JOURNAL OF HAZARDOUS MATERIALS
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2019
·
IF 7.65
Peng Liao,Binrui Li,Lin Xie,Xiaoao Bai,Han Qiao,Qianqian Li,Biwei Yang,Chongxuan Liu
Engineered nanoparticles-mediated contaminant transport has been recognized as a significant process governing the mobility of metals and radionuclides in groundwater. Engineered silicate nanoparticles (ESNPs) are attractive materials for the sequestration or extraction of Cr(VI) and other metals and radionuclides from groundwater. While great efforts have been devoted toward the application of these materials for Cr(VI) sequestration, the underlying interface adsorption mechanism is not thoroughly elucidated. This study investigates the immobilization mechanisms of Cr(VI) on a representative ESNPs, NH 2 -MCM-41, over a range of water chemistry conditions. By combining batch adsorption experiments with an array of complementary characterizations, we provided spectroscopic and microscopic evidence that the electrostatic interactions between the positively charged NH 2 -MCM-41 surface derived from amino functionality and the negatively charged Cr(VI) species was the dominant mechanism responsible for Cr(VI) immobilization. In addition, the weak hydrogen bonding interactions may also contribute to adsorption to a degree. Furthermore, thermodynamic studies suggested a favorable, spontaneous, and exothermic adsorption process. Site energy analysis illustrated that the distribution of energy binding sites on NH 2 -MCM-41 is Cr(VI) loading dependent. The new insights provided here can advance understanding of the transport of Cr(VI) associated NH 2 -MCM-41 that benefits the application of ESNPs-based technologies for metals immobilization in groundwater.
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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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高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 6
·065902
·
IF 1.449
Liguang Xiao,Xiaotong Zhang,Gang Yan
The Cr(VI) is a acute toxic and bioaccumulated pollutant in wastewater, the removal of these contaminants is particularly significant. Semiconductor photocatalysis is an effective method to reduce the Cr(VI) in the wastewater. In this paper, diatomite/Bi2S3 composite photocatalysts are synthesized by a facile in suit hydrothermal vulcanization method using bismuth nitrate and thiourea as precursors and diatomite as supporting materials. The structural information, morphologies, chemical states and optical properties of the composite are characterized by XRD, SEM, XPS and DRS. Under visible light irradiation (λ > 400 nm), the diatomite/Bi2S3 composite exhibit better photocatalytic reduction activity of Cr(VI) than the pristine Bi2S3. The photocatalytic mechanism is further investigated by the active species capturing tests and photoelectrochemical measurements.
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高影响因子
ORGANOMETALLICS
·
2022
·
IF 3.837
Tongshun An,Chenwei Liu,Yanzhao Yin,Xiao-Feng Wu,Zhiping Yin
A general palladium and silver co-catalyzed denitrogenative carbonylation of benzotriazoles for the synthesis of benzoxazin-4-ones has been developed. Employing benzotriazoles as easily accessible substrates and Cr(CO)6 as bench-stable solid carbonyl sources, various benzoxazin-4-ones were synthesized through a ring-opening/denitrogenative/carbonylation cascade processes in moderate to good yields. Notably, this protocol avoids the use of toxic CO gas and special equipment and can also be applied to the late-stage functionalization of substrates derived from the uricosuric agent probenecid.
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高影响因子
Frontiers of Environmental Science & Engineering
·
2021
·Vol. 15
·期 6
·1-12
·
IF 4.357
Meng Fanling,Xia Yunxue,Zhang Jianshuai,Qiu Dong,Chu Yaozhu,Tang Yuanyuan
Chromium slag usually contains various heavy metals, making its safe treatment difficult. Glass-ceramic sintering has been applied to resolve this issue and emerged as an effective method for metal immobilization by incorporating heavy metals into stable crystal structures. Currently, there is limited knowledge about the reaction pathways adopted by multiple heavy metals and the co-stabilization functions of the crystal structure. To study the Cu/Cr co-stabilization mechanisms during thermal treatment, a simulated system was prepared using a mixture with a molar ratio of Al 2 O 3 :Fe 2 O 3 :Cr 2 O 3 : CuO = 1:1:1:3. The samples were sintered at temperatures 600–1300°C followed by intensive analysis of phase constitutions and microstructure development. A spinel phase (CuFe x Al y Cr 2− x − y O 4 ) started to generate at 700°C and the incorporation of Cu/Cr into the spinel largely complete at 900°C, although the spinel peak intensity continued increasing slightly at temperatures above 900°C. Fe 2 O 3 /Cr 2 O 3 was more easily incorporated into the spinel at lower temperatures, while more Al 2 O 3 was gradually incorporated into the spinel at higher temperatures. Additionally, sintered sample microstructures became more condensed and smoother with increased sintering temperature. Cu / Cr leachability substantially decreased after Cu/Cr incorporation into the spinel phase at elevated temperatures. At 600°C, the leached ratios for Cu and Cr were 6.28% and 0.65%, respectively. When sintering temperature was increased to 1300°C, the leached ratios for all metal components in the system were below 0.2%. This study proposes a sustainable method for managing Cu/Cr co-exist slag at reasonable temperatures.
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高影响因子
SYNTHETIC METALS
·
2016
·
IF 2.299
Jianyu Ren,Xiongyi Huang,Ning Wang,Kezhen Lu,Xingxiang Zhang,Wei Li,Dongqin Liu
A composite nanofibers mat containing polyacrylonitrile (PAN) as core and polyaniline (PANI) as sheath had been successfully prepared via solution spinning followed by in situ polymerization, and its hexavalent chromium (Cr(VI)) removal potential was investigated. By altering the processing parameters, bead-free and uniform PAN nanofibers with average diameter of 469 nm could be obtained. The morphological evolution of the PANI/PAN composite fiber mats could be controlled through regulating the molar ratio of oxidant to monomer. The PANI/PAN composite fiber mats presented a superior Cr(VI) adsorption performance. Moreover, the factors affecting the performance of Cr(VI) removal from the aqueous solutions were investigated systematically. The experimental data were fitted to various kinetic models and isothermal adsorption, and the thermodynamic parameters of adsorption process were calculated as well. The PANI/PAN adsorbents were also proven to have good recycling capability, and the mechanism of adsorption and regeneration was investigated in detail.
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高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2016
·Vol. 91
·期 11
·2842-2851
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IF 2.738
Dingsheng Chen,Chaoping Cen,Jinxi Feng,Chunyang Yao,Waiqing Li,Shuanghong Tian,Ya Xiong
BACKGROUND It is of great interest to use pillared clay (PILC) as a cheap support for a selective catalytic reduction (SCR) catalyst. Al-Cr pillared clay (AlCr-PILC) has high thermal stability due to the introduction of polycations of Al. As a support, AlCr-PILC may show a co-catalytic effect in SCR processes because chromium oxide itself is an active SCR catalyst. The aim of this work is to investigate the potential of AlCr-PILC as a new low temperature SCR catalyst support. RESULTS A series of AlCr-PILC with Al:Cr molar ratio varying from 0:4 to 4:0 were successfully synthesized to support manganese and cerium active phase. MnCe/AlCr(2:2)-PILC exhibited the highest NO x conversion close to 100% at 200–300 °C, and more than 90% N 2 selectively over a wide temperature window of 140–300 °C. The catalytic activity of MnCe/AlCr-PILC in terms of both NO x conversion and N 2 selectivity is much higher than those of MnCe/Al-PILC, MnCe/Cr-PILC, AlCr-PILC, and the simple mixed MnCeAlCr, indicating the co-catalytic effect of AlCr-PILC support. CONCLUSION AlCr-PILC is a very promising low-temperature SCR catalyst support. The XRD, XPS, and H 2 -TPR measurements prove that the co-catalytic effect of AlCr-PILC occurred via the strong interaction between MnCe and the AlCr-PILC support. © 2016 Society of Chemical Industry
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高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Yi Wan,Wenrui Wei,Rizwan Haider,Liang Wu,Xufang Qian,Xianxia Yuan
Achieving the efficient construction and regulation of active sites in complex high-entropy system is crucial for developing high-entropy alloys (HEAs) as top-notch catalysts for hydrogen evolution reaction (HER). Herein, a rapid thermal shock process coupled with Cr content regulation was employed to fabricate a self-supporting PtFeCoNiCuCr0.5@CC-720 as HEAs material, which bears a low HER overpotential of 83 mV to achieve 100 mA cm-2 in KOH electrolyte. Based on experiments and density functional theory (DFT) calculations, the influence of Cr content on microstructure as well as HER electrocatalytic activity was elucidated. It was revealed that incorporation of Cr enhances the crystallinity of HEAs material, accelerates the electron transfer rate, and modulates the electronic configuration of active sites due to its low electronegativity induced electron donating effect. As a result, the d-band center of Pt sites was shifted towards Fermi level, leading to optimized Gibbs free energy for hydrogen species adsorption/desorption and improved HER activity. This work offers a perspective for rapid regulation of HER activity in high entropy alloys and is helpful for designing electrocatalysts with enhanced activity.
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2024
·
IF 3.2
Yuan Zhou,Jin-Long Jiang,Xia-Ping Zhu,Wen Chen
In this study, attapulgite (ATP) was modified by Zr-based metal organic framework (UiO-66-NH 2 ) and poly(hexamethylenediamine-tannic acid) (HTA), an amino material named UiO-66-NH 2 /HTA/ATP (UHA) was prepared to efficiently remove Cr(VI). The morphology and structure of UHA were analyzed through various characterization methods. The conditions and influencing factors of UHA preparation and Cr(VI) adsorption were studied. The material had a maximum adsorption capacity of 270.3 mg/g for Cr(VI) when pH was 2.0, temperature was 298 K, adsorption time was 300 min, and ionic strength was 0.01 mol/L, which was obtained by the Langmuir fitting model. The adsorption process conforms to the pseudo-second-order kinetic and Langmuir isothermal models, indicating that the adsorption process is mainly based on the chemical adsorption of monolayers. X-ray photoelectron spectroscopy analysis shows that UHA mainly removes Cr(VI) by hydrogen bonding , electrostatic attraction, reduction, and complexation. Thermodynamic investigation suggested a disordered, endothermic and spontaneous adsorption process. After UHA treatment, the simulated wastewater containing Cr(VI) met the discharge standard, and the results of cycling experiments showed that UHA has good renewable performance and offers potential prospects for Cr(VI) removal in water.
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高影响因子
Journal of Water Process Engineering
·
2025
·
IF 6.7
Umer Hayat,Shafuq Abbas,Yingjie Xiao,Rohan Weerasooriya,Xing Chen
Hexavalent chromium (Cr(VI)) is a hazardous and mobile contaminant noted for its severe environmental impacts. This research presents a low-cost, efficient, and eco-friendly method that utilizes starch extracted from Maranta arundinacea (arrowroot) for the selective recovery and discarding of chromium (VI) from electroplating effluents driven by a visible light photochemical procedure. This method alleviates the transition of harmful and toxic Cr(VI) into the less toxic and more stabilized trivalent chromium (Cr(III)), which eventually forms firm coordination complexes with the arrowroot starch along with functional groups such as hydroxyl groups ( OH) and ether groups (C O C), as verified by FTIR and XPS analyses. Noticeable structural alteration in the starch matrix was observed upon interaction with chromium ions. At pH 3.0, the process achieved a maximum removal limit of 98.3 %, but at pH 10.0, the efficiency decreased markedly to 3.2 %. Additionally, within the tested concentration range of 10–50 mg/L, the extraction efficiency remained at or above 90 %. In the presence of competing ions such as Ca, Cu, Zn, and Ni, chromium was selectively removed. Furthermore, when the starch dosage was increased from 50 mg to 450 mg, the efficiency was enhanced by approximately 55 % to nearly 95 %. This increase in dosage promoted the faster reduction within 300 min. The entire approach is environmentally benign, generating no secondary waste, and thus making it a viable and sustainable option for industrial-scale wastewater treatment. These results demonstrate the potential value of arrowroot starch as an efficient material for sustainable and economical chromium remediation.
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高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Zhuan-nian Liu,A.-ping Fan,Xiao-gang Han,Habiba Shapour,Qing-yun Zhang
The chelating adsorbent PEI-MIL-101(Cr) was prepared by introducing polyethyleneimine (PEI) into the MIL-101(Cr) channel in this paper. X-ray diffractometer, Fourier transform infrared spectrometer and scanning electron microscope were applied to characterize the structure and morphology of MIL-101(Cr) and PEI-MIL-101(Cr). The adsorption properties and mechanism of the MIL-101(Cr) and PEI-MIL-101(Cr) to Cr(VI) were studied. The results showed that adsorption capacity of PEI-MIL-101(Cr) for Cr(VI) was obviously better than MIL-101(Cr). The adsorption isotherm of Cr(VI) onto MIL-101(Cr) and PEI-MIL-101(Cr) can be described by Langmuir model. The maximum adsorption amount for Cr(VI) onto MIL-101(Cr) and 30% PEI-MIL-101(Cr) was 61.99 and 40.34 mg/g. The adsorption kinetic data of the two adsorbents followed the pseudo second-order model. The negative values ΔH and ΔG illustrate that the process is spontaneous and exothermic. PEI-MIL-101(Cr) can be reused for four times.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Ruinan Wang,Shuang Ni,Gang Liu,Xiaoxiang Xu
In this work, we have applied microstructure management and doping techniques to conventional wide band gap semiconductor CaTiO 3 with the aim to improve its light absorption and photocatalytic activity. A series of La/Cr co-doping hollow CaTiO 3 cubes have been successfully prepared by a template-free hydrothermal method. Their crystal structures, microstructures, optical absorption and photocatalytic hydrogen production have been systematically investigated. Our results suggest that hollow CaTiO 3 owns a higher light absorption than solid one and demonstrates a much better photocatalytic activity both under full range (λ ≥ 250 nm) and visible light illumination (λ ≥ 400 nm). These improvements probably originate from the peculiar hollow microstructures that increase photon-matter interactions and shorten the charge migration pathways. The photocatalytic activity for hydrogen production has been further studied by varying the La/Cr content in CaTiO 3 . An optimal doping point at 5% La/Cr doping level has been reached for full range illumination with apparent quantum efficiency approaching ∼2.41%. Nevertheless, the activity under visible light illumination shows a clear dependence on doping level with highest apparent quantum efficiency ∼0.40% at 20% La/Cr doping level. DFT calculations reveal the critical role of Cr in forming a new spin-polarized valence band inside the original band gap of CaTiO 3 therefore is responsible for band gap reduction and visible light photocatalysis. This work here highlights the importance of microstructure control to the photocatalytic performance and shall shed a light on the design and development of efficient photocatalytic materials/systems.
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