查找使用阿拉丁产品的科研文献

Synthesis of recyclable 3D LC/h-ZIF-8 by Zn(Ⅱ) containing wastewater for photocatalytic degradation of mixed-dye under UV-Vis irradiation

Xiaofeng Huang,Qiulin Deng,Huiwei Liao,Hongquan Deng,Jinlong Jiang,Lixiong Zhang,Xinjun Yao

The treatment process of metal plating wastewater in industry usually exists excessive consumption of chemicals, coproduction of sludge and complex reuse of metal. At present, some available technologies have been designed for effective removal of specific metal ions rather than entire metals ions in effluents. Herein, a novel strategy of treating waste with waste is proposed that using metal plating wastewater containing Zn(Ⅱ) to prepare 3D Luffa cylindrical (LC) / heterogeneous ZIFs (h-ZIF-8) composite (LC/h-ZIF-8) for photocatalytic degradation of organic pollutants (Nitrofurazone (NFZ), Methylene blue (MB), Rhodamine B (RhB) and Congo red (CR)) and mixed-dye wastewater. The strategy realized the efficient treatment of electroplating wastewater, expediently reuse of metal ions and removal of organic contaminants . Moreover, investigations of cycling performance indicated the photocatalytic stability and easy separation from water. Furthermore, the spectroscopy and electrochemical are employed to elaborate possible degradation mechanisms, expounding the LC/h-ZIF-8 possess lower recombination rates of carriers and transfer resistance of electron compared with ZIF-8. Therefore, the work proposes a new strategy for the efficient treatment of metal wastewater and achieves the combination of resource recovery and wastewater treatment with the advantages of simple operation and mild conditions.

An efficient multifunctional catalyst for one-pot synthesis of methyl isobutyl ketone: Phosphor-doped h-BN with adjustable acid-base property as support

Baining Lin,Fan Xu,Yingjie Hu,Xuhong Du,Yingping Zou,Huasheng Xie,Kang Wang,Yonghua Zhou

Developing multifunctional catalyst for cascade reactions such as one-pot synthesis of methyl isobutyl ketone (MIBK) from acetone and hydrogen is critical for practical applications. Here, we adjusted the acid-base property by doping phosphor into h-BN and used it as support for Pd. Experiments and characterizations indicated that the phosphor-doped h-BN could catalyze the aldol condensation and dehydration by modulating the ratio of BNH 2 , N 2 P=O and N 3 P-OH groups thereon. An acetone conversion of 58.24% and MIBK selectivity of 68.39% were achieved over Pd/BN( H )P-E-0.07, providing a new avenue for metal-free materials utilized in the cascade reactions.

A non-metal Acen-H catalyst for the chemical fixation of CO2 into cyclic carbonates under solvent- and halide-free mild reaction conditions

Zhongxiao Yue,Manoj Pudukudy,Shiyu Chen,Yi Liu,Wenbo Zhao,Junya Wang,Shaoyun Shan,Qingming Jia

A metal-free Acen-H catalyst was effectively synthesized by a single step reflux method and successfully tested for the cycloaddition of CO 2 with epoxides to synthesize cyclic carbonates. The Acen-H catalyst exhibited high activity and selectivity for the cycloaddition reaction in the absence of co-catalysts (halides) and solvents at mild reaction conditions of a reaction temperature of 110 °C and a reaction pressure of 1 MPa. Under the optimized reaction conditions, some of the epoxides were successfully converted into corresponding cyclic carbonates with a highest yield of ∼98.5%. The composition and structure of the homogeneous catalyst was then systematically evaluated and the reaction kinetics and a plausible reaction mechanism for the cycloaddition of CO 2 with epoxides were proposed. The density functional theory (DFT) calculation provided a corroborated elucidation for the proposed mechanism. The catalytic activity of the Acen-H catalyst was found to be originated from the active hydrogen bond donors (-O-H, =N---H) and imino groups present (-N=) in it, which played a synergistic role in the adsorption and activation of reactants as confirmed by the DFT studies. The structural characteristics of the catalyst was found to be crucial for the cycloaddition of CO 2 with epoxides.

The relation of interface electron transfer and PMS activation by the H-bonding interaction between composite metal and MCM-48 during sulfamethazine ozonation

Shangyi Li,Jun Huang,Xukai Li,Laisheng Li

Co-Ce as the dominant active sites immobilized MCM-48 (Co-Ce/MCM-48) was fabricated via H-bonding by the hydrothermal and incipient wetness co-impregnation method. The incorporation of Co-Ce/MCM-48 (67.2%) provided higher mineralization of sulfamethazine (SMT) than Co/MCM-48 (62.2%) and Ce/MCM-48 (39.4%) in O 3 /peroxymonosulfate (O 3 /PMS) system at 90 min reaction time. The catalytic efficiency could be further improved owing to enhanced PMS decomposition rate when initial pH increased to 9.4. The electron transfer capacity in Co-Ce/MCM-48/O 3 /PMS was improved according to in-situ electrochemical tests. In situ-Raman characterization implied that PMS was bonded to the Co⋯HO-Si-O-Si-OH⋯Ce to generate the Ce-OH⋯HSO 5 − and Co-OH⋯HSO 5 − complexes, which was decomposed by O 3 and one-electron transfer reaction into reactive oxygen species (ROSs). LC-MS analysis indicated that the breakage of N-S bond, SO 2 extrusion and -CH 3 oxidation on rings were the major degradation pathway during SMT degradation. To uncover the relationship of interface electron transfer with Co-Ce/MCM-48 and PMS activation by O 3 , electron paramagnetic resonance (EPR) spectra was recorded to investigate the variation of ROSs in different processes. Simultaneous PMS reduction and oxidation over the solid-liquid-gas interface occurred for the generation of free and non-free radicals in Co-Ce/MCM-48/O 3 /PMS process.

Effect of different ash/organics and C/H/O ratios on characteristics and reaction mechanisms of sludge microwave pyrolysis to generate bio-fuels

Juan Luo,Junhao Lin,Rui Ma,Xing Chen,Shichang Sun,Peixin Zhang,Xiangli Liu

To study the effects of different ash/organics and C/H/O ratios on bio-fuel characteristics and energy efficiency, four kinds of sludge with different properties were used for microwave pyrolysis (800 °C). Moreover, the microwave pyrolysis reaction mechanisms of different sludge were also explored. The results showed that high-ash sludge could accelerate the frequency of polar molecule rotation in the microwave field due to the presence of oxides with dielectric properties in ash, thereby achieving faster heating rates and higher temperatures. However, compared with high-organic sludge, high-ash sludge exhibited lower bio-gas yield and higher bio-char yield. As the H/C ratio increased from 0.127 to 0.148, the bio-gas yield increased from 15.41% to 40.01%, and the content of H 2 in bio-gas and aliphatics in bio-oil increased to 36.69 vol% and 26.54 wt%, respectively. When the O/C ratio was reduced to 1.31, the content of CO and oxygenated compound in bio-oil increased to 31.25 vol% and 40.04 wt%, which lowered the quality of the bio-oil. Those consequences also determined that a mixture of sludge with different ash/organic ratios could be pyrolyzed to obtain high-quality bio-fuels and high energy efficiency. Differences in C/H/O ratios in the mixed sludge greatly affected the microwave pyrolysis heating process, which affected the pyrolysis reactions and the quality of the bio-fuels. Therefore, this study provides a theoretical basis to elevate the quality of bio-fuels and reduce microwave pyrolysis costs.

Highly Efficient Purification of Multicomponent Wastewater by Electrospinning Kidney-Bean-Skin-like Porous H-PPAN/rGO-g-PAO@Ag+/Ag Composite Nanofibrous Membranes

Na Han,Weijing Wang,Xingshuai Lv,Wenxin Zhang,Chao Yang,Menglu Wang,Xiaohui Kou,Wei Li,Ying Dai,Xingxiang Zhang

Due to the complexity of harmful wastewater components, environmental and multifunctional materials are required for sewage purification. In this paper, a novel kidney-bean-skin-like hydrophilic porous polyacrylonitrile/reduced graphene oxide-g-poly(amidoxime)-loaded Ag+ (H-PPAN/rGO-g-PAO@Ag+/Ag) composite nanofiber membrane was fabricated by combining electrospinning and hydrolysis methods. The spinning solution was pumped at a rate of 0.4 mL/h with the voltage set at a constant value of 23 kV. Then, some of the −CN groups switched to hydrophilic −COOH groups via a hydrolysis method, which acts as a linker of GO-g-PAN, Ag+, and the polyacrylonitrile (PAN) matrix. A further step of chelation and thermal treatment were used for generating Schottky junctions between rGO-g-PAO@Ag+ and Ag. After five-cycle tests, it exhibited outstanding mechanical properties ensuring the filtration and purification performance of the H-PPAN/rGO-g-PAO@Ag+/Ag composite nanofiber membrane (i.e., the tensile strength was still 7.21 MPa, and the elongation was 61.53%) for simulated wastewater. The methods of thermal treatment and high-pressure Hg lamp irradiation promoted the reduction of GO to rGO and Ag+ to Ag particles, which endows the final product H-PPAN/rGO-g-PAO@Ag+/Ag with excellent photocatalytic and bactericidal properties. Its catalytic efficiency for dyes benzoic acid (BA), Rhodamine B (RhB), methylene blue (MB), and methyl orange (MO) was up to 99.8, 98, 95, and 91%. The antibacterial rate was 100% against Escherichia coli and 99% against Staphylococcus aureus. More importantly, the photocatalytic and antibacterial PAN-based nanofiber membrane can be simply scaled up, which provides the membrane with great potential in highly efficient wastewater treatment and augmenting water supply.

Convenient Synthesis of 3D Fluffy PtPd Nanocorals Loaded on 2D h-BN Supports as Highly Efficient and Stable Electrocatalysts for Alcohol Oxidation Reaction

Hua Zhang,Linlin Xu,Yue Tian,Anxin Jiao,Shuang Li,Xiangdong Liu,Ming Chen,Feng Chen

Fuel cells hold great promise for clean and sustainable energy, whereas their widespread commercialization strongly depends on the development of highly efficient and stable electrocatalysts. Herein, three-dimensional fluffy PtPd nanocorals (NCs) loaded on two-dimensional (2D) hexagonal boron nitride (h-BN) supports were successfully achieved by a simple one-step strategy based on ultraviolet (UV) laser-excited photochemical reaction. As for alcohol oxidation reaction, the h-BN/PtPd NCs with unique nanoporous surface provide more enhanced electrocatalytic performances than many previous nanocatalysts, owing to abundant active sites and plentiful charge-transfer channels formed on high electrode–electrolyte contact area. Especially, the mass activity of h-BN/PtPd NCs is about 962.8 mA mgPtPd–1 in methanol oxidation reaction in alkaline solution, which can be maintained at ∼274.9 mA mgPtPd–1 (28.6% of the initial one) even after a 5 × 104 s durability test. The present work not only offers an advanced electrocatalyst for long-term fuel cells but also provides a versatile route for construction of complex metallic nanocomposites on 2D supports, holding great potential for diverse energy-related applications.

Effect of ${\rm H}_{2}$ on the Formation Mechanism and Magnetic Properties of FePt Nanocrystals

B. R. Bian,W. X. Xia,J. Du,J. Zhang,J. P. Liu,Z. H. Guo,A. R. Yan

Efficient electrocatalytic degradation of tigecycline by copper foam-supported Pd-ZnS dual nanoparticle structures: A study of H* reduction and mechanism of action

Ruoyi Li,Muchen Lu,Jiaqi Yu,Jian Zhang,Jia Li,Xinyan Wang

Tigecycline (TGC), a third-generation, broad-spectrum, potent antimicrobial drug based on a tetracycline structure, may pose potential hazards to ecosystems and human health due to its difficulty in natural degradation in the environment. However, the environmental degradation behavior of TGC has not been fully investigated, so it is still a major challenge to rationally design efficient, stable, environmentally friendly and cost-effective electrocatalysts for TGC degradation. In this study, Pd-ZnS NPs/CF composite electrode anchored on copper foam (CF) was synthesized by simple ultrasonic method and two-step electrodeposition. The degradation efficiency of TGC at the Pd-ZnS NPs/CF composite electrode was as high as 88.75 % within 30 min under neutral conditions, and the energy consumption was only 0.11 kWh/m³ . In addition, the overall Pd 2+ contribution was as low as 0.00005 M after the introduction of inexpensive ZnS. The Pd-ZnS NPs/CF composite electrode exhibited excellent electrocatalytic activity and degradation of antibiotics under different aqueous environmental conditions. Suitable for degradation of a wide range of antibiotics with excellent cyclic stability. The TGC degradation rate was stabilized above 85.40 % after 240 min of continuous operation in a continuous flow reactor, and the composite electrode prepared once can be used for a long time. It highlights the broad application prospects of the composite electrode in the field of water treatment technology and the significant advantages of high efficiency, low energy consumption and stable long-term operation. In this study, the mechanism of action of ·OH and H* with TGC is also deeply investigated, and the dynamics of TGC degradation intermediates are probed using two-dimensional correlation spectroscopy (2DCOS) and density-functional theory (DFT) calculations. Finally, the ecotoxicity of Pd-ZnS NPs/CF composite electrodes is investigated, which provides a simple and feasible idea for the preparation of efficiently degraded antibiotic cathodes.

Interfacial high-valence Ni(IV)-enabled C-H activation for photoelectrochemical C-C bond cleavage of lignin to exclusively produce aromatic carboxylic acids

Pei-dong Wu,Lanyun Li,Hu Li,Zhen Fang

Sustainable upgrading of biomass to high-value chemicals is greatly dependent on catalytic C-C/C-O bond cleavage of high selectivity. Here, an oxidation-enhanced photoelectrochemical protocol was developed to be capable of breaking different types of C-C bonds for efficiently producing aromatic carboxylic acids (85.0–99.8% yields) from lignin. Ni local electronic state of the prepared F-Fe 2 O 3 -Co:NiO x H y with excellent durability could be modulated, and high-valence Ni(Ⅳ) reactive species played a key role in the oxidative C-C bond scission of various lignin models. In-situ characterization and control experiments indicated that photocatalytic radical and electrocatalytic interface facilitated C-H/O-H delocalization, contributing significantly to the enhanced oxidation process. In addition, quantum calculations elaborated that photo-excited holes and Ni(Ⅳ) are key reactive species for enhancive electrocatalytic cleavage of different C-C bonds in lignin to exclusively furnish aromatic carboxylic acids. This research provides a renewable funnel strategy for using solar energy to produce high-value mono-functional products from biomass.

Construction of relay reaction system by Co@S-1 and In-Ce/H-Beta for selective catalytic reduction of nitrogen oxides with methane

Mingkang Zhang,Jingwei Wu,Haolin Yang,Xiaohan Wang,Zebao Rui,Junfei Chen

Selective catalytic reduction of nitrogen oxides with methane (CH4-SCR) is an effective way to simultaneously eliminate NOx and CH4 emissions. Development of efficient CH4-SCR reaction system with high NOx reduction activity and selectivity is highly desirable for its commercial application. Herein, a two-part relay reaction system, including sequentially Co@S-1 and In-Ce/H-Beta catalysts, is designed for boosting CH4-SCR. In this system, the Co@S-1 with high redox ability boosts NO oxidation to NO2 and generates key intermediate CH3NO2 that can partially be in situ oxidized and the excessive can migrate to In-Ce/H-Beta. Meanwhile, the inner synergistic effect between InO+ and CeO2 species on In-Ce/H-Beta not only exhibits fair CH4-SCR performance, also facilitates the formation of NO- 3 species to react with the migrated CH3NO2 from Co@S-1. Benefiting from the combination between outer active sites synergy and inner active sites synergy, the simultaneous efficient conversion of NOx (T50 = 380 ℃) and CH4 (T50 = 425 ℃) with well durability is achieved.

Mixed matrix composite membranes comprising nanocage-like hollow ZIF-71(h) polyhedral nanocrystals in poly(ether-block-amide) membranes for phenol/water separation

Zhongming Zhang,Enfang Gou,Zhiying Zhao,Rui Wu,Rui Fang,Weipeng Guo,Jie Yao

Organophilic pervaporation (PV) mixed matrix membranes (MMMs) have enormous potential for organic wastewater treatment due to their environmental friendliness and high efficiency. However, developing a high-flux PV membrane remains challenging. In this work, the nanocage-like hollow ZIF-71(h) (HZIF-71(h)) polyhedral nanocrystals were synthesized by heteroepitaxial growth of a ZIF-71(h) shell and successive excavation of a ZIF-67 core. The resultant HZIF-71(h) nanocrystals were blended with poly (ether block amide) (PEBA) matrix to fabricate MMMs for phenol/water separation. Results from several characterization techniques confirmed the successful preparation and formation mechanism of HZIF-71(h). Further, a series of experiments were conducted using the composite membranes to explore the impact of filler type, filler loading, operating temperature, and feed concentration on the separation performance. The incorporation of ZIFs facilitated phenol permeation while limited water transport, thereby resulting in increased separation factor. Notably, the HZIF-71(h)/PEBA-21 MMM exhibits a higher phenol flux in comparison to ZIF-71/PEBA-21 and ZIF-67/PEBA-21 MMMs, indicating the importance of the low-resistance hollow structure. The HZIF-71(h)/PEBA-21 MMM exhibits outstanding pervaporation performance with a separation factor of 15.86 and a phenol flux of 17.32 g·m −2 ·h −1 , respectively, displaying an improvement of 41.2 % and 6.4 % compared to the PEBA/PVDF membrane. Furthermore, this composite membrane demonstrated outstanding durability during continuous testing for 84 h, implying a promising potential for phenol separation.