MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yi Tian,Yunlong Yue
To improve the photoluminescence (PL) and increase photostability of carbon dots (CDs), phosphorus doped CDs with bright green emitting were prepared using (NH 4 ) 2 HPO 4 and m-phenylenediamine (MPD), and terephthalic acid (TA) via a solvothermal synthesis. Compared to undoped CDs (M−CDs), the PL efficiency of P-doped sample (M−6 %P-CDs) created using optimized conditions was improved from 55.1 to 73.9 %. These bright CDs were incorporated in films to test the stability, in which the photostability in liquid and polymer films were improved by 6 and 37 %, respectively. Namely, it is found that P affected the functional groups of on the surface and inside CDs. Phosphorus promoted the dehydration condensation reaction of precursors, increased the structural defects of the CDs, separated the sp 2 structural domains, and retained more oxygen-containing functional groups. In the case of o-phenylenediamine (OPD) instead of MPD, the PL efficiency of P-doped CDs was decreased. This is ascribed to P impeding the polymerization process of OPD. These CDs were used for pH and Cr(VI) ion sensors. P-doping improved the sensitivity of CDs to pH and Cr(VI). The pKa value of sample M−6 %P-CDs was 8.32 which was much lower compared with undoped one (∼1.97). Moreover, P-doped CDs revealed significantly enhanced sensitivity response to Cr(VI). The detection range and detection limit of M−6 %P-CDs for Cr(VI) was 1–130 μM and 0.59 μM, respectively. These results are crucial for the preparation and applications of CDs.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2014
·Vol. 15
·期 7
·1364-1368
·
IF 1.113
Chen Zaina,Feng Xiaoxiao,Han Danmin,Wang Liting,Cao Weipen,Shao Linjun
Porous polyacrylonitrile (PAN) fiber mat was prepared by electrospinning PAN in N,N -dimethylformide solution with poly(methyl methacrylate) (PMMA) as pore-forming agent. Then, the porous PAN fiber mat was chemical modified by the tetraethylenepentamine to acquire aminated porous polyacrylonitrile (APPAN) fiber mat. Common aminated PAN fiber mat was also prepared for comparison. The surface morphologies of the APPAN and PAN fiber mat were characterized by scanning electron microscopy (SEM) and the corresponding specific surface areas were also measured. FT-IR/ATR spectra of the APPAN and PAN fiber mat were recorded for analysis of the surface chemical structures. The Cr(VI) absorption results demonstrated that the porous structure in the fiber could obviously increase the absorption capacity of the fiber mat.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 64
·59292-59298
·
IF 3.289
Jianqiao Zhang,Huan Chen,Zi Chen,Jiaojie He,Wenxin Shi,Dongmei Liu,Huizhong Chi,Fuyi Cui,Wei Wang
A high-performance, cost-effective and spongeous adsorbent was rationally designed for Cr(VI) removal from aqueous solution based on PPy modified natural quasi two-dimensional (2D) structures. Core of corncobs, a kind of agricultural waste composed of quasi 2D sub-micro sheets, has a unique macroporous spongeous microstructure. In consideration of the unique chemical structure of polypyrrole (PPy) and microstructure of the natural sponge, we constructed the microstructured spongeous adsorbents. The PPy active layer provided reactive sizes to detoxifies Cr(VI) ions by ion-exchange. While the spongeous microstructure provided by the microsheets could enhance the adsorption performance by increasing active areas and facilitating the access of pollutants inside the adsorbents. Compared with artificial nano-powder adsorbents, CC–PPy displayed larger advantage in separation process and fabrication/operation cost. Compared with other bulk-style PPy composites, the adsorption capacity of CC–PPy was several times higher. In addition, the regeneration and stability of CC–PPy was outstanding with no loss in the adsorption to Cr(VI) even after 3 adsorption–desorption cycles. The present development provides a solution to design highly efficient and cost-effective water treatment agents.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 10
·3645
·
IF 3.748
Minmin Zou,Ming Dong,Mingliang Luo,Hexin Zhu,Tian Zhao
Hierarchically porous MIL-101(Cr) (H-MIL-101(Cr)) with meso/macro-pores was directly prepared via nanofusion progress by using butyric acid as a modulating agent. In the methyl orange (MO) adsorption experiments, H-MIL-101(Cr) showed a high adsorption capability of 369.8 mg g−1, which was 1.52-fold greater than that of pristine MIL-101(Cr) (P-MIL-101(Cr)). While in the oxidation reaction of indene and 1-dodecene tests, H-MIL-101(Cr) presented much higher catalytic efficiency, with turnover frequency (TOF) values of 0.7242 mmol g−1min−1and 0.1492 mmol g−1min−1, respectively, which were 28% and 34% greater than that in the case of P-MIL-101(Cr). Thus, compared with P-MIL-101(Cr), H-MIL-101(Cr) exhibited better removal efficiency and higher levels of activity in the oxidation reactions of indene and 1-dodecene. The unique structure of H-MIL-101(Cr) also contributed to its superior performance in these processes.Keywords:hierarchically porous;MIL-101(Cr);butyric acid;MO adsorption;catalysis
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Ye Zhaochun,Yao JiaCheng,Zheng Wen,Yuan Wenhui,Guan Jianyu,Li Li,Xiao Hong
Octafluoropropane (C 3 F 8 ) is a kind of super greenhouse gas, and the low concentration of octafluoropropane makes it difficult to be adsorbed and removed. In this study, a series of Co-doped MOFs (Co x Cr-MIL-101) have been successfully synthesized using a hydrothermal method without the addition of strong acids such as HF. The structural properties of the prepared Co x Cr-MIL-101 are characterized using SEM, XRD, nitrogen adsorption desorption test, etc. The adsorption properties of C 3 F 8 are measured by single-component isothermal adsorption experiments and fixed bed adsorption breakthrough experiments. The adsorption mechanism was investigated via the adsorption theory models. The results show that the introduction of cobalt ions can effectively improve the adsorption capacity of MIL-101, among which the Co 0.2 Cr-MIL-101 exhibits the best adsorption performance. The C 3 F 8 equilibrium adsorption capacity reaches 0.077 mmol/g at 298 K and 180 Pa, which is 3.03 times that of the pristine MIL-101 and the dynamic adsorption capacity is 20.710 mmol/g (298 K, 1.2 L/min), which is 9.37 times that of the pristine MIL-101. Inspiringly, the IAST separation selectivity of C 3 F 8 /N 2 at 100 kPa is up to 146.7, which is 14.3 times that of the pristine MIL-101. More importantly, the co-modified adsorbent showed better thermal stability and cyclic stability. In addition, Co 0.2 Cr-MIL-101 fits the Freundlich isothermal adsorption model, and the adsorption mechanism analysis shows that the high adsorption capacity of Co 0.2 Cr-MIL-101 benefits from the unique pore structure and abundant active sites of the modified MOFs.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2014
·
IF 3.633
Wei Yao,Tao Ni,Shujun Chen,Hao Li,Yun Lu
Novel hybrid nanocomposites constructed via anchoring the Fe 3 O 4 @polypyrrole nanospheres with hierarchical porous structure on graphene nanosheets (graphene/Fe 3 O 4 @polypyrrole, GFP) have been prepared, and characterized by using TEM, XRD , XPS, FT-IR and TGA . The large saturation magnetization of 12.4 emu g −1 allows fast and economic separation of the GFP from solution. Due to the synergic effect between graphene and Fe 3 O 4 @polypyrrole, the GFP exhibits excellent adsorption capability of 348.4 mg g −1 for Cr(VI) removal, which is much higher than the previously reported values of other magnetic nanomaterials . Furthermore, the GFP is stable and recyclable, retaining about 72.2% of the removal efficiency after six adsorption–desorption cycles. The adsorption isotherms and kinetics could be well simulated by the Langmuir and pseudo-second-order models respectively. The GFP nanocomposites could be a good candidate for efficient Cr(VI) removal from the wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2021
·Vol. 26
·期 22
·7054
·
IF 4.412
Juan Liang,Chengjun Jing,Jiarong Wang,Yupawang Men
Graphitic carbon nitride (g-C3N4) photocatalysts were synthesized via a one-step pyrolysis process using melamine, dicyandiamide, thiourea, and urea as precursors. The obtained g-C3N4materials exhibited a significantly different performance for the photocatalytic reduction of Cr(VI) under white light irradiation, which is attributed to the altered structure and occupancies surface groups. The urea-derived g-C3N4with nanosheet morphology, large specific surface area, and high occupancies of surface amine groups exhibited superior photocatalytic activity. The nanosheet morphology and large surface area facilitated the separation and transmission of charge, while the high occupancies of surface amine groups promoted the formation of hydrogen adsorption atomic centers which were beneficial to Cr(VI) reduction. Moreover, the possible reduction pathway of Cr(VI) to Cr(III) over the urea-derived g-C3N4was proposed and the reduction process was mainly initiated by a direct reduction of photogenerated electrons.Keywords:Cr (VI) reduction;photocatalytic;g-C3N4precursors;nanosheet morphology;surface characteristics
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Yunqi Zhou,Ye Yuan,Xinlei Liu,Zhi Wang
Metal-organic framework (MOF) membranes with proper pore size distribution and functional groups are generally more suitable for separation. Most MOFs are characterized by a hierarchical pore structure, which possesses large cavities surrounded by small windows. Fabrication of MOF membranes only retaining microporous fragment structure is a workable method to narrow pore size distribution. In this study, well-grown NH 2 -MIL-101(Cr) fragment membranes were fabricated for CO 2 separation by adjusting acetic acid – ligand – metal ratio to balance the nucleation and growth. NH 2 -MIL-101(Cr) fragment has a similar chemical structure to NH 2 -MIL-101(Cr) as expected, but only small pores with size around 0.56 nm is retained. The NH 2 -MIL-101(Cr) fragment membranes exhibited CO 2 /N 2 selectivity of about 37 with CO 2 permeance up to 6104 GPU.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2021
·Vol. 8
·期 5
·1389-1397
·
IF 8.131
Cheng Cheng,Dongyun Chen,Najun Li,Hua Li,Qingfeng Xu,Jinhui He,Jianmei Lu
Hexavalent chromium (Cr(VI)) poses a serious threat to the environment and human health due to its high-toxicity and carcinogenicity. For efficient removal of Cr(VI), semiconductor photocatalytic reduction methods have been investigated, especially those using hollow structures. In this work, a hollow In2S3/CdIn2S4 composite photocatalyst was prepared via ion exchange for the reduction of Cr(VI). The microstructure, composition, optical properties, and elements of the In2S3/CdIn2S4 composites were characterized via scanning electron microscopy, X-ray diffraction, UV-vis diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy. Because of the molecular level heterojunction constructed through ion exchange and the hollow structure, the prepared photocatalyst demonstrated excellent catalytic properties for Cr(VI) reduction. Besides, a Cr(VI) aqueous solution (50 mg L−1) was reduced within 12 min. Importantly, the activity and structure of the photocatalyst were maintained after five cycling experiments, which demonstrates its advantageous stability. Finally, the photocatalytic mechanism is discussed in detail.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2021
·Vol. 8
·期 4
·1057-1066
·
IF 8.131
Qiaohong Su,Adnan Ali Khan,Zhi Su,Chen Tian,Xiaoqin Li,Jiahua Gu,Ting Zhang,Rashid Ahmad,Xintai Su,Zhang Lin
Adsorbents with excellent redox or adsorption properties are beneficial for the efficient removal of heavy metals. In this work, a novel nitrogen-doped KFeS2/C composite (NSC-1.3) was first prepared by a simple one-step pyrolysis method and used to effectively remove Cr(VI) from aqueous solutions. The kinetics and adsorption isotherms of Cr(VI) were in accordance with pseudo-second-order kinetic and Langmuir models, respectively. The maximum adsorption capacity of NSC-1.3 was 575.68 mg g−1 at 318 K and 326.8 mg g−1 at 298 K. The removal mechanism of Cr(VI) by NSC-1.3 was first discussed by X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) simulation. The XPS analysis showed that nitrogen or carbon functional groups provide abundant active sites for Cr(VI) adsorption, and Sn2− or S8 in NSC-1.3 reduces highly toxic Cr(VI) to less toxic Cr(III). The XPS analysis showed that the removal mechanism of Cr(VI) was through adsorption and redox reaction, but the dominant one was the redox reaction. DFT simulations showed that N atoms doping was feasible and thermodynamically stable. In addition, H2CrO4 makes stronger intermolecular hydrogen bonds and larger adsorption energies with the N-doped KFeS2 layer during the adsorption process, indicating that the N-doped system has a higher adsorption capacity for Cr(VI). This study confirms the importance of the adsorption and redox reaction mechanism of this new composite material, and has promising potential for the removal of highly toxic Cr(VI) from aqueous solutions.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2021
·
IF 4.089
Dan Luo,Shao-zhong Hu,Ting Huang,Nan Zhang,Yan-zhou Lei,Yong Wang
The development of an efficient, economical, and environmentally friendly monolithic adsorbent for the removal of toxic hexavalent chromium Cr(VI) has invariably been a topic of great concern to researchers. In this paper, cellulose acetate (CA) and polyethylenimine (PEI) homogeneously blending porous fiber membranes with high porosity were successfully prepared by electrospinning, and PEI was further immobilized by cross-linking to form a stable biological adsorbent. The adsorption behavior and eliminating mechanism toward Cr(VI) by the CA-c-PEI fibrous membranes were comprehensively explored. The maximum adsorption capacity was up to 285.7 mg/g (25 °C), higher than most of the biomass-based adsorbents. Specifically, the concentration of Cr(VI) could be dramatically reduced from the initial 50 mg/L to 0.03 mg/L, much lower than the concentration standard for drinking water recommended by the World Health Organization. Even after being reused several times, the fibrous membrane still exhibited high removal efficiency.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Meng Lan,Hanbing Jia,Xiaoli Dong,Nan Zheng,Xue Li,Yu Wang,Helezi Zhou
The development of highly competent and economical photocatalysts for competent erasure of heavy metal pollutants in water is of momentous import but still a significant challenge. Herein, 3D/0D SnIn 4 S 8 /Cd 0.5 Zn 0.5 S heterostructure photocatalyst was resoundingly fabricated through integrating Cd 0.5 Zn 0.5 S nanoparticles on the surface of SnIn 4 S 8 microsphere via a simple solvothermal method and applied to high efficiency photoreduction Cr(VI). The fabricated SnIn 4 S 8 /Cd 0.5 Zn 0.5 S with optimized composition ratio achieves the exceptional reduction Cr(VI) property and the photoreduction efficiency of 20 % SnIn 4 S 8 /Cd 0.5 Zn 0.5 S can reach 91.1 % within 30 min visible light illumination. The prominent photocatalytic efficiency comes from the intimate contact of heterostructure interface, which effectively expedites the separation and migration of carrier and inhibits the photocorrosion of photocatalyst. This work provides a promising photocatalyst for water environment remediation, and promotes the exploration of heterostructure photocatalyst for wastewater purification.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）