Separations
·
2024
·Vol. 11
·期 11
·327
·
IF 2.5
Yifeng Li,Jingyue Chen,Xiwei Tan,Han Lou,Hongbo Gu
Hexavalent chromium, one of the heavy metal pollutants in water, harms the ecological environment and human health. In this work, an aniline-p-phenylenediamine copolymer has been prepared by chemical oxidative polymerization to remove the hexavalent chromium (Cr(VI)) from wastewater. The results show that when the initial Cr(VI) concentration is 1.5 mg·L−1, the removal percentage (RP%) of Cr(VI) could reach 94.84% after 180 s of treatment. The RP% of Cr(VI) increases with the dosage of copolymers and decreases with an increase in the initial Cr(VI) concentration. Additionally, the RP% of Cr(VI) removal reaches a maximum of 97.70% with a pH value of 1.0. The Cr(VI) removal kinetics of the copolymers follows a pseudo-first-order chemical reaction model. The X-ray photoelectron spectroscopy (XPS) results demonstrate that the Cr(VI) removal mechanism by the aniline-p-phenylenediamine copolymer is a redox reaction. The positive value of ΔH° and negative value of ΔG° affirm that the Cr(VI) removal process by aniline-p-phenylenediamine copolymer is endothermic, thermodynamically achievable, and spontaneous.
研究领域:
环境科学
·
材料科学
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ACTA PHYSICO-CHIMICA SINICA
·
2023
·
IF 10.9
Qing Li,Guangxun Zhang,Yuxia Xu,Yangyang Sun,Huan Pang
Urea electrolysis is critically important for the advancement of sustainable and clean energy conversion technologies, addressing global energy shortages and environmental concerns. The urea oxidation reaction (UOR) poses a significant challenge due to its unfavorable thermodynamics, making it a pivotal step in urea splitting. The 6-electron transfer process of UOR presents a bottleneck due to its sluggish kinetics. Consequently, the development of efficient urea oxidation electrocatalysts and gaining insights into the electronic configuration of the central metal ion are of paramount significance in achieving high-performance urea-based energy conversion technologies. In this study, we report the successful synthesis of hierarchical Ni 2 P nanosheets@nanorods (P-Ni 2 P HNNs) as promising catalysts to enhance UOR efficiency. This catalyst is designed and constructed using a hexamethylenetetramine-hydrolytic coprecipitation-oxidation process and a straightforward phosphorus-substituted method. X-ray absorption fine structure spectroscopy indicates that the presence of P-modified metal centers is responsible for the elevated UOR activity of P-Ni 2 P HNNs, with the electronic structure of Ni n + significantly enhancing Ni―O―O bond coupling for rapid UOR kinetics. Thanks to the highly exposed Ni n + centers and the well-designed architecture, P-Ni 2 P HNNs exhibit superior UOR activity and stability, with a low overpotential of 132 mV at 10 mA∙cm −2 , a small Tafel slope of 33.7 mV∙dec −1 , and sustained durability for 6 h at 10 mA∙cm −2 . Furthermore, a two-electrode cell for overall urea electrolysis is assembled with a P-Ni 2 P HNNs-2/NF anode, yielding a low potential of 1.411 V at 10 mA∙cm −2 and a high current density of 100 mA∙cm −2 at 1.595 V. This study presents an effective and viable approach for designing and synthesizing high-efficiency nickel-based phosphide electrocatalysts, which could pave the way for cost-effective and energy-efficient electrochemical hydrogen production, and advance phosphide research for various energy-related applications. Download: Download high-res image (132KB) Download: Download full-size image
研究领域:
材料科学
·
电化学
·
能源转换技术
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EUROPEAN POLYMER JOURNAL
·
2016
·
IF 3.485
Meiling Chen,Yuncheng Mo,Zesheng Li,Xiankun Lin,Qiang He
Assembling nanoscale building blocks derived from ultrastrong polymer fibers into ordered architectures should offer an effectively alternative way to access high-performance nanocomposites with extremely high strength and heat resistance for advanced applications. Poly( p -phenylenebenzobisoxazole) (PBO) fibers possess outstanding mechanical and thermal properties among the synthetic organic fibers. Here, commercial PBO fibers have been disintegrated into uniform nanofibers with the diameter of ca. 20 nm by a mixed acid treatment, and then served as a polymeric building block to be assembled into layered architectures through layer-by-layer deposition. The resulting (PBO-PBO) 50 films exhibit superior mechanical and thermomechanical properties with the modulus of 3.29 GPa, the toughness of 2.1 MJ m −3 , and the strength of 181.08 MPa. Through employing the poly(vinyl alcohol) (PVA) as a connecting layer in the deposition, the (PBO-PVA) 50 nanocomposite films possess remarkable mechanical properties demonstrated by the modulus of 6.48 GPa, the toughness of 4.6 MJ m −3 , and the strength of 304.34 MPa, due to the synergistic interfacial interaction between the PBO nanofibers and the matrix. In addition, the (PBO-PBO) 50 films possess the thermal stability up to 625 °C and excellent fire retardancy.
研究领域:
材料科学
·
高分子科学
·
纳米技术
·
热机械性能
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Zi-Chen Wang,Xiao-Di Jiang,Yu-Xian Duan,Xu Wang,Zhen-Hua Ge,Jin-Ming Cai,Xiao-Ming Cai,Hong-Lin Tan
Tin selenide exhibits outstanding thermoelectric properties. Among its various forms, multicrystalline SnSe stands out as a more practical choice compared to single-crystal SnSe, owing to its straightforward chemical synthesis process, enhanced processability, and scalability. Herein, we synthesized p-type polycrystalline Sn 1−x Ag X Se bulk materials (x = 0, 0.01, 0.015, 0.02, 0.025, 0.03) using a simple hydrothermal and hot pressing method. Characterization methods such as XRD , Raman and XPS were used to demonstrate the successful doping of Ag + into the SnSe matrix. When the doping concentration reached Sn 0.98 Ag 0.02 Se (x = 0.02), Ag + reached the optimal concentration in the SnSe matrix, causing significant lattice distortion which increased phonon scattering and lowered the thermal conductivity , resulting in Sn 0.98 Ag 0.02 Se achieving ZT max = 1.14. However, when the doping concentration exceeded Sn 0.98 Ag 0.02 Se (x > 0.02), excess silver ions precipitated, partially acting as charge carriers, leading to a significant increase in electrical conductivity , resulting in Sn 0.97 Ag 0.03 Se having an electrical conductivity of 6860 s/m at 773 K. Compared to the pure phase, the electrical conductivity of Sn 0.97 Ag 0.03 Se increased by 259 %, and the ZT value of Sn 0.98 Ag 0.02 Se increased by 178%. This work demonstrates that Ag + is an effective p-type dopant in the SnSe system and indicates that high ZT values in SnSe can be achieved through a simple, low-cost, and environmentally friendly method.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Zhijie Cui,Zhibo Yan,Jie Yin,Wenpin Wang,Mei-E Yue,Zhongcheng Li
Tailoring surface composition and coordinative environment of catalysts in a nano-meter region often influence their chemical performance. It is reported that CoP exhibits a low dissociation ability of H–OH, originating from the poor desorption of intermediate species. Herein, we provide a feasible method to construct P-Fe 2 O 3 -CoP nanosheets through a gas-phase phosphorization process. P doping induces the formation of interfacial structure between Fe 2 O 3 and CoP and the generation of defective structures. The resulting P-Fe 2 O 3 -CoP nanosheets afford high freshwater/seawater oxidation activity (250/270 mV@10 mA/cm 2 ) in 1 mol/L (M) KOH, which is even lower than commercial RuO 2 . Compared with CoP||CoP, P-Fe 2 O 3 ||P-Fe 2 O 3 , and Co 3 O 4 ||Co 3 O 4 , the assembled P-Fe 2 O 3 -CoP||P-Fe 2 O 3 -CoP exhibits the superior water/seawater electrolysis performance with 1.61/1.65 V@10 mA/cm 2 . The synergistic effect of P doping, defective structure, and heterojunction leads to high water oxidation efficiency and water splitting efficiency.
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CHEMOSPHERE
·
2018
·
IF 4.427
Jing Xu,Heng Zhang,Tao Luo,Zizheng Liu,Jun Xia,Xiang Zhang
The effects of co-existing nitrogen species in surface water on the phototransformation of organoarsenical p -arsanilic acid ( p -ASA) have been investigated using a xenon lamp as a simulated solar light source. Significant enhancements of p -ASA phototransformation efficiency were observed in the presence of nitrate and nitrite, increasing with the concentration of these species and pH, whereas ammonia showed no obvious effect. The products, including inorganic arsenic species and organic derivatives, have been analyzed in order to reveal the phototransformation pathways. In the nitrate and nitrite systems, only small proportions of inorganic arsenic species were generated, with the majority of p -ASA being converted into other organoarsenical derivatives through hydroxylation, nitration, and nitrosation. Phototransformation of p -ASA in collected natural surface water was also observed. This work has implications for the phototransformation of p -ASA in nitrogen-contaminated surface water.
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CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Zhenzhen Liu,Mingjie Chen,Yanzhu Guo,Xing Wang,Li Zhang,Jinghui Zhou,Haiming Li,Qingshan Shi
Cationic amphiphilic cellulose copolymers were prepared through grafting hydrophobic poly (p-dioxanone) (PPDO) chains onto hydrophilic quaternized cellulose derivatives (QC) via ring-opening polymerization (ROP) reaction, which was performed in 1-butyl-3-methylimidazolium chloride (BmimCl) and using 4-dimethylaminopyridine (DMAP) or 1,8-diazabicyclo (5.4.0) undec-7-ene (DBU) as catalyst. Their chemical structures and physical properties were confirmed by FT-IR, 1 H-, 13 C-, 2D HSQC-NMR, X-ray diffraction (XRD), and thermal stability (TGA) techniques, while self-assembly behavior was characterized by dynamic light scattering (DLS), transmission electron microscopy (TEM) and fluorescence techniques. Both of the sizes and critical micelle concentration (CMC) values of micelles were decreased with increasing grafting contents of PPDO in the copolymers, which were in the ranges of 110–246 nm and 64–253 μg/mL, respectively. The ζ-potentials of micelles were cationic andranged from 39.1 mV to 45.4 mV. The highest encapsulation efficiencyof paclitaxel (PTX) into the micelles was 61.8% and 92.0% of loaded PTX was continuously released from micelles in phosphate buffered saline medium for 36 h.
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RUSSIAN JOURNAL OF ELECTROCHEMISTRY
·
2022
·Vol. 57
·期 12
·1213-1223
·
IF 1.351
Uddin W.,Nawabi M. Y.,Rehman S. Ur.,Hu G.,Khan J.,Shen X.
Abstract We introduced a novel technique for monitoring the activity of analytes for the first time. The technique is built upon the inhibitory effect caused by the free-radical-scavengers on the pattern of novel Briggs–Rauscher (BR) electrochemical oscillator catalyzed by tetra-aza-macrocyclic complex catalyst ([NiL](ClO 4 ) 2 . The ligand “L” in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. The effect involves a sudden ceasing of oscillation, an inhibition time ( t in ) that directly proportional to the amount of additive ( p -Dimethylaminobenzaldehyde ( p -DMAB)) added, and subsequent restoration of oscillations. Thus, a linear regression curve between concentrations range of 2.7 × 10 –7 mol L –1 to 4.5 × 10 –6 mol L –1 p -DMAB Vs t in was achieved with a correlation coefficient of 0.98. The observed limit of detection (LOD) is 2.7 × 10 –7 mol L –1 while the RSD calculated from 7 measurements of 2.5 × 10 –6 mol L –1 p -DMAB is 1.5%. Factors that influence the determination of p -DMAB were also studied. The mechanistic interpretation of the perturbed oscillation was anticipated from both NF and FCA models. A fleeting elucidation is that the intermediate species (HOO • ) produced during oscillatory reactions and reacted with p ‑DMAB. As a result, the oscillation was temporarily ceased.
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2022
·Vol. 33
·期 6
·1892-1897
·
IF 3.348
Xing Chen,Chenyang Hu,Huidi Xu,Rui Qu,Xiaohong Hu,Jie Yang,Xiaofeng Song
Polyurethane (PU) as a multifunctional material has been produced by various methods. In this work, a series of novel chloric PUs are made from p -toluene sulfonyl isocyanate (TSI) and epichlorohydrin (ECH) via direct salen catalysis under mild temperature. Catalytic efficiency and activity of salen metal complexes are analyzed and evaluated. The salen-cobalt (III) (DNP) exhibits high yield, excellent urethane selectivity, narrow polymer weight distribution in bulk polymerization with the molar ratio of TSI with catalyst changing. And compared to bulk polymerization, salen-cobalt (III) (DNP) can promote the reaction better in solution polymerization and synthesize the product with higher molecular weight. The obtained polymer shows excellent thermal stability, and its thermal degradation starts from 240.8°C. So, it will provide experience for developing functional PU under mild reaction conditions.
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Biosensors-Basel
·
2022
·Vol. 12
·期 10
·813
·
IF 5.743
Chao Hu,Ping Pan,Haiping Huang,Hongtao Liu
Cr-MOF nanoparticles were synthesized by a simple hydrothermal method, and their morphology and structure were characterized by SEM, TEM, and XRD techniques. The Cr-MOF modified glassy carbon electrode (Cr-MOF/GCE) was well constructed and served as an efficient electrochemical sensor for the detection of p-nitrophenol (p-NP). It was found that the Cr-MOF nanoparticles had significant electrocatalytic activity toward the reduction of p-NP. The Cr-MOF-based electrochemical sensor exhibited a low detection limit of 0.7 μM for p-NP in a wide range of 2~500 μM and could maintain excellent detection stability in a series of interfering media. The electrochemical sensor was also practically applied to detect p-NP in a local river and confirmed its validity, showing potential application prospects.Keywords:nanoparticle;modified electrode;electrochemical sensor;electrocatalytic activity;detection limit
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Nano Energy
·
2022
·
IF 19.069
Sijing Liu,Yuewang Yang,Shusheng Chen,Jiongzhi Zheng,Dong Gyu Lee,Dan Li,Jinglei Yang,Baoling Huang
Flexible ionic thermoelectric materials with large thermopowers show great promise for ultrasensitive thermal detection in wearable devices . Here large and tunable p- and n-type thermopowers are reported in stretchable and self-healing ionogels made of a fluorocarbon elastomer poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), an ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) and a salt acting as the thermopower regulator. Particularly, a self-healing n-type ionic thermoelectric material is developed for the first time. The thermopower of the resultant ionogels varies from + 30 mV K −1 to − 21 mV K −1 at 90% relative humidity. Meanwhile, the ionogels exhibit excellent stretchability up to 1700% and appropriate Young’s modulus of around 0.26 MPa. Both the mechanical and thermoelectric properties can self-heal spontaneously after damage. Taking advantage of the large p and n-type thermopowers, the stretchable self-healing ionogels are integrated as a flexible thermoelectric detector with 10 pairs of p- and n-type legs on copper electrodes, showing a total thermopower of 0.25 V K −1 operating with a low temperature difference of 1–2 K.
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MOLECULES
·
2021
·Vol. 26
·期 22
·6849
·
IF 4.412
Yan Fan,Tao Wang,Yinwei Qiu,Yinli Yang,Qiubo Pan,Jun Zheng,Songwei Zeng,Wei Liu,Gang Lou,Liang Chen
Graphene p-n junctions have important applications in the fields of optical interconnection and low–power integrated circuits. Most current research is based on the lateral p-n junction prepared by chemical doping and other methods. Here, we report a new type of pure graphene oxide (pGO) vertical p-n junctions which do not dope any other elements but only controls the oxygen content of GO. The I–V curve of the pGO vertical p–n junction demonstrates a remarkable rectification effect. In addition, the pGO vertical p–n junction shows stability of its rectification characteristic over long-term storage for six months when sealed and stored in a PE bag. Moreover, the pGO vertical p–n junctions have obvious photoelectric response and various rectification effects with different thicknesses and an oxygen content of GO, humidity, and temperature. Hall effect test results show that rGO is an n–type semiconductor; theoretical calculations and research show that GO is generally a p–type semiconductor with a bandgap, thereby forming a p–n junction. Our work provides a method for preparing undoped GO vertical p–n junctions with advantages such as simplicity, convenience, and large–scale industrial preparation. Our work demonstrates great potential for application in electronics and highly sensitive sensors.Keywords:undoped p–n junction;vertical p–n junction;graphene oxide
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