SCIENCE OF THE TOTAL ENVIRONMENT
·
2018
·
IF 4.61
Shunquan Shi,Jiakuan Yang,Sha Liang,Mingyang Li,Quan Gan,Keke Xiao,Jingping Hu
Fe 3 O 4 @SiO 2 -NH 2 magnetic particles with core-shell structure were attached on carboxylated biochar derived from phoenix tree leaves to synthesize a novel magnetic biochar for removing Cr(VI) ions from acidic solutions. FSEM, FTEM, XRD characterizations of the synthesized magnetic biochar revealed that the Fe 3 O 4 @SiO 2 -NH 2 magnetic particles distributed uniformly on the surface or macrospores of carboxylated biochar by strong chemical bonding. The Cr(VI) ions adsorption capacity of magnetic biochar was 27.2 mg·g −1 , surpassing original carboxylated biochar (18.2 mg·g −1 ). VSM and XPS characterizations demonstrated that the attached Fe 3 O 4 @SiO 2 -NH 2 magnetic particles not only endowed biochar with perfect magnetic property (23 emu·g −1 ) but also provided complexing sites for binding Cr(III) cations reduced from Cr(VI) anions. The Cr(VI) ions removal by magnetic biochar contained three steps: (1) adsorption of Cr(VI) anions by protonated functional groups; (2) reduction of Cr(VI) anions to Cr(III) cations by electron-donor groups; and (3) chelation of Cr(III) cations by amine groups. The adsorption recycling test showed that magnetic biochar kept 85% of its initial Cr(VI) adsorption capacity at the sixth cycle, and the Fe leakage under pH 1.0 was smaller than 0.25 mg·L −1 . The results indicated that this novel magnetic biochar was applicable for the practical treatment of Cr(VI)-containing wastewater.
研究领域:
环境科学
·
材料科学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yangjie Fu,Kejie Zhang,Yi Zhang,Yanqing Cong,Qi Wang
Visible-light-active MR/NH 2 -MIL-125(Ti) homojunction was successfully synthesized via post-synthetic modification of NH 2 -MIL-125(Ti). A chromophore group (–MR) similar to the structure of methyl red, was introduced to partially replace the –NH 2 group. Using pure NH 2 -MIL-125(Ti) and MR-MIL-125(Ti) as control samples, the possible structural and optical changes were carefully studied. It was found that the lattice structure remained unchanged, while the specific surface area and band gap were in the order of NH 2 -MIL-125(Ti) > MR/NH 2 -MIL-125(Ti) > MR-MIL-125(Ti). Despite of these, MR/NH 2 -MIL-125(Ti) exhibited highest photocurrent response and lowest charge transfer resistance, which were associated with optimal photocatalytic performance. For the photocatalytic reduction of Cr(VI), the estimated rate constant on MR/NH 2 -MIL-125(Ti) was ca. 9 times and 3 times relative to that on NH 2 -MIL-125(Ti) and MR-MIL-125(Ti), respectively. Besides, 4.6 times rate enhancement can also be observed on the homojunction relative to physical mixture (MR/NH 2 -MIL-125(Ti)-PM). The boosted photocatalytic performance may be ascribed to promoted separation and transfer of photogenerated electron-hole pairs. The operating factors was optimized at acidic pH (2.0), lower catalyst dosage (0.1 g/L) and appropriate concentration of coexisting organics (2.0 mM) within the tested range. Furthermore, good stability both in photocatalytic performance and structure were also observed after 5 cyclic runs. Thus, this study report a facile way for the construction of visible-light-active MOFs, and provided a stable photocatalytic candidate for the disposal of Cr(VI)-containing wastewaters.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2017
·
IF 6.035
Mingmin Jia,Yi Feng,Shichang Liu,Jianhao Qiu,Jianfeng Yao
UiO-66-NH 2 were either intercalated into graphene oxide (GO) layers (GOU@S) or covered by GO layers (GO/U@S) to form UiO-66-NH 2 /GO composite membrane . Results show that different synthesis methods would lead to different membrane morphology, thickness and gas separation performance. For GOU@S membrane, UiO-66-NH 2 was well-dispersed and intercalated into GO layer, whereas two continuous layers (GO and UiO-66 layer) with an obvious boundary were observed for GO/U@S. Due to the morphology and structure difference, better hydrogen separation performance was achieved for GOU@S membrane compared to GO/U@S membrane and pristine membrane due to the close interfacial contact between UiO-66-NH 2 and GO, which arises from the hydrogen bonding formed between -NH 2 group in UiO-66-NH 2 and -OH group in GO and the electrostatic force between UiO-66-NH 2 and GO layers. The ideal selectivities of H 2 /N 2 and H 2 /CO 2 were increased to 9.75 and 6.35, respectively, for the GOU@S membrane with a H 2 permeance of 3.9 × 10 −8 mol m −2 s −1 Pa −1 .
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
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Jialin Niu,Yulong Xiang,Xiaoli Dong,Yu Wang,Nan Zheng,Pei Yu
Hexavalent chromium in industrial wastewater poses a serious threat to ecosystems. Photocatalytic technology has been seen as a promising strategy for removing heavy metal ions. Construction of heterostructures offered a promising strategy to enhance the separation efficiency of photogenerated carriers, thereby improving photocatalytic performance. Herein, ZnWO 4 /UiO-66-NH 2 heterostructures were synthesized by a two-step hydrothermal method. The synthesized samples were systematically characterized via a variety of techniques, alongside an exploration of the associated photocatalytic mechanism. ZnWO 4 /UiO-66-NH 2 -2 exhibited an exceptional photocatalytic performance, attaining a 97 % degradation of hexavalent chromium within 60 min, approximately 1.3 and 4.7 times that of UiO-66-NH 2 and ZnWO 4 , respectively. The transient photocurrent response, photoluminescence (PL), and electrochemical impedance spectroscopy (EIS) results indicate that constructing heterostructures can effectively accelerate the migration of electrons while simultaneously suppressing the recombination process of photogenerated carriers. In addition, Active species trapping experiments revealed that the photogenerated electrons were the main active substances in photoreduction reaction. This study offers an effective strategy for photocatalytic reduction of hexavalent chromium.
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Shubo Wang,Yuan Lin,Jian Yang,Lei Shi,Guang Yang,Xupin Zhuang,Zhenhuan Li
Metal–organic frameworks (MOFs) exhibit high proton conductivity , thermal stability, and offer immense flexibility in terms of tailoring their size. Owing to their unique characteristics, they are desirable candidates for proton conductors . Nevertheless, constructing ordered MOF proton channels in proton exchange membranes (PEMs) remains a formidable challenge. Herein, blend nanofibers of cellulose and UiO-66-NH 2 (Cell–UiO-66-NH 2 ) obtained via the electrospinning process were embedded in a sulfonated polysulfone matrix to obtain high-performance composite PEMs with an orderly arrangement of UiO-66-NH 2 . Comprehensive characterization and membrane performance tests reveal that composite membrane with 5 wt% (nominal) UiO-66-NH 2 have revealed high proton conductivity of 0.196 S cm −1 at 80 °C and 100% relative humidity. Meantime, the composite membrane exhibits a low methanol permeability coefficient (~5.5 × 10 −7 cm 2 s −1 ). Moreover, the composite membrane exhibits a low swelling ratio (17.3%) even at 80 °C. The Cell–UiO-66-NH 2 nanofibers exhibit strong potential for use as a proton-conducting nanofiller in fuel-cell PEMs.
研究领域:
材料科学
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能源科学
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产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2021
·Vol. 327
·期 2
·811-819
·
IF 1.371
Du Ziyao,Li Bolin,Jiang Chao,Sun Ruopei,Chen Suwen
A metal–organic framework, UiO-66-NH 2 , was designed, synthesized and characterized in this study. By conducting solvothermal method, Salicylaldehyde (Sal) and 2,4-dihydroxybenzaldehyde (MHBA) were grafted onto UiO-66-NH 2 via post-treatment to obtain the functionalized material UiO-66-Sal and UiO-66-MHBA. The three materials above were characterized, and the effects of solid–liquid ratio, pH, ionic strength, and oscillation time on U(VI) adsorption were studied. The relevant experimental results fitted well with pseudo-second-order kinetic equation and thermodynamic adsorption model.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2022
·
IF 14.224
Shenglong Tian,Zede Yi,Junqing Chen,Shiyu Fu
The capture of radioactive iodine is an inevitable requirement in nuclear industry for environmental protection. Metal-organic frameworks (MOFs) are a new generation of sorbents that have wide applications for iodine adsorption and recovery. Although the loading of MOFs on wood can avoid the drawbacks of the powder form of MOFs in implementation, the dense structure of wood results in the lower loading, even after delignification, which limits the adsorption capacity. Herein, a hierarchically porous UiO-66-NH 2 @WCA composite was fabricated by in-situ synthesis of UiO-66-NH 2 in wood-derived cellulose aerogel (WCA) that was further removed hemicellulose from delignified wood. UiO-66-NH 2 @WCA exhibited a high loading (36 wt%) of UiO-66-NH 2 crystals and a high adsorption capacity of 704 mg/g for iodine vapor and 248 mg/g for iodine aqueous solution. The adsorption behavior in iodine aqueous solution was well predicted by the Freundlich isotherm and pseudo-second-order kinetic model. The adsorption capacity of UiO-66-NH 2 @WCA was highest in solution when the pH was 6, while the ionic strength had little effect. The hydroxyl groups on the WCA matrix had a charge transfer effect with iodine, providing additional sites for iodine capture . Furthermore, a packed column system was applied to demonstrate the excellent recyclability and potential for practical application.
研究领域:
材料科学
·
环境科学
·
核工业
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Chunhua Li,Luqian Bao,Yubo Shi,Zhehang Tian,Yixin Ji,Mengyao Cui,Zhilei Zhao,Xianyou Wang
A hollow heterojunction of W-Zr-MOF-NH 2 @TpTt-COF (WZT) was fabricated by combining etched W-Zr-MOF-NH 2 with TpTt-COF. WZT, synthesized through acid etching and hydrothermal methods, showed better tetracycline degradation than pure W-Zr-MOF-NH 2 and pure TpTt-COF due to its larger specific surface area and more active sites. The surface of WZT contains abundant oxygen vacancies (OVs) that capture electrons, promoting the separation of photogenerated e - -h + pairs and increasing WZT’s photocatalytic activity. WZT (1:1, mass) showed 87% degradation of tetracycline under 300 W Xenon lamp irradiation. The results of cycling experiments demonstrated the high stability and reusability of WZT (1:1), making it feasible for production. The excellent photocatalytic degradation of tetracycline by WZT (1:1) originates from the formation of heterojunctions and the presence of surface OVs, which reduces the strong photogenerated e - -h + complexation efficiency. Possible photocatalytic degradation mechanisms are proposed while demonstrating the formation of Z-scheme heterojunction in WZT, which aligned with the experimental results of electron spin resonance (ESR). The tetracycline oxidative decomposition process involves the participation of •OH, 1 O 2 , • O 2 - , e - , and h + as proven by ESR and radical trapping experiments. This work proposes a research idea to prepare high-performance photocatalysts with MOF@COF type, featuring OVs-rich and Z-scheme heterojunctions.
研究领域:
材料科学
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环境科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Chen Li,Chuncai Zhou,David French,Ian T. Graham,Zixuan Wang,Yunfei Li,Feng Wang,Guijian Liu
As strategic emerging industries represented by clean energy technologies develop rapidly, gallium (Ga), one of the critical elements due to its use in these technologies and limited supply, has attracted worldwide attention. The discovery of appropriate materials to adsorb Ga is crucial for improving the utilization of Ga resources. With the goal to recover Ga ions more efficiently and selectively, carbon nanotubes (CNTs) and amino-functionalized MIL-53 series metal–organic skeletons were hydrothermally synthesized into CNT/NH2-MIL-53(Fe) composite adsorbents. The composite's morphology, structure, chemistry and other physicochemical features were characterized, and the adsorption conditions including pH, initial Ga concentration, along with adsorbent dosage were optimized. The outcomes suggest that 2-CNT/NH2-MIL-53(Fe) performs better than the unmodified material in adsorption, and the theoretical maximum adsorption amount of Ga is 1483.8 mg g−1. The adsorption exhibited a single layer chemisorption with an endothermic spontaneous reaction. The adsorption mechanism for Ga onto 2-CNT/NH2-MIL-53(Fe) was mainly via ion exchange and chelation, accompanied by hydrogen bond interaction. The outstanding adsorption capacity and reproducibility using CNT/NH2-MIL-53(Fe) composites provide a novel method for adsorbing Ga from aqueous solutions.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 3
·1757-1768
·
IF 3.119
Yiqiu Liu,Yi Zhou,Qijun Tang,Qian Li,Si Chen,Zhuxing Sun,Haiqiang Wang
To explore an efficient photocatalyst for NO pollution, a direct Z-scheme photocatalytic system is successfully fabricated by coupling Bi2WO6 with NH2-UiO-66 via a simple hydrothermal synthesis technique. The Z-scheme system promotes the NO photocatalytic oxidation activity with an optimum NO removal rate of 79%, which is 2.7 and 1.2 times that obtained by using only pristine Bi2WO6 and NH2-UiO-66, respectively. Simultaneously, superior selectivity for converting NO to NO3−/NO2− is observed. The enhanced photocatalytic performance of the Bi2WO6/NH2-UiO-66 hybrids is attributed to the following two aspects: (i) large specific area of NH2-UiO-66, which exposes more active sites and is beneficial to the adsorption and activation of NO; (ii) outstanding Z-scheme structure constructed between BiWO6 and NH2-UiO-66, which can improve the efficiency of the separation of electron–hole pairs and preserves the strong oxidation ability of hybrids. ESR analysis shows that ·O2− and ·OH contribute to NO removal. A possible photocatalytic mechanism of NO oxidation on the direct Z-scheme photocatalyst (BWO/2NU) under visible light irradiation is proposed. This work displays the BWO/2NU hybrid's potential for treating low-concentration air pollutants, and the proposed Z-scheme photocatalyst design and promotion mechanism may inspire more rational synthesis of highly efficient photocatalysts for NO removal.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Shusu Shen,Honglin Li,Yang Shen,Renbi Bai,Ganwei Zhang
Metal organic frameworks (MOFs) possess excellent post-modification characteristics, high specific surface area, diversity of skeleton composition and pore tunability, have been increasingly applied in membrane modifications. In this work, NH 2 -MIL-88B(Fe) (NM88B) was first fixed onto polyvinylidene fluoride (PVDF) membrane by polyethyleneimine (PEI) through a vacuum-assisted self-assembly process, and the deposited NM88B was subsequently grafted with perfluoroalkyl polyethoxyacetic acid (FPEOAA) via a condensation reaction to realize the surface modifications. The modified membranes (named as N1F x ) showed improved hydrophilicity and underwater-oleophobicity. In addition, very high pure water flux (up to 9403 L‧m −2 ‧h −1 ) was obtained for the N1F x membranes due to the high porosity of introduced NM88B. In the dead-end filtration experiments of n -hexadecane-water emulsion, the optimum membrane N1F20 showed a good oil rejection rate (98.3%) and high permeation flux (667 L‧m −2 ‧h −1 ) which is approximately seven times of the pure PVDF membrane, indicating that the surface-modified membranes had excellent permeability and good separation performance. Even after four filtration cycles of oil-water emulsion, the rejection rate maintained higher than 97%, showing good reusability. Furthermore, the study found that N1F20 had certain acid and alkaline resistance and great potential for engineering applications.
研究领域:
材料科学
·
环境工程
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING & TECHNOLOGY
·
2022
·Vol. 46
·期 4
·738-746
·
IF 2.215
Youhua Zhang,Linhai Duan,Ping Yang,Dan Zhang,Xiuhong Meng
Deactivation of Pd-Cr bimetallic nanopaticles supported on NH 2 -functionalized MIL-101 in dehydrogenation of formic acid is studied. Results show that the catalyst cannot be reused more than three times because the concentration of carbon monoxide in the gaseous product will exceed 10 ppm. When the catalyst is used for the first time, the turnover frequency of the active metal Pd is the highest. With an increase of catalyst utilization times, the turnover frequency decreases. The reason for the reduction in catalyst activity is agglomeration of Pd and Cr atoms on the outer surface of the catalyst, not because the active component, Pd, is being lost.
研究领域:
化学工程
·
催化科学
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产品关联
DOI
高影响因子
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