JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2025
·
IF 8.4
Yuliang Tu,Jianle Wang,Yanfeng Huang,Hong Deng,Xueming Liu,Jiaxin Lv
Hexavalent chromium [Cr(VI)] presents substantial environmental and health hazards due to its pronounced toxicity and mobility in soils. Traditional chemical reduction methods for Cr(VI) are often inadequate for treating chromium-contaminated soils, as they may fail to fully reduce Cr(VI), leading to incomplete remediation. Consequently, there is a critical need to develop more efficient and environmentally sustainable methods for the treatment of hexavalent chromium. This study explores an innovative approach using microwave-enhanced reduction of soil iron minerals facilitated by tea polyphenols to achieve transformational fixation of Cr(VI). The microwave-assisted treatment (0.5 wt% TP combined with MW at 700 W for 10 min) significantly reduced Cr(VI) concentrations in iron-rich soil from 363.4 mg kg −1 to 0.3 mg kg −1 , achieving a removal rate of 99.9%, compared to TP treatment alone (0.5 wt%). Transmission electron microscopy (TEM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analyses revealed that the enhanced removal efficiency of Cr(VI) by microwave-assisted tea polyphenols is attributable to the accelerated reduction of soil iron minerals by the polyphenols. Furthermore, microwave enhancement facilitated the transformation of Cr into more stable forms, such as Cr 2 O 3 and FeCr 2 O 4 . Additionally, the Cr(VI) content in the treated soil remained below 3 mg kg −1 after 360 days of atmospheric exposure, indicating sustained immobilization. This study demonstrates that the integration of tea polyphenols with microwave irradiation constitutes a promising strategy for the remediation of Cr(VI)-contaminated soils.
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高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Mimi Sun,Jiahui He,Wanting Xiang,Wei Zou,Wenfei Song,Yating Xi,Jun Yan,Meimei Zhou,Pingping Luo
The design and construction of diverse heterojunction architectures have emerged as an effective strategy for enhancing the photocatalytic performance of semiconductors. In this study, ZIF-8/TiO 2 composite nanofibers were successfully fabricated by combining electrospinning technology with a facile in-situ solvothermal method, followed by ZIF-8 sulfurization to form ZnS/TiO 2 nanofiber heterostructures. Comprehensive characterization confirmed that ZIF-8 on the surface of TiO 2 nanofibers was completely converted into ZnS, establishing a robust and intimate interface with TiO 2 . The resulting ZnS/TiO 2 heterojunction exhibited remarkable photocatalytic reduction activity for Cr(VI), achieving 100% removal efficiency within 20 min under visible light irradiation. The photocatalytic reaction rate constant of the ZnS@TiO 2 nanofibers was approximately 10 and 319.5 times higher than those of pristine ZnS and TiO 2 nanofibers, respectively. This enhanced photocatalytic performance is attributed to the formation of the heterojunction, which effectively narrows the bandgap of the composite, optimizes photogenerated charge transfer pathways and significantly improves electron-hole pairs separation. Furthermore, mechanistic studies identified photogenerated electrons (e − ) and superoxide radicals ( O 2 − ) as the dominant active species involved in the photocatalytic reduction process. This work provides both fundamental understanding and practical methodology for developing high-performance TiO 2 -based photocatalytic systems, highlighting their potential for advanced water purification technologies.
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高影响因子
MOLECULES
·
2025
·Vol. 30
·期 13
·2691
·
IF 4.6
Jiuhu Zhao,Jingjing Jiang,Guanyu Chen,Meng Wang,Xiaoyuan Zuo,Yanjiao Bi,Rongshu Zhu
The selective catalytic reduction of NOxwith CH4(CH4-SCR) holds the potential to simultaneously abate harmful NOxand CH4greenhouse gases. In this study, a series of bimetallic M-In/H-SSZ-39 catalysts (where M represents Cr, Co, Ce, and Fe) were prepared via an ion exchange method and subsequently evaluated for their CH4-SCR activity. The influences of the preparation parameters, including the metal ion concentration and calcination temperature, as well as the operating conditions, such as the CH4/NO ratio, O2concentration, water vapor content, and gas hourly space velocity (GHSV), on the catalytic activity of the optimal Cr-In/H-SSZ-39 catalyst were meticulously examined. The results revealed that the Cr-In/H-SSZ-39 catalyst exhibited peak CH4-SCR catalytic performance when the Cr(NO3)3concentration was 0.0075 M, the In(NO3)3concentration was 0.066 M, and the calcination temperature was 500 °C. Under optimal operating conditions, namely GHSV of 10,000 h−1, 400 ppm NO, 800 ppm CH4, 15 vol% O2, and 6 vol% H2O, the NOxconversion rate reached 93.4%. To shed light on the excellent performance of Cr-In/H-SSZ-39 under humid conditions, a comparative analysis of the crystalline phase, chemical composition, pore structure, surface chemical state, surface acidity, and redox properties of Cr-In/H-SSZ-39 and In/H-SSZ-39 was conducted. The characterization results indicated that the incorporation of Cr into In/H-SSZ-39 enhanced its acidity and also facilitated the generation of InO+active species, which promoted the oxidation of NO and the activation of CH4, respectively. A synergistic effect was observed between Cr and In species, which significantly improved the redox properties of the catalyst. Consequently, the activated CH4could further interact with InO+to produce carbon-containing intermediates such as HCOO−, which ultimately reacted with nitrate-based intermediates to yield N2, CO2, and H2O.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2014
·
IF 2.613
Shengnan Yu,Fusheng Pan,Sen Yang,He Ding,Zhongyi Jiang,Baoyi Wang,Zhuoxin Li,Xingzhong Cao
Hybrid membranes were fabricated with active layers composed of polydimethyl siloxane (PDMS) and metal organic framework MIL-101 (Cr), together with support layers composed of polyvinylidene fluoride (PVDF). Transmission electron microscopy (TEM), X-ray diffraction (XRD) and nitrogen adsorption were used to study the structure of MIL-101 (Cr) particles; scanning electron microscopy (SEM), infrared spectrum (IR), thermogravimetric analysis (TGA), thermomechanical analysis and positron anihilation lifetime spectroscopy (PALS) were employed to characterize the structural morphology, free volume property, thermal and mechanical features of the membranes. The effect of MIL-101 (Cr) incorporation on swelling and pervaporation performance of the hybrid membranes were evaluated with thiophene and n -octane mixture as model gasoline. The packing of PDMS chains was interrupted by MIL-101 (Cr), thus the fractional free volume was increased. Accordingly, the separation performance including permeation flux and selectivity was increased remarkably. The optimal performance was achieved when the weight fraction of MIL-101 to PDMS was 6% with a flux of 5.2 kg·m −2 h −1 (increased by 136% compared with the PDMS control membrane) and an enrichment factor of 5.6 (increased by 38% compared with the PDMS control membrane).
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高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jing Yang,Siyuan Yang,Jing Zhang,Jian He,Wei Jiang
ABSTRACT The recovery of Cr(VI) from the solution and the utilization of by-products are significant for waste-water treatment and environmental protection. In this study, the amorphous ZrO 2 was prepared using a solvothermal method and used to treat the wastewater containing Cr(VI). Amorphous ZrO 2 is effective for the photocatalytic reduction of Cr(VI). Without a sacrificial agent, 20 mL potassium dichromate solution (20 mg/L) is reduced to almost 0 mg/L within 10 min. Moreover, the by-products obtained from this process exhibit good performance in the catalytic dehydrogenation of ethane coupled with the reverse water–gas reaction. The maximum yield of ethylene is 12.9%, and the service life of the catalyst reached 160 min. Catalyst deactivation is caused by carbon deposition, and the deactivated catalyst is regenerated by roasting in the air. The feasibility of this green process is demonstrated, including the one-step photocatalytic reduction of Cr(VI) and utilization of the by-product as an ethane dehydrogenation catalyst.
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高影响因子
CRYSTENGCOMM
·
2022
·Vol. 24
·期 32
·5724-5732
·
IF 3.756
Boyuan Di,Pengzhen Zhang,Hongfei Yin,Peng Han,Hao Wu,Gaojie Zhang,Wen Jin,Xiaokun Wen,Wenfeng Zhang,Haixin Chang
The discovery of two-dimensional (2D) van der Waals (vdW) ferromagnets has provided a broad platform for the study of spintronics and many novel physical phenomena. However, vdW ferromagnetic crystals generally have a low Curie temperature and poor air stability and their magnetic properties are difficult to modulate. As a layered Dirac semimetal, NiTe2 has excellent properties such as high electrical conductivity and high air stability. In this work, we report for the first time the introduction of ferromagnetism into NiTe2 single crystals by doping Cr atoms with the Te-flux method. By controlling the Cr content, the Curie temperature can be tuned from 210 K to 248 K and the saturation magnetic moment from 1.54 emu g−1 to 2.27 emu g−1 which is much higher than the defective magnetism caused by doping. The doped nanosheets still have extremely high air stability, in contrast with most vdW 2D ferromagnet crystals. The results provide opportunities for the study of new highly-tunable, air-stable vdW ferromagnets and their potential applications.
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JOURNAL OF HAZARDOUS MATERIALS
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2022
·
IF 14.224
Xiaofeng Yi,Shurui Liu,Mingyu Luo,Qingbiao Li,Yuanpeng Wang
Microbe-photocatalyst biohybrids, integrating the optimal attributes of whole-cell catalysts and nanometer photocatalysts, have emerged as a promising strategy for environment-associated applications. However, few such biohybrids have been tested for complex pollution systems. Herein, we constructed an outer membrane photosensitized Geobacter sulfurreducens ( G. sulfurreducens )-CdS biohybrid, which enabled to generate stronger photocurrent in response to irradiation and meanwhile achieved an significant promotion for the redox transformation of Cr(VI) and tetracycline compared with that of bare G. sulfurreducens or CdS counterparts. Further analysis revealed that the outer membrane played a significant role in photoelectron transfer. Differential pulse voltammetry (DPV) tests demonstrated that CdS enhanced the catalytic activity of C-type cytochromes on the outer membrane under irradiation, resulting in the increase of electron-hole pairs separation efficiency. The possible degradation pathway of tetracycline was proposed based on determined intermediates, whose toxicities were well evaluated. Importantly, the toxicity of the final detected intermediates was apparently decreased. Overall, this work aims to explore the working mechanisms of the novel G. sulfurreducens -CdS biohybrid system and opens up a new avenue to purifying combined wastewater by microbe-photocatalyst biohybrids.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2018
·Vol. 165
·期 16
·B893
·
IF 3.662
Jingfang Hu,Ye Liu,Guowei Gao,Xiaoping Zou
One-step electrochemical approach for synthesis of AuPdNPs/ERGO nanocomposite has been developed for Cr(VI) sensing in water. The bimetallic AuPd nanoparticles and electrochemical reduced graphene oxide (ERGO) composite (AuPdNPs/ERGO) were reduced from H2PdCl4, HAuCl4 and GO mixed solution and deposited onto glass carbon electrode (GCE) through cyclic voltammetry, simultaneously. The bimetallic AuPdNPs were homogeneously modified on graphene nanosheets and characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) technique. Based on the voltammetric results, the bimetallic AuPdNPs/ERGO/GCE had higher catalytic activity for Cr(VI) determination, compared with AuNPs/GCE, PdNPs/GCE and ERGO/GCE obtained by the same method. The fabricated AuPdNPs/ERGO/GCE shows good relationship in two concentration ranges from 0.05 μM to 5 μM and 5 μM to 1000 μM, with a detection of 0.013 μM (at S/N = 3). In addition, the proposed modified electrode presents high selectivity, sensitivity and stability for Cr(VI) detection and a high recovery of more than 95% was obtained towards real water application, which makes it favorable for the further practical field monitoring.
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ACS ES&T Engineering
·
2022
·
IF 0
Ting Zhang,Zhelun Pan,Dinggui Song,Hong Huang,Jiang Yu,Yichan Wen,Junlin Lu,Zhenfeng Bian,Xufang Qian
The high reactivity of Fe(0) with Cr(VI) makes it the best choice for Cr(VI) removal. Interstitial compound Fe3C was produced during the carbothermic reduction of mesoporous phenolic resin/ferric ions to form Fe(0)/Fe3C nanoparticles embedded in mesoporous carbon (Fe(0)/Fe3C@MesoC). Fe3C accelerates the electrochemical corrosion process of α-Fe(0) in solution, and the positive/negative equipotential interface that is formed by iron–carbon (Fe–C) microelectrolysis of Fe(0)/Fe3C@MesoC induces the capture of Cr(VI) anions and Cr(III) cations as a result of this process. Cr(VI) was completely reduced to Cr(III) by the Fe(0)/Fe3C@MesoC catalyst with a high electron efficiency (40.5%) relative to nanosized zero-valent iron (1.9%) and Fe@MesoC (32.7%). Surface ferrous ions are the principal reactive species responsible for Cr(VI) reduction (at least 64%); Fe(0)/Fe3C and undetectable surface ferrous ions account for a small part of Cr(VI) reduction (around 28%), and only 8% of Cr(VI) ions are reduced by active hydrogen (H*). The proposed structure of Fe(0)/Fe3C@MesoC provides new insight into iron–carbon material preparation and application in in situ chemical reduction.
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RESEARCH ON CHEMICAL INTERMEDIATES
·
2023
·Vol. 49
·期 9
·3825-3846
·
IF 3.3
Liu Suyan,Qi Xiaoran,Fan Zhanpeng,Song Jianzheng,Huo Quan
A series of NCDs-decorated hematite@MIL-101(Cr) (marked as HMC) hybrids were innovatively and successfully developed for the highly efficient removal of carbamazepine in this study, which were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, N 2 adsorption–desorption, X-ray photoelectron spectroscopy, etc. And, the successful preparation of the hybrid was directly proved by XRD, FT-IR, SEM, TEM and XPS. N 2 adsorption–desorption result revealed good textural properties of the hybrid. The evaluation results indicated that the as-prepared hybrids possessed markedly promoted removal performances for CBZ. Compared with other hybrids, 0.3HMC2 with introducing FeCl 3 ·6H 2 O (0.3 g) and NCDs (2 mL) presented an optimum adsorption–photocatalysis coupling effects. The photodegradation efficiency over the hybrid was able to reach 100% within 60 min under visible-light irradiation. The excellent performances should be ascribed to good textural properties, π – π interaction formation, fast electron separation nature of NCDs and internal Z-scheme construction between hematite and MIL-101(Cr) phases. Meanwhile, the hybrid 0.3HMC2 showed good stability and reusability for photocatalytic degradation of CBZ. Furthermore, a possible mechanism for the removal of CBZ was also proposed to illustrate the photodegradation process. It is thus clear that the hybrid HMC is a promising catalyst for the removal of CBZ in wastewater.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2024
·
IF 8.2
Huirong Zhang,Yi Shen,Xiaokai Shi,Jinlei Cui,Baofeng Wang,Yanxia Guo,Dongke Zhang,Fangqin Cheng
Persistent environmental pollution by heavy metals, particularly Cr (VI), poses significant risks to ecosystems and human health due to its high toxicity and bioaccumulation potential. The development of high-performance, cost-effective adsorbents from sustainable materials remains a critical challenge in the field of Cr (VI) remediation. This study investigates the influence of pyrrolic-N (N-5) within nitrogen-doped hierarchical porous carbon (N-HPC) on its adsorption capacity. Results indicate that N-HPC variants with a higher N-5 content exhibit superior adsorption abilities. The optimal sample demonstrated an exceptional adsorption capacity of 386.2 mg/g for Cr (VI). Even after seven regeneration cycles, this N-HPC variant maintained a remarkable 77.8 % removal efficiency for Cr (VI), highlighting its robust stability and selectivity. The relationship between the physicochemical properties of N-5 and N-HPC was thoroughly examined, revealing that N-5 plays a crucial role in the adsorption process. Due to its high electronegativity, nitrogen-doping into the carbon framework generates a dipole moment, enhancing the electronegativity of N-HPC, altering its local electron density and polarity, increasing specific surface area, carbon defect density, and ion exchange capacity. These factors collectively contribute to significant improvements in pore filling, ion exchange efficiency, and electrostatic adsorption by N-HPC. The reduction complexation mechanism emerges as the dominant factor in the adsorption process. N-5 not only provides reducing electrons as an electron donor, facilitating the continuous conversion of Cr (VI) to Cr (III), but also acts as an adsorption active site, complexing Cr to the surface of N-HPC. This synergistic effect strengthens the reduction complexation, enhances adsorption performance, and improves the regeneration cycle and adsorption selectivity for Cr.
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高影响因子
ENVIRONMENTAL RESEARCH
·
2025
·
IF 7.7
Xiao-Qian Jin,Jia-Lei Li,Jun-Bin Xiong,Rui Zhang,Chen-Yuan Li,Xue-Ting Wang,Wei-Hong Guo,Da-Chuan Yin
In this work, cross-linked hemoglobin crystals (CLHCs) were synthesized using discarded cow blood as raw material, and palladium nano particles (Pd NPs) was synthesized in situ within its lattice to obtain CLHCs@Pd catalytic used for catalyzing the reduction of Cr(VI). In addition, we investigated the influence of synthesis process on the morphology, loading capacity, and size of Pd NPs, and the results showed that the minimum size of Pd NPs was distributed around 2 nm under any process conditions. The X-ray single crystal diffraction results indicate that the lattice of protein crystals may have a controlling effect on the size of Pd NPs. Subsequently, the mechanism of synthesizing Pd NPs by CLHCs was studied using techniques such as SEM, TEM, FTIR and XPS. Finally, the catalytic activity and cycling performance of Cr(VI) removal by CLHCs@Pd were evaluated. The results indicate that the CLHCs@Pd not only exhibit high catalytic activity for Cr(VI) removal, but also maintain consistent catalytic performance over 20 consecutive catalytic cycles. Overall, this work provides CLHCs@Pd catalysts have the following advantages: (1) small size and uniform dispersion of Pd NPs; (2) High cycling performance and high catalytic activity; (3) Low cost and environmentally friendly preparation process.
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