APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Xian Li,Jiafeng He,Weilong Zhang,Lijun You,Jumei Li
A sandwich structured Fe 3 O 4 /Ag/m(TiO 2 -ZrO 2 ) magnetic nanosphere with Ag nanoparticles as an interim layer was fabricated with in situ deposition of Ag nanoparticles onto Fe 3 O 4 nanospheres and subsequent coating an outmost shell of mesoporous TiO 2 -ZrO 2 . As compared to Fe 3 O 4 /m(TiO 2 -ZrO 2 )/Ag with Ag nanoparticles as the outmost layer, unique Fe 3 O 4 /Ag/m(TiO 2 -ZrO 2 ) sandwich nanospheres possess higher efficient charge migration and larger specific surface area disclosed by the BET and photoelectrochemical characterizations, so they present improved photocatalytic activity toward Cr(VI) reduction. In addition, they have high thermal stability because mesoporous TiO 2 -ZrO 2 outmost shell could protect the interim Ag nanoparticles from damage and agglomeration at high temperature. Results showed reduction efficiency of Cr(VI) of Fe 3 O 4 /Ag/m(TiO 2 -ZrO 2 ) reached 98.4 % in 30 min, as 1.6 times as that of Fe 3 O 4 /m(TiO 2 -ZrO 2 )/Ag. The Fe 3 O 4 /Ag/m(TiO 2 -ZrO 2 ) still obtained 91.3 % and 87.9 % reduction ratio after calcination at 500 ℃ and recycling 5 times, respectively. The photocatalytic mechanism was also revealed by scavenger experiments and ERP analysis. This work provided a good example for further design and preparation of magnetic photocatalysts with high performance for the remediation of heavy metal pollutants.
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Ruoning Chu,Xiaojie Guo,Yongjun Zhang,Xiaoyu Zhao,Xiantao Xiong,Xiujuan Zhang,Fengyi Zhang,Kun Zhang,Yaxin Wang
Water containing heavy metal ions can be extremely harmful to the environment and human body, thus the development of low-cost and high-efficient adsorbents has an exciting prospect. In this study, lignin/graphene aerogels modified with polydopamine and polyethyleneimine , respectively, were successfully prepared to remove Cr(VI) from aqueous waste. The physicochemical properties of graphene aerogels (GA), lignin/graphene aerogels (LGA), polydopamine-modified lignin/graphene aerogels (LGA@PDA), polyethyleneimine-modified lignin/graphene aerogels (LGA@PEI) were investigated using FT-IR, Raman spectroscopy , XRD , XPS , SEM-EDS, and BET analysis. The results demonstrate that adsorbents have a high specific surface area, an interconnected porous structure, and a large number of oxygen-containing groups, making them particularly favorable for heavy metal adsorption. The effects of GO/lignin ratio, surface modifiers, solution pH, contact time, initial concentration and temperature on the Cr(VI) removal were investigated and compared via batch experiments. Compared with GA (138.74 ± 3.93 mg/g), the adsorption capacity of LGA with GO/LA ratio 40:1 increased to 167.66 ± 4.75 mg/g. Furthermore, the maximum adsorption capacity of LGA@PEI and LGA@PDA rose up to 209.85 ± 3.25 mg/g and 240.39 ± 3.26 mg/mg, respectively. By simulating the experimental data with different kinetic models and isotherm models, the adsorption processes of different lignin-derived aerogels were further explored under various conditions. All types of aerogels fit well with the pseudo-second-order model and Langmuir model. In addition, the XPS results confirm that the chemical reduction of Cr(VI) to Cr(III) also plays a role in the removal of Cr(VI). The results demonstrated that the removal effect of lignin-derived aerogels on Cr(VI) was greatly improved through the multi-functionalized surface modification of LGA with PDA and PEI. Furthermore, the removal efficiency of LGA@PDA and LGA@PEI for Cr(VI) remained stable after repeated regeneration. Therefore, the results of this study indicate that LGA@PDA and LGA@PEI are promising Cr(VI) adsorbents for practical applications in wastewater treatment.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Jingjing Xu,Chen Liu,Junfeng Niu,Yanlin Zhu,Biying Zang,Mengjuan Xie,Mindong Chen
LaFeO 3 /Bi 3 NbO 7 p-n heterojunction photocatalysts were prepared successfully through an in-situ growth method. The phase structure, optical property , morphology and microstructures of the obtained samples were studied by X-Ray diffractometer (XRD), Ultraviolet–visible absorption spectrum (UV–vis DRS), photoluminescence (PL) spectroscopy, transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM). The visible light responsive photocatalytic activity of as-obtained samples were investigated by the photo-reduction of Cr (Ⅵ). The effects of preparation conditions (proportion of BNO/LFO and temperature) on the activity were studied. Results showed that the as-obtained BNO-LFO-200-5 composite behaved the best photocatalytic activity (with rate constant of 0.0212 min −1 ) among all the obtained samples. The rate constant was about 42.4-times and 17.7-times as that of pristine BNO (0.0005 min −1 ) and LFO (0.0012 min −1 ), respectively. The enhanced photocatalytic property of the as-prepare LaFeO 3 /Bi 3 NbO 7 composites can be ascribed to the formation of p-n junction between BNO and LFO, which significantly increased the separation efficiency of photo-excited electron-holes.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Shikai Li,Hanbing Gao,Rui Xu,Zhaohui Guo
Cation and oxyanion heavy metals possess opposite physical and chemical properties, which could be hard to simultaneous remediate in soil. In this study, layered double hydroxides from secondary aluminum ash (SAA-LDH) has been synthesized for soil remediation contaminated with heavy metals. The as-obtained SAA-LDH exhibit strong affinity for heavy metals, which could remove 193.50 mg‧g −1 of Cr(Ⅵ) and 175.84 mg‧g −1 of Cd(Ⅱ) within 2 h. Optimum acid-base resistance and selectivity guarantee the practice potential of SAA-LDH, which could remove above 85 % of Cd(Ⅱ) and Cr(Ⅵ) under widely pH range (from 4.00 to 10.00), capturing above 90 % of Cd(Ⅱ) and Cr(Ⅵ) under the interference of seven coexisting ions. Soil remediation tests and column leaching experiments further demonstrate that SAA-LDH could immobilize 98.32 % of Cd(Ⅱ) and 97.71 % of Cr(Ⅵ), preventing its migration. Density functional theory (DFT) manifests that SAA-LDH could remove Cd(Ⅱ) and Cr(Ⅵ) through isomorphic substitution and ion exchange respectively under single system. Under compound system, Cd(Ⅱ) fixed with isomorphic substitution could promote the immobilization of Cr(Ⅵ) onto SAA-LDH, constructing hyper-stable coordination structure. This study provides an effective approach to simultaneously recycle hazardous waste and remediate heavy metals contamination in soil.
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2022
·
IF 7.968
Taotao Qiang,Shaoting Wang,Longfang Ren,Xiaodong Gao
ZIF-8 exhibits poor visible light response and rapid electron-hole recombination. To address these problems, we constructed an N-CQD/ZIF-8 framework by in-situ synthesis method, then prepared a novel Z-scheme heterostructure photocatalyst (Cu 2 O/N-CQD/ZIF-8) by reduction precipitation method for the efficient photocatalytic reduction of Cr(Ⅵ). Cu 2 O/N-CQD/ZIF-8 (with a 10% Cu 2 O loading) had a unique heterostructure and exhibited significantly improved performance for Cr(Ⅵ) photoreduction . This photocatalyst successfully reduced 98.99% of the Cr(Ⅵ) in a pH = 3 solution system, which was 6 times higher than that of ZIF-8. Meantime, due to its stable interfacial adhesion, the reduction efficiency of Cr(Ⅵ) by Cu 2 O/N-CQD/ZIF-8 still reached 97.13% after five cycles. Therefore, Cu 2 O/N-CQD/ZIF-8 exhibited superior photocatalytic activity and recyclability compared with unmodified ZIF-8. The charge transfer path of this Z-scheme heterojunction was verified by free radical trapping experiments and X-ray photoelectron spectroscopy. Moreover, a possible charge transfer mechanism was proposed. N-CQD provided a potential driving force for the construction of the internal Z-scheme charge transfer system. Moreover, the synergistic effect between Cu 2 O and ZIF-8 inhibited the rapid recombination of photogenerated electron-hole pairs. This work provides potential insights for the innovative design of high-performance photocatalysts based on metal-organic frameworks for the restoration of Cr(Ⅵ)-containing wastewater.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Wenqiang Wang,Guanghui Zhang,Lihua Dong,Ping Gu,Shiyuan Ding,Lian Hou
Persistent toxic heavy metal Cr(Ⅵ) oxyanions is increasingly damaging to the environment and human life safety. In this study, a novel tertiary amine chloride type cationic covalent organic framework with high yield (>95%) was synthesized using a one-step Schiff base reaction by room temperature standing two functional monomers . The adsorbent was characterized by SEM, EDS , FTIR , NMR , PXRD , BET, TGA and pH PZC . And a series of adsorption experiments were conducted to verify the removal effect for Cr(Ⅵ). It exhibited excellent adsorption performance and the adsorption equilibrium time was within 10 min, superior to most adsorbents. The adsorption conformed to the pseudo-second-order kinetics and the Langmuir adsorption isothermal models based on the values of R 2 and RMSE in the corresponding four models. The impact of pH was significant, and the maximum adsorption capacity was 161.4 mg/g at a pH of 2. The adsorbent had good adsorption selectivity for Cr(Ⅵ) oxyanions in the presence of coexisting ions (Cl − , SO 4 2− , NO 3 − , and PO 43 − ), and good recyclability with only decrease of removal rate from 98.3% to 91.5% after five cycles. The mechanism for Cr(Ⅵ) adsorption was mainly attributed to ion exchange, and hydrogen bonding also played a subordinate role. In the Cr(Ⅵ)-MO binary system, the increase for Cr(VI) adsorption results from the new active sites in methyl orange. This work highlights the mild synthetic conditions, fast adsorption rate, and good adsorption of Cr(Ⅵ), which make it a promising prospect.
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2022
·
IF 3.752
Xuejing Wang,Juan Xu,Sifan Liu,Wenwen Yang,Yanmei Chen,Yanhui Zhang
The research of metal organic frameworks materials of possessing semiconductor performance is important because they show great prospects on applications in wastewater treatment . In the current work, composites of TiO 2 / MOF-801(Zr) was prepared by a wet impregnation at room temperature , and a series of characterizations for catalysts, such as XRD , TEM , XPS, etc was investigated. The results of photocatalytic reduction of Cr(Ⅵ) under simulated solar light irradiation showed that 50%TiO 2 / MOF-801(Zr) exhibited better photocatalytic activity compared with other catalysts, which is attributed to synergistic effect including the interface enhancement effect and the enhancement of photogenerated carriers separation efficiency. The photocatalytic efficiency is as high as 98.1% when adjusting pH of reaction system to 1. It is most likely because the hydrogen cation concentration increased along with the increasing acidity, so that as to the promoting of reduction process of Cr(Ⅵ). In addition, we proposed a possible reaction mechanism of TiO 2 / MOF-801(Zr) composites for photocatalytic reduction of Cr(Ⅵ).
✓ 已验证
DOI
高影响因子
TALANTA
·
2020
·
IF 5.339
Wei Zou,Chenghui Li,Jing Hu,Xiandeng Hou
A novel and sensitive method for the selective determination of Cr(VI) and non-chromatographic speciation of Cr(VI) and Cr(III) was developed based on chemical vapor generation (CVG) in KBH 4 -acid system for sample introduction into an inductively coupled plasma mass spectrometer (ICP-MS) for detection. The CVG of Cr(VI), rather than Cr(III), was found to be remarkably enhanced in the presence of sodium diethylaminodithioformate (DDTC). After the oxidation of Cr(III) to Cr(VI) by KMnO 4 , the quantitation of Cr(III) could be obtained based on the difference between the concentration of total chromium and that of Cr(VI). Parameters affecting the CVG reaction and determination of Cr(VI) were evaluated in detail, including the concentrations of DDTC, hydrochloric acid and KBH 4 , the sample flow rate , as well as the length of reaction and transferring tubing. Under optimal conditions, the CVG efficiency and the limit of detection (LOD) of Cr(VI) were found to be 28% and 0.2 ng mL −1 , respectively. The relative standard deviations for seven replicate measurements of 20 ng mL −1 of Cr(Ⅵ) was 1.8%. Furthermore, with excess DDTC (100 μg mL −1 ) added to the test solutions, possible interferences from Cu 2+ (up to 400 ng mL −1 ) could be eliminated. The proposed method was thus successfully applied to the determination of Cr(VI) in three real water samples and one certified reference water sample, as well as two simulated water samples of Cr(VI) and Cr(III), all with satisfactory results. The possible reasons were discussed for the varied degrees of enhancement between Cr(III) and Cr(VI).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Fulin Wang,Helin Hua,Hui Jia,Dingying He,Zhongyou Jiang,Jiaxin Cao,Shanshan Dong,Zhenxing Zeng,Suhua Chen
The construction of heterojunction is considered to be an effective way to promote the photocatalytic activity, while it is always challenging due to the mismatched lattices of heterojunctional materials and results in an unsatisfactory enhancement of charge carrier separation. It is critical to overcome that lattice mismatch and establish charge transfer channels in heterojunction for achieving high charge transfer and separation. In this study, a red phosphorus/phosphorus doped graphitic carbon nitride (RP/P-CN) type I heterojunction was constructed to boost interfacial charge transfer for Cr(Ⅵ) photoreduction through in situ growing RP on g-C 3 N 4 nanosheets. The formed P − N bonds around interfaces in the RP/P-CN allowed photoexcited charge to rapidly transfer from the conduction band of P-CN to that of RP, which contributed to the significant achievement of Cr(Ⅵ) reduction. The constructed interfacial charge transfer channels largely promoted the photoexcited charge carrier separation in the RP/P-CN. Additionally, the simultaneous RP formation and P doping significantly enhanced the visible light response and the adsorption efficiency of Cr(Ⅵ). As a result, RP/P-CN 1:5 could achieve 99.1 % removal of Cr(Ⅵ) after 20-min visible light irradiation with an achieved apparent kinetic rate constant (k app ) of 0.2289 min −1 , which were much better than the 19.2 % of Cr(Ⅵ) removal by pure g-C 3 N 4 and presented a 21-fold higher k app than pure g-C 3 N 4 (0.0108 min −1 ) achieved, respectively. This study provides a new strategy to design an efficient g-C 3 N 4 based metal-free heterojunction for Cr(Ⅵ) photoreduction.
✓ 已验证
产品关联
DOI
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2023
·
IF 8.4
Deming Zhao,Yiting Liu,Chunxin Wu
The research on developing a purification technology for Cr(Ⅵ) polluted water with high efficiency and the low energy consumption is crucial for achieving several Sustainable Development Goals (SDGs). In order to achieve these goals, Fe 3 O 4 @SiO 2 -APTMS nanocomposites were prepared by Fe 3 O 4 nanoparticles modified with silica and 3-aminopropyltrimethoxysilane in the presence of ultrasonic irradiation. The nanocomposites were characterized by TEM, FT-IR, VSM, TGA, BET, XRD, XPS and these analytic results proved that the nanocomposites were successfully prepared. The influential factors of Fe 3 O 4 @SiO 2 -APTMS on Cr(Ⅵ) adsorption have been explored and better experimental conditions have been obtained. The adsorption isotherm conformed to the Freundlich model. Pseudo-second-order kinetic model provided a better correlation for the experimental data compared to other kinetic models. Thermodynamic parameters for adsorption indicated that the adsorption of Cr(Ⅵ) was a spontaneous process. It was speculated that the adsorption mechanism of this adsorbent includes redox, electrostatic adsorption and physical adsorption. In summary, the Fe 3 O 4 @SiO 2 -APTMS nanocomposites were of great significance to human health and the remediation of heavy ion pollution, contributing to achievement of the Sustainable Development Goals (SDGs), including SDG-3, SDG-6.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yi Wen,Zheng Huang,Min Zhao,Longshan Zhao
The discharge of industrial heavy metal wastewater not only leads to environmental pollution, but also harms human health, so it is imperative to control heavy metal pollution. In the current work, a sequence of anatase/brookite TiO 2 @COF with different mass ratios, bi-phase TiO 2 and bare COF were successfully synthesized by simple hydrothermal synthesis. The photocatalytic activity of the prepared catalysts was assessed by reducing Cr(Ⅵ) in model pollutant (K 2 Cr 2 O 7 ). Under the condition of pH = 3, the Cr(Ⅵ) reduction rate of TiO 2 @COF-4 was as high as 99.19% in 30 min. The photocatalytic activity of TiO 2 @COF-4 remained stable in four consecutive cycles, suggesting that it has a potential application prospect for the removal of Cr(Ⅵ) in the actual environment. The morphology and structure of photocatalysts were observed by different techniques (SEM/EDS, HRTEM, BET analysis, XRD, FTIR and XPS). The specific reasons for the enhancement of photocatalytic performance of materials were explored by different methods (PL, UV–vis DRS, Mott-Schottky plots, I-T curves and EIS). Finally, we concluded that the photocatalytic system of TiO 2 @COF-4 may follow the typical direct Z- scheme mechanism. This work provides an effective solution for the water treatment of heavy metal pollution.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL RESEARCH
·
2024
·
IF 7.7
Wenfei Ding,Zhaoyi Mo,Jia Qi,Mengying Wang,Junyu Zou,Kuo Wang,Daxiang Gong,Yongju Zhao,Hong Miao,Zhongquan Zhao
Cr(Ⅵ) residues in livestock and poultry wastewater are a rising concern for human health and biotic environments. For the removal of Cr(Ⅵ), its simultaneous reduction and adsorption represents a sustainable and efficient strategy. Herein, iron nodes on covalently bonded two-dimensional phthalocyanine organic polymer (PcOP-Fe) nanosheets with space-separated dual-active sites are developed for the simultaneous detection and removal of Cr(VI) from wastewater. In the FeN 4 structure of PcOP-Fe nanosheets, Fe acts as an electron capture center, effectively facilitating the accumulation of photogenerated electrons and transferring them to Cr(VI), thereby achieving its photocatalytic reduction. Meanwhile, pyrrolic nitrogen provides excellent adsorption sites, enabling the adsorption of Cr(III) or Cr(0). Fe accumulates the photogenerated electrons from pyrrole N and transfer them to Cr(Ⅵ). The formation of N-Cr(Ⅲ) bonds causes a space-separation between Cr(Ⅵ) and Cr(III). In addition, PcOP-Fe can be used for a Cr(Ⅵ) detection agent. The photoluminescence intensity decreases linearly with increasing Cr(Ⅵ) concentration from 80 μM to 2 mM, with a limit of detection of 0.18 μM. The PcOP-Fe nanosheets exhibit good Cr(Ⅵ) detection and reduction performance in livestock and poultry wastewater, suggesting their suitability for practical sensing applications. Thus, the PcOP-Fe nanosheets with space-separated dual-active sites are promising for the simultaneous detection and removal of Cr(Ⅵ) in water treatment processes.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）