showed a significantly enhanced visible light–driven degradation rate of methylene blue (MB) (90.7%), compared with that on bare PES (11.1%) and PES-RTiO2 (59.6%) membranes. The residual MB in filtered water was less than 5% after reusing three times. The normalized permeate flux of the modified membrane was 0.83, and the transmembrane pressure only increased by 0.4 MPa under irradiation of visible light. The improved performance of the PES-RTiO2/SiO2 was attributed to efficient intercept of MB molecular, light harvesting of visible light, and separation of charge carriers on araneose RTiO2/SiO2 nanowires. [ABSTRACT FROM AUTHOR]

Fe-modified perovskite-type NaMgF 3 photocatalysts were synthesized via a microemulsion method followed by calcinations. The as-prepared catalysts were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Brunauer–Emmett–Teller specific surface areas (BET) measurements, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), and Photoluminescence spectroscopy (PL). The photocatalytic activity of as-prepared materials was obtained via degradation of aqueous Rhodamine B. Results demonstrate that the Mg 2+ in NaMgF 3 may be substituted by a low amount of Fe 3+ , forming a finite solid solution NaMg 1-x Fe x F 3 ( x  = 0–0.3), while the perovskite-type framework of NaMgF 3 remains unchanging. Simultaneously, α-Fe 2 O 3 is formed to construct an efficient heterostructure. The Fe-modification inside of the lattice of NaMgF 3 can suppress growth and aggregation of NaMgF 3 crystallion, thus improving the light response and inhibiting the recombination of phtogenerated hole/electron pairs by forming a donor level of impurities and shallow traps in their lattice matrix. α-Fe 2 O 3 formed outside of NaMg 1-x Fe x F 3 can tightly bond to construct an efficient heterostructure between α-Fe 2 O 3 and NaMg 1-x Fe x F 3 , which is also an important factor of optical absorbance improvement and phtogenerated hole/electron pair separation, due to the migration and jumping of electrons or holes between the two semiconductors. The photocatalytic degradation rate of Rhodamine B on the modified catalyst under optimal content of Fe 3+ (10 mol%) reached to 93% within 1 h, and about 7.6 times of the rate constant of that on raw NaMgF 3 was observed. The results show that h + as well as ∙OH play dominant roles of the photodegradation of Rhodamine B. After the 5th photocatalytic experiment, the photocatalytic degradation rate of Rhodamine B retains more than 90% of the original value. [ABSTRACT FROM AUTHOR]

In this work, Chlorella pyrenoidosa was chosen as model microalgae, and several pretreatments, including hydroxyl-peroxide-aided ultrasonic pretreatments and mono-ultrasonication (US), were used to rupture the microalgal cells for extracting cellular inclusion. The disruption efficiency and the energy consumption of each technique were estimated through measuring the amount of released protein from cells and the microscopic images after pretreatment. Results showed that the combined pretreatments obtained a much higher lysis efficiency than did the US (over twofold). However, the concentration of H2O2 used (ranging from 0.1 to 5 mM) failed to influence the lysis efficiency significantly ( P < 0.05). Additionally, the acoustic energy efficiency was increased with the initial cell concentration treated, but the coefficient of utilization of algal biomass was decreased significantly. Therefore, an ideal initial cell concentration (13.4 × 107 cells/mL) was gained in terms of the higher coefficient of utilization of algal biomass. This research suggested that a synergistic technique could be an effective pretreatment for microalgal cell disruption and downstream comprehensive utilization. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Difficult storage of hydrogen peroxide (H 2 O 2), low production of reactive oxygen species (ROS), and inefficient Fe(II)/Fe(III) recycling limit the application of the Fenton-like process. Calcium peroxide (CaO 2) based iron oxychloride (FeOCl) system was developed for solving these deficiencies, and ciprofloxacin (CIP) was effectively degraded within 20 min treatment. 0.33 mmol/L H 2 O 2 and 2.4 mg/L dissolved oxygen (DO) were produced via CaO 2. Quenching experiments and electron paramagnetic resonance results confirmed that hydroxyl radicals (·OH) and superoxide anion (·O 2 −) worked as the main ROS. Density functional theory (DFT) calculations and experimental results suggested that H atoms of H 2 O 2 adsorbed on FeOCl favored the activation of H 2 O 2 into ·OH and DO into ·O 2 −, and electrophilic Cl and O coordination in FeOCl contributed to the cycle of Fe(II)/Fe(III). ·OH and·O 2 − were responsible for CIP degradation, and toxicity assessments demonstrated that the developed system reduced the hazard of treated solution. Clarity of FeOCl/CaO 2 system triple roles, including H 2 O 2 and O 2 production, activation into ROS, and Fe(II)/Fe(III) recycling, facilitates the efficient utilization of O 2 in Fenton-like system. [Display omitted] • In situ H 2 O 2 and O 2 could be continuously produced from CaO 2. • Reactive oxygen species were derived from the activation of H 2 O 2 and O 2 by FeOCl. • H atoms of H 2 O 2 adsorbed on FeOCl favored the generation of reactive oxygen species. • Fe(II)/Fe(III) recycling was efficiently carried out at the solid-liquid interface. [ABSTRACT FROM AUTHOR]

Construction of Z-scheme heterostructure is an effective strategy to enhance the charge carriers' separation. However, successfully achieving this on the defect heterojunction to improve the photocatalytic activity remains challenging. This work successfully obtained sulfur vacancy in the ZnIn 2 S 4 /BiOBr (SZIS/BOB) heterojunction composites with S–O covalent bonding using a hydrothermal method. As a result, they exhibited superior photocatalytic and stability performance. The optimized SZIS/BOB-10 exhibited excellent rhodamine B degradation (95.2%) and chromium (VI) reduction (97.8%) within 100 min under visible light. The enhanced composites with S-vacancies, S–O bond, and internal electric field induced the Z-scheme charge transfer mechanism. We had verified this mechanism based on the surface photovoltage spectra, electron spin response spectra, and density functional theory calculations. This work not only provides valuable insights into designing photocatalysts with a direct Z scheme heterostructure but also delineates a promising strategy for developing efficient photocatalysts to degrade organic pollutants. Schematic illustration of the possible photoelectron generation and transport routes in the SZIS/BOB heterostructure. Also, the photocatalytic reaction mechanism for RhB degradation and Cr(VI) reduction under visible light irradiation. [Display omitted] • Constructing surface defect ZnIn 2 S 4 /BiOBr heterojunction. • The S–O covalent bond was found in the ZnIn 2 S 4 /BiOBr heterojunction interface. • The S–O bond boosting interfacial charge transfer in ZnIn 2 S 4 /BiOBr heterojunction. • ZnIn 2 S 4 /BiOBr exhibited outstanding photocatalytic performance under visible light. [ABSTRACT FROM AUTHOR]

TiO 2 coated on activated carbon (TiO 2 /AC) was synthesized by a facile sol-hydrothermal preparation. The as-prepared TiO 2 /AC was modified by sequential treatment of nitric acid and thionyl chloride, followed by surface attaching of diethylenetriamine. The obtained materials were characterized by transmission electron microscopy, Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, BET adsorption, and their adsorption–photocatalytic reduction activities were evaluated by the removal of aqueous Cr(VI). The results showed that TiO 2 particles were homogeneously deposited on the surface of activated carbon, and diethylenetriamine was grafted covalently onto the surface of TiO 2 /AC through amide linkage. The diethylenetriamine-functionalized TiO 2 /AC (TiO 2 /AC-DETA) exhibits high adsorption capability for Cr(VI) through electrostatic, coordinative and hydrogen bonding interactions. The significant enhancement of photocatalytic activity of TiO 2 /AC-DETA for reduction of Cr(VI) was observed, which was mainly attributed to the enrichment of Cr(VI) onto the surface of AC and successive fast interfacial transfer of Cr(VI) and photogenerated electrons resulted from the intimate contact between AC and TiO 2 through dense heterojunctions by forming of C–O–Ti linkages. [ABSTRACT FROM AUTHOR]

Abstract: A new method to enhance photocatalytic performance of TiO2 by dispersing it onto hydrophilically surface modified carbon nanotubes is reported. The hydrophilically surface functionalized CNTs and as prepared composite CNTs-TiO2 photocatalysts were characterized using FT-IR, XPS, XRD, BET adsorption analysis and TEM. The composite samples were evaluated for their photocatalytic activity toward the degradation of methyl orange in aqueous solution under both UV and visible light irradiation. The results indicated that the hydrophilic functional groups were grafted covalently on the surface of CNTs successfully, and the functionalized CNTs exhibit higher BET specific surface area and aquatic solubility. The improved photocatalytic activity of CNTs-TiO2 was mainly attributed to the high dispersion of TiO2 on CNTs and the intimate contact between TiO2 and CNTs resulting in dense heterojunctions at the interface of TiO2 and CNTs. [Copyright &y& Elsevier]