JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2022
·Vol. 53
·期 5
·935-948
·
IF 2.925
Zhang Xinyi,Fang Qing,Wang Jinjie,Yang Jingxia
The hexavalent chromium waste solution after photocatalysis treatment was reused for surface passivation of low carbon steel (sample p-HCC ), to improve its corrosion resistance. The structure and the anticorrosion properties of p-HCC were confirmed by SEM, XPS, electrochemical impedance spectroscopy. Compared with passivation samples treated by pure Cr(III) solution (sample TCC ), the polarization resistance of p-HCC film (2994 Ω cm 2 ) was larger than that of TCC (2043 Ω cm 2 ), which may be due to the higher Cr content in p-HCC film ( p-HCC : 0.71 atom%, TCC : 0.13 atom%), which was caused by a better interaction between Fe ions and Cr-compound due to Cr(VI) residue and photocatalyst in the photocatalysis reduction for hexavalent chromium.
Graphical abstract
✓ 已验证
产品关联
DOI
高影响因子
Biosensors-Basel
·
2022
·Vol. 12
·期 10
·813
·
IF 5.743
Chao Hu,Ping Pan,Haiping Huang,Hongtao Liu
Cr-MOF nanoparticles were synthesized by a simple hydrothermal method, and their morphology and structure were characterized by SEM, TEM, and XRD techniques. The Cr-MOF modified glassy carbon electrode (Cr-MOF/GCE) was well constructed and served as an efficient electrochemical sensor for the detection of p-nitrophenol (p-NP). It was found that the Cr-MOF nanoparticles had significant electrocatalytic activity toward the reduction of p-NP. The Cr-MOF-based electrochemical sensor exhibited a low detection limit of 0.7 μM for p-NP in a wide range of 2~500 μM and could maintain excellent detection stability in a series of interfering media. The electrochemical sensor was also practically applied to detect p-NP in a local river and confirmed its validity, showing potential application prospects.Keywords:nanoparticle;modified electrode;electrochemical sensor;electrocatalytic activity;detection limit
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Cheng Yu,Lu Yu,Abdelkader Mohamed,Jun Fang,Yichao Wu,Ke Dai,Peng Cai,Qiaoyun Huang
Light irradiation would affect the electron transfer between dissimilatory metal-reducing bacteria (DMRB) and semiconducting minerals, which may impose a great influence on the biogeochemistry cycle of heavy metals. However, the size effect of semiconducting minerals on the its electron transfer with DMRB and microbial Cr(VI) reduction under visible light irradiation is little known. Herein, the Cr(VI) reduction by Shewanella oneidensis MR-1 (MR-1) was investigated in the presence of hematite nanoparticles with average diameters of 10 nm and 50 nm in dark and under visible light irradiation. It is found that hematite nanoparticles adhered onto MR-1 cells to form the composites, leading to the decrease in surface sites and Zeta potential . Hematite mediated-Cr(VI) bioreduction rate under visible light irradiation was 0.342 h −1 , which is 3.4 folds enhancement compared with that in dark and 4.4 folds compared with the MR-1 alone under visible light irradiation. Decreasing nanoparticle size of hematite from 50 nm to 10 nm promoted the Cr(VI) reduction under visible light irradiation but impeded it in dark. It was deduced that the bioelectrons from MR-1 could promote the separation of photoelectron-hole pairs of light-irradiated hematite, which consequently enhanced the Cr(VI) bioreduction by MR-1-hematite composites. Moreover, mutant strains experiments demonstrated the vital role of c -cytochrome for the conducting network actively established by MR-1 with hematite nanoparticles. Those findings expand the understanding of the electron transfer pathway for enhancing Cr(VI) reduction by hematite-MR-1 composites, and the impact of particle size on the interaction between semiconducting mineral and electroactive bacteria under light irradiation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2022
·
IF 8.943
Xiaofeng Jiang,Wenjun Long,Liangqiong Peng,Teng Xu,Faming He,Yuling Tang,Wenhua Zhang
The rapid reductive immobilization of Cr(VI) from the aqueous solution was achieved by reduction to Cr(III) using tannic acid (TA), and subsequent pH-triggering precipitation of the organo-Cr(III) complexes formed in the redox reaction. The effects of TA concentration, temperature, and solution pH on the reduction of Cr(VI) were examined by batch experiments, and the rapid redox reduction followed a second-order kinetics with respect to Cr(VI) concentration in the pH range of 2.0–3.0. UV–visible spectra, FTIR, and XPS confirmed the complete detoxification of Cr(VI) concomitant with carboxylation of partial phenolic hydroxyls in TA. Synchronously, the reduced Cr(III) coordinated with carboxyl groups in oxidized TA (OTA) to form complexes, which exhibited remarkable pH-dependent size distribution characteristics as illustrated by SEM images and sequential filtration/ultrafiltration. The resulted Cr(III) complexes could aggregate into colloids with larger size and precipitate out at pH range of 6.0–8.0 via cross-linking, thereby leading to 93% Cr and 89% TOC immobilization. An eco-friendly and cost-effective method for Cr(VI) elimination and immobilization is provided because polyphenols are natural polymers derived from plants.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2022
·
IF 5.477
Dongmei Jia,Zhaojing Jing,Yongzheng Duan,Jing Li
ABSTRACT Background Hexavalent chromium (Cr(VI)) is a highly hazardous substance due to its carcinogenicity, mutagenicity, genotoxicity, and bioaccumulation through food chains. Therefore, how to remove Cr(VI) fastly is an important issue. Method Polyamine modified carbon nanotubes (PA-CNTs) were synthesized by leveraging a facile grafting condensation modification strategy to remove aqueous Cr(VI). The PA-CNTs was characterized by FTIR, XPS, TGA, SEM and TEM, respectively. The adsorption and desorption behavior of PA-CNTs to Cr(VI) was studied. Significant findings The PA-CNTs showed an extremely fast Cr(VI) adsorption rate with 95% of Cr(VI) was removed within 3 min. In addition, the prepared PA-CNTs adsorbents displayed a maximum Cr(VI) adsorption capacity of 168.54 mg g −1 , benefiting from the newly introduced surface amine groups. The adsorption process is well described by the pseudo-second-order model. Significantly, the synthesized PA-CNTs adsorbents had a high Cr(VI) adsorption capacity of 392.78 mg g −1 in the presence of Rhodamine B, along with an excellent reusability. The enhanced Cr(VI) adsorption performance can be attributed to the strong electrostatic interactions, complexation, as well as oxidation–reduction between Cr(VI) and PA-CNTs.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2023
·
IF 7.7
Guangchao Sun,Jiayu Zhang,Xiang Li,Bianlei Hao,Fatang Xu,Kaiqi Liu
The efficient removal of Cr(VI) in water with high solubility and mobility is of great significance because Cr(VI) is one of the most toxic heavy metals, but it also faces some major challenges. The dispersibility and recyclability of nanoadsorbents are closely related to their Cr(VI) removal efficiency. Herein, the self-assembly method was used to synthesize core-shell hybrid nanoparticles , named Fe 3 O 4 @LDH, with a vertically aligned layered double hydroxide (MgAl-LDH) nanosheet shell and a Fe 3 O 4 magnetite core. The obtained Fe 3 O 4 @LDH nanoparticles exhibit a highly porous and well-ordered three-dimensional core-shell structure with a wool-ball-like morphology. The self-assembled morphology of the core-shell structure can be effectively controlled and induced by regulating the Mg 2+ /Al 3+ ratio of the reaction system. The influence mechanism of charge density of LDH brucite-like layers on the self-assembled morphology was proposed. Fe 3 O 4 @LDH nanoparticles exhibit a Cr(VI) adsorption capacity of 108.7 mg/g. The synergetic contribution of the hybrid self-assembly of Fe 3 O 4 and MgAl-LDH leads to more dispersion, better adsorption capability, and faster kinetics. Moreover, because of the super-paramagnetic and highly saturated magnetization (34.53 emu/g) of the Fe 3 O 4 @LDH nanoparticles, they can be used as efficient magnetic adsorbents and easily separated using a magnetic field and reused. The prepared Fe 3 O 4 @LDH nanoparticles are a cost-effective nanoadsorbent for removing Cr(VI) from wastewater and provide a reference for the structural design and construction of nanocomposites .
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2023
·Vol. 16
·期 22
·7154
·
IF 3.4
Minggang Zhao,Yichang He,Xiaotong Dong,Kun Pang,Qian He,Ye Ma,Hongzhi Cui
Detecting heavy metals in seawater is challenging due to the high salinity and complex composition, which cause strong interference. To address this issue, we propose using a multistage energy barrier as an electrochemical driver to generate electrochemical responses that can resist interference. The Ni-based heterojunction foams with different types of barriers were fabricated to detect Cr(VI), and the effects of the energy barriers on the electrochemical response were studied. The single-stage barrier can effectively drive the electrochemical response, and the multistage barrier is even more powerful in improving sensing performance. A prototype Ni/NiO/CeO2/Au/PANI foam with multistage barriers achieved a high sensitivity and recovery rate (93.63–104.79%) in detecting seawater while resisting interference. The use of multistage barriers as a driver to resist electrochemical interference is a promising approach.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Ming Li,Jianhao Qiu,Lvye Yang,Yi Feng,Jianfeng Yao
Various TiO 2 /ZnIn 2 S 4 composites with an embedded structure have been developed by a facile one-pot synthesis. The activities of all samples were estimated by photocatalytic reduction of Cr(VI) under visible light (λ>420 nm). Results showed that the electrostatic interaction and self-assembly effect make TiO 2 nanoparticles inserting into ZnIn 2 S 4 nanosheets. The resulting TiO 2 /ZnIn 2 S 4 composites show much better photocatalytic performance for Cr(VI) reduction than that of pristine TiO 2 and ZnIn 2 S 4 . Especially, the photocatalytic efficiency of T/ZIS-0.3 (TiO 2 loading of 30 wt%) is approximate 3 times as high as that of pristine ZnIn 2 S 4 (TiO 2 exhibited almost no activity). The embedded structure of TiO 2 /ZnIn 2 S 4 offers apparent increase of specific surface area, visible-light absorption and electrons transfer efficiency, which are responsible for the boosted photocatalytic activity. This work would inspire researchers to construct high-efficiency semiconductor composites for photocatalytic environmental governance.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 84
·44322-44326
·
IF 3.708
Duoying Zhang,Xu Li,Huaqiao Tan,Guoqiang Zhang,Zhao Zhao,Hongfei Shi,Lingtong Zhang,Weixing Yu,Zaicheng Sun
Polyoxometalates (Ti0.75PW12O40, Ti-PTA)/TiO2 nanofiber composites were fabricated by a simple electrospinning technique and then high temperature calcination. In the structure, Ti-PTA, as an electron relay, can accept the photo-generated electrons from the conduction band of TiO2, which promote the separation of photo-generated charges in TiO2. Then the electrons stored on Ti-PTA further transfer to the Cr(VI) in the solution to realize the removal of Cr(VI). The Ti-PTA/TiO2 nanofiber composites exhibit enhanced photocatalytic performance for photocatalytic reduction of Cr(VI), which might be a potential photocatalyst for Cr(VI) removal in environmental therapy.
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2024
·
IF 5.8
Chaorong Chen,Haiyang Xian,Jing Liu,Qingze Chen,Xiaoliang Liang,Runliang Zhu,Michael F. Hochella
Photochemical and adsorptive reactions occurring at the mineral–water interface are of great importance in controlling the fate and transport of contaminants in nature, but the effects of the mineral surface structure on the interplay of these two processes and the underlying mechanisms remain largely unknown. In this work, two different structurally well-defined hematite nanocrystals were employed to explore the coupled photoreduction and immobilization of Cr(VI) on various facets of hematite under light irradiation. Compared with hematite quasi-nanocubes (HNCs) exposing only {012} facets, hematite nanoplates (HNPs) with exposed {001} and {113} facets exhibited higher immobilization ability for Cr(VI) under light irradiation, indicating that the coupled process of photoreduction and adsorption of Cr(VI) strongly relied on the particularly exposed facets of hematite. X-ray photoelectron spectroscopy measurements indicated that the removed Cr(VI) from solution was mainly immobilized on hematite surfaces in the form of Cr(III) (the reduced products of Cr(VI)). Transmission electron microscopy and electron energy-loss spectroscopy results revealed that the accumulation of Cr species was predominantly on the {113} facets of HNPs and the {012} facets of HNCs. Theoretical calculations show that the work function difference between the {113} and {001} facets was directly linked with the effective separation of photogenerated electron–hole pairs in HNPs, which is beneficial for the reduction of Cr(VI). The results of desorption experiments indicate that the coupling of photoreduction and adsorption processes significantly promotes the long-term immobilization of Cr species and effectively reduces their environmental risks (the desorption of Cr(VI) from the HNP and HNC samples decreased from 35.9% and 33.5% to 0.3% and 1.7%, respectively). Overall, the exposed facets can significantly affect the electron transfer properties of hematite as well as the binding affinity for Cr species, thereby governing the reduction and immobilization behavior of Cr(VI) on various facets of hematite. These results advance our understanding of the speciation and immobilization of redox-sensitive contaminants at the surfaces of semiconducting minerals in nature.
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Nano
·
2024
·
IF 5.8
Shengnan Zhang,Lingyi Li,Junxue Li,Wei Cheng
Hematite displays diverse crystal structures and often coexists with Fe(II), both of which are crucial in controlling the fate and mobility of Cr(VI). However, the mechanisms underlying Cr(VI) removal in the presence of Fe(II) on various hematite facets remain elusive. This study aims to elucidate the facet-dependent reactivity of hematite nanocrystals in conjunction with Fe(II) for the removal of Cr(VI) from aqueous solutions. Hematite nanoplates (HNPs), predominantly composed of {001} facets, and nanorods (HNRs), exposing both {001} and {110} facets, were synthesized and characterized. Their Cr(VI) removal capabilities were evaluated in hematite–Cr(VI) and hematite–Fe(II)–Cr(VI) systems, as well as the Fe(II)–Cr(VI) system. The adsorption of Fe(II) and Cr(VI) on hematite surfaces was highly dependent on the crystal facets and pH, with HNRs demonstrating superior Cr(VI) adsorption over HNPs, especially under acidic conditions. Neutral pH favored Fe(II)–Cr(VI) redox reactions and Fe(II) adsorption. The hematite–Fe(II) couple displayed a synergistic effect in removing Cr(VI) under acidic conditions, which was not observed under neutral conditions. The presence of Fe(II) notably enhanced Cr(VI) adsorption onto hematite, and bound Fe(II) facilitated electron transfer, accelerating Cr(VI) reduction. HNRs–Fe(II) exhibited higher Cr(VI) removal efficiency than HNPs–Fe(II) due to their lower free corrosion potential and improved electron transport properties. This research underscores the potential of facet engineering in optimizing hematite nanocrystals for environmental remediation, specifically in Cr(VI)-contaminated environments.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Jianle Wang,Huiqun Zhang,Xiaoyao Wang,Xueming Liu,Hong Deng
Soil washing is employed to prevent the issue of Cr re-oxidation following the remediation of Cr-contaminated soil by transferring contaminants from the soil to the wash solution through the dissolving action. Nevertheless, rapidly screening effective washing agents remains challenging. This study conducted batch experiments to gather dataset on key factors (soil properties, Cr sequential extraction and type of washing agent) and Cr content after washing with 250 experimental data points. We developed 12 machine learning models, among which the light gradient boosting machine model excelled in predicting Cr content after washing, determining soil suitability for washing. Furthermore, the adaptive boosting and random forest models preferably predicted Cr content after various washing agents treatments, facilitating optimal detergent identification. Based on the feature analysis, soil pH, exchangeable potassium , reactive iron oxides , and Cr sequential extraction can account for most of the differences in washing treatment. To further validate our model, we used an additional 60 experimental data points, including soil properties with pH values beyond the range of the initial 250 data points. The R 2 value of the predicted fit to the actual results was 0.801. This study provides the feasibility of improving the efficiency of technical remediation of Cr-contaminated soils.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）