Journal of Materials Chemistry A
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2018
·Vol. 6
·期 45
·22580-22589
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IF 9.931
Xiu-Qing Qiao,Zhen-Wei Zhang,Qiu-Hao Li,Dongfang Hou,Qichun Zhang,Jian Zhang,Dong-Sheng Li,Pingyun Feng,Xianhui Bu
Exploiting novel photocatalysts with high efficiency and durability for reduction of hexavalent chromium (Cr(VI)) has gained attention from fundamental science and industrial research. In this work, we synthesized novel two-dimensional (2D) n–n Bi2MoO6 & Bi2S3 heterojunctions by a facile in situ anion exchange process for remarkably efficient removal of Cr(VI). Results show that Bi2MoO6 & Bi2S3 heterojunctions with core–shell structures are formed through the intimate contact of Bi2MoO6 core and Bi2S3 shell. The prepared Bi2MoO6 & Bi2S3 heterojunctions exhibit unprecedented photocatalytic activity for reduction of Cr(VI) under visible light irradiation. The optimized BMO-S1 heterojunction displays the highest reduction efficiency (κapp = 0.164 min−1) for Cr(VI) reduction. To the best of our knowledge, it is one of the highest reduction rate achieved among reported photocatalysts for Cr(VI) reduction under visible-light irradiation. Detailed studies show that strong selective adsorption for Cr(VI) enhances this unprecedented photocatalytic activity. Moreover, the intimate heterojunction between Bi2MoO6 core and Bi2S3 shell can efficiently deteriorate the charge carrier recombination and Bi2S3 content can boost visible light harvesting, thereby contributing to the remarkable photocatalytic catalytic activity, which were proven by PL, EIS and transient photocurrent responses. Characterization of Mott–Schottky plots and DRS prove that the Bi2MoO6 & Bi2S3 heterojunctions established a type-II band alignment with intimate contact, accounting for the efficient transfer and separation of photogenerated carriers. This work provides a simple route for facial synthesis of heterojunction photocatalysts for Cr(VI) reduction in industrial applications.
研究领域:
材料科学
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环境科学
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化学
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DOI
高影响因子
Green Processing and Synthesis
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2025
·Vol. 14
·期 1
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IF 3
Fuhua Wei,Yan Wang,Qinhui Ren,Qin Zhang,Hongliang Chen,Zhao Liang
Cr/Co-MOFs were synthesized via a solvothermal method using chromium acetate and cobalt chloride hexahydrate as metal ions, and trimeric acid as the organic ligand. The structures of Cr/Co-MOFs were characterized using Fourier infrared spectroscopy, X-ray diffraction, and scanning electron microscopy techniques. These Cr/Co-MOFs were used for removing organic contaminants in wastewater treatment. Fleroxacin and Rhodamine B (RhB) were specifically selected as target molecules in this study to evaluate the removal efficiency based on the mass of Co/Cr-MOFs, concentrations of organic contaminants, and adsorption time. Experimental findings indicated that at a Co/Cr-MOFs dosage of 100 mg, with initial concentrations of Fleroxacin (30 ppm) and RhB (20 ppm), removal efficiencies achieved were 95% and 99%, respectively. Within a timeframe of 5 h, Co/Cr-MOFs attained adsorption capacities amounting to 269.6 mg·g −1 for fleroxacin and 289.5 mg·g −1 for RhB. The interaction between Co/Cr-MOFs and fleroxacin, as well as RhB, is primarily attributed to factors such as pore size, hydrogen bonding, electrostatic charge, and π–π interactions. Moreover, theoretical analysis corroborated these experimental results by demonstrating conformity between the adsorption process and both second-order kinetic model equations alongside Langmuir isotherm model equations. Collectively, the experimental data combined with theoretical investigations underscore the practical significance associated with employing Co/Cr-MOFs for effective eradication of organic pollutants.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
MICROCHEMICAL JOURNAL
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2024
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IF 4.9
Zhichang Ma,Jing Sun,Hemeiling Cai,Junwei Di
A photoelectrochemical (PEC) sensor based on a BiVO 4 semiconductor and gold nanoparticles (AuNPs) was successfully prepared for the sensitive detection of Cr(Ⅵ) ions. The calcination temperature was found to be very important for the PEC properties of BiVO 4 . The BiVO 4 -modified indium tin oxide electrode (ITO/BiVO 4 ) calcined at 300 °C generated a low cathodic photocurrent response under light irradiation. BiVO 4 /AuNPs materials were coupled via electrostatic adsorption to enhance the photoelectric conversion performance of BiVO 4 . The use of self-assembled monolayers (SAMs) to modify electrodes reduce the background current. The developed ITO/BiVO 4 /AuNPs/L-Cys PEC sensor was used to detect of Cr(VI). The Cr(Ⅵ) ion concentrations showed a good linearity between 10 pM and 1 μM with a detection limit of 9.1 pM (S/N = 3). The prepared PEC sensor exhibited high sensitivity, a wide linear range, and good selectivity. This work provides a promising platform for the analytical detection of heavy metal ions.
研究领域:
环境科学
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分析化学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
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IF 11.698
Xue Bai,Yanyan Du,Xiaoyun Hu,Yudong He,Chunliang He,Enzhou Liu,Jun Fan
A novel RP-MoS 2 /rGO nanocomposite as low-cost, environmental sustanable, stability and high-performance photocatalyst was successfully fabricated for the first time through a facile two-step hydrothermal method. Even without a noble-metal cocatalyst, the introduction of MoS 2 /rGO hybrid made RP exhibit excellent photocatalytic performance, including photoreduction of Cr (VI) and photooxidation of different organic pollutants, owing to the increased number of excited electrons/holes and enhanced separation efficiency of charge carriers. Importantly, the synergy of photocatalytic reduction and oxidation, as well as photocatalysis and adsorption played an important role in enhancing photocatalytic activity and reaching a high efficiency. Besides, the chemical structure of the RP-MoS 2 /rGO with P–S and P O bands ensure the stability of the nanocomposite materials. Overall, the photocatalytic elimination of the Cr (VI)-Organic molecule coexistence system in this work shows promising application to treatment the reality wastewater.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
Journal of Materials Chemistry A
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2015
·Vol. 3
·期 12
·6586-6591
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IF 7.443
Hongfei Shi,Huaqiao Tan,Wan-bin Zhu,Zaicheng Sun,Yuejia Ma,Enbo Wang
A series of Cr-doped Bi4Ti3O12/Bi2Ti2O7 (BTO) heterostructure fibers have been synthesized via a one-step, facile and economical electrospinning/calcination process. SEM and TEM results reveal that the diameters of the as-prepared fibers are 100 ± 30 nm. The light adsorption of Bi4Ti3O12 and Bi2Ti2O7 in the fibers has been remarkably improved by Cr doping. With increased Cr doping, XRD and XPS show that the amount of Bi2Ti2O7 increases in the fibers. As a result, the Bi4Ti3O12/Bi2Ti2O7 heterojunction structure is enhanced, which further promotes the charge separation of photogenerated charge carriers. Photocatalytic tests indicated that the as-prepared Cr-doped Bi4Ti3O12/Bi2Ti2O7 fibers exhibit good photocatalytic activity for photodegradation of methyl orange (MO) under visible-light irradiation.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Materials
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2021
·Vol. 14
·期 19
·5598
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IF 3.623
Huajiang Zhou,Shaozhao Wang,Daowen Wu,Qiang Chen,Yu Chen
In this work, a kind of Gd/Cr codoped Bi3TiNbO9Aurivillius phase ceramic with the formula of Bi2.8Gd0.2TiNbO9+ 0.2 wt% Cr2O3(abbreviated as BGTN−0.2Cr) was prepared by a conventional solid-state reaction route. Microstructures and electrical conduction behaviors of the ceramic were investigated. XRD and SEM detection found that the BGTN−0.2Cr ceramic was crystallized in a pure Bi3TiNbO9phase and composed of plate-like grains. A uniform element distribution involving Bi, Gd, Ti, Nb, Cr, and O was identified in the ceramic by EDS. Because of the frequency dependence of the conductivity between 300 and 650 °C, the electrical conduction mechanisms of the BGTN−0.2Cr ceramic were attributed to the jump of the charge carriers. Based on the correlated barrier hopping (CBH) model, the maximum barrier heightWM, dc conduction activation energyEc, and hopping conduction activation energyEpwere calculated with values of 0.63 eV, 1.09 eV, and 0.73 eV, respectively. Impedance spectrum analysis revealed that the contribution of grains to the conductance increased with rise in temperature; at high temperatures, the conductance behavior of grains deviated from the Debye relaxation model more than that of grain boundaries. Calculation of electrical modulus further suggested that the degree of interaction between charge carriersβtended to grow larger with rising temperature. In view of the approximate relaxation activation energy (~1 eV) calculated fromZ″andM″ peaks, the dielectric relaxation process of the BGTN−0.2Cr ceramic was suggested to be dominated by the thermally activated motion of oxygen vacancies as defect charge carriers. Finally, a high piezoelectricity ofd33= 18 pC/N as well as a high resistivity ofρdc= 1.52 × 105Ω cm at 600 °C provided the BGTN−0.2Cr ceramic with promising applications in the piezoelectric sensors with operating temperature above 600 °C.Keywords:Aurivillius phase ceramic;Bi3TiNbO9;electrical conduction behaviors;impedance spectrum;electrical modulus
研究领域:
材料科学
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电子工程
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DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
Yuan Tang,Xiaohong Yin,Manman Mu,Yue Jiang,Xiaoli Li,Hao Zhang,Tianwei Ouyang
A series of anatase TiO 2 @MIL-101(Cr) was synthesized using the solvothermal method for photocatalytic degradation of bisphenol A (BPA). The characterization of the composites showed that they had an octahedral shape that was similar to that of MIL-101(Cr), but the particle size was reduced to about 300–500 nm. The amount and surface area of the TiO 2 in the composites jointly influenced the photocatalytic degradation; in optimal conditions, 59 % TiO 2 @MIL-101(Cr) could achieve 99.4 % BPA degradation in 240 min under UV irradiation. This superior photocatalytic performance was the result of the effective separation of electron-hole pairs and a narrow band gap. Moreover, the optimal composite exhibited excellent stability, indicating its suitability for reuse. Reasonable pathways of BPA degradation were proposed based on the detected intermediates during the degradation, where the oxidative radical O 2 − played a dominant role.
研究领域:
环境科学
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材料科学
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高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Peng Liu,Xiaowei Wu,Suyi Pan,Jiamin Dai,Zixuan Zhang,Xuetao Guo
Wastewater treatment plants (WWTPs) are the important source of microplastics (MPs) in the environment, and disinfection processes bear high potential to degrade MPs. This study investigated the physicochemical degradation, dissolved organic products and interaction with co-existed pollutants (heavy metal and pharmaceutical) on polyethylene (PE), polypropylene (PP) and polystyrene (PS) MPs during simulated disinfection processes. Compared to photo or chlorination, photochlorination significantly resulted in the physicochemical degradation, including morphology alteration, fragmentation, and chemical oxidation on PP and PS MPs, but showed relatively low effect on PE, indicating the different resistance among polymers to disinfected treatment. Photochlorination also caused the formation of chain-scission organic compounds and even chlorinated products from MPs (e.g. C 11 H 19 O 4 Cl for PP and monochlorophenol, dichlorophenol, chloroacetophenone and chlorobenzoic acid for PS), which may form disinfection byproducts to induce healthy risk. The adsorption potentials of MPs for Cr(VI) or amlodipine were enhanced by photochlorination since the cracking and formed oxygen functional groups enhanced the pore filling and surface precipitation of Cr(VI), and the electrostatic attraction and hydrogen bonding with amlodipine. The findings indicated the physicochemical degradation of MPs and the combined pollution with co-existed pollutants, highlighting the health risks of MP-derived organic products during the disinfection treatments (even in normal dosage) in WWTPs.
研究领域:
环境科学
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毒理学
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DOI
PubMed
高影响因子
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
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2022
·Vol. 110
·期 1
·1-7
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IF 2.807
Gu Xinfeng,Mo Huijing,Wang Lei,Zhang Lianyi,Ding Zhuhong
Transport of Cr(VI) at the presence of bentonite colloid was carried out in saturated porous media of 16–18 mesh and 40–60 mesh sand columns. Effects of flow rate, pH, ion strength, humic acid and bentonite concentrations on Cr(VI) migration were investigated. The results show that the increase of flow rate accelerated the breakthrough of Cr(VI) and BP, but the transport mass of dissolved Cr(VI) decreased by ~ 15.0% when flow rate increased to 2.5 ml min −1 . Increasing IS to 10mM resulted in decrease of Cr(VI) transport mass by 6.86%–21.4%. Increase of pH and decrease of bentonite concentration favored the transport of dissolved Cr(VI). Humic acid had little effect on transport amount of Cr at pH7. Cr(VI) transport was dominated by the dissolved Cr(VI). The transport data of dissolved Cr(VI) were well described by the two-site model. The presence of BP reduced total Cr(VI) transport mass in co-transport.
研究领域:
环境科学
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土壤学
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PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2021
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IF 5.876
Anqi Sun,Ying Wu,Zhenjiang He,Peng Bai,Jiafei Lyu,Xianghai Guo
The flexible metal-organic framework MIL-53(Cr) has been demonstrated to be an efficient adsorbent for liquid phase adsorption and separation, while the effect of this attractive “breathing effect” on its performance remains uncertain. In this research, by increasing the amount of introduced water, MIL-53(Cr) first shrank into a narrow pore form through bound water and then reopened due to the introduction of free water. Using MIL-53(Cr) with diverse amounts of water as an adsorbent, the liquid-phase adsorption and separation of C8 aromatics, including o -xylene (OX), p -xylene (PX), m -xylene (MX) and ethylbenzene (EB), was manipulated by the pre-adsorbed water in MIL-53(Cr). Pre-adsorbing water in MIL-53(Cr) induced a preference reversal between MX and PX, where dry samples preferentially adsorbed MX, while high-water-addition samples preferred PX instead. In addition, the reopened MIL-53(Cr) with high water addition hardly adsorbed EB, thereby increasing the selectivity of xylene isomers to EB. A longer equilibrium time was observed on MIL-53(Cr) with high water addition, during which the adsorption preference shifted from OX to MX to PX. Further molecular simulation provided a microscopic explanation that water molecules in the pores tended to package around MX and EB, hindering their interaction with frameworks or other adsorbates.
研究领域:
化学工程
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材料科学
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高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2021
·Vol. 138
·期 27
·50642
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IF 3.125
Zhimei Wei,Shouyu Zhang,Xiaojun Wang,Shengru Long,Jie Yang
Cr (VI) is a highly toxic pollutant to humans, to achieve high adsorption capacity, easy recovery, and good reusability, polyethersulfone/polydopamine (PES/PDA) ultrafine fibers were prepared successfully. A series of preparing effect factors were investigated systematically and the optimum one is 8.5 pH value at room temperature and 2 g/L dopamine concentration. And then they were used as an adsorbent for the removal of Cr (VI) ions from wastewater. The effect factors pH, the adsorbent dosage, and time were discussed on Cr (VI) adsorption process and the Cr (VI) adsorption behavior was investigated. It is found that the maximum Cr (VI) adsorption capacity is 115.2 ± 4.8 mg/g at pH = 3 using 0.06 g PES/PDA with 80 mins. The Cr (VI) adsorption process followed the pseudo-second-order model (r 2 ≥ 0.99) and adsorption isotherms were fitted to the Langmuir model (R 2 ≥ 0.999). Furthermore, the Cr (VI) adsorption mechanism was supposed according to the X-ray photoelectron spectroscopic results. Finally, PES/PDA ultrafine fibers were considered to be a promising adsorbent with good stability (decomposing temperature, 356°C), high adsorption efficiency (112.1 ± 2.5 mg/g), and good reusability (three times) on the coexistence of anions and the actual industry wastewater environment.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
E-POLYMERS
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2023
·Vol. 23
·期 1
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IF 3.7
Xiaoyu Jie,Bing-Chiuan Shiu,Huazhong Wu,Yuchi Zhang,Yuansong Ye,Chunxiang Lin,Run Fang
Chitosan (CS) is widely used in the treatment of wastewater containing metal ions. However, the poor stability in acidic aqueous solutions severely limits its application in many practical scenarios. In this work, a CS-based composite nanofiber membrane was prepared by electrospinning using urushiol, a natural biomaterial, as the cross-linking agent. The application of the CS-urushiol (CS-U) membrane in the adsorption and recovery of Cr( vi ) in wastewater was systematically studied. The CS-U membrane showed great resistance to strongly acidic and oxidative environments, and the adsorption process combined two mechanisms of electrostatic attraction and redox reaction. Due to the nanoscale fibers, porous structure, and strong acid resistance, the CS-U membrane adsorbed Cr( vi ) rapidly and efficiently in both batch and continuous modes. Moreover, the adsorption capacity and selectivity of the CS-U membrane for Cr( vi ) could be maximized simultaneously by adjusting the solution pH, promoting the recovery of high-purity Cr 2 O 3 .
研究领域:
环境科学
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材料科学
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DOI
高影响因子
危险品化学品经营许可证（带存储）