ACS Catalysis
·
2023
·
IF 12.9
Zhao Sun,Shufan Yu,Sam Toan,Rufat Abiev,Maohong Fan,Zhiqiang Sun
Steam reforming of methanol is a promising approach to achieving hydrogen storage, transportation, and in situ supply. However, this technology is restricted by its high CO selectivity and catalyst deactivation. In this study, CuCr2O4-based catalytic oxygen carriers are tailored for lattice oxygen participating in low-temperature methanol reforming. We found that the low-temperature activation of methanol originated from Cu–O–Cr structure intensification and highly activated lattice oxygen induction. Specifically, methanol can be activated at temperatures as low as 160 °C, on the one hand, attributed to the reinforcement of the Cu–O–Cr structure and, on the other hand, owing to the highly reactive lattice oxygen from the CuO4 tetrahedron in the CuCr2O4 spinel. Combined with XAS and Raman results, the formation of the Cu–O–Cr structure is demonstrated. The hydrogen production rate with an applied CuCr2O4-based catalytic oxygen carrier is 53.2% higher than the control group without Cu–O–Cr formulation. Satisfactory cyclic stability is retained after the 50th lattice oxygen induction and supplement cycle, ascribing to the Cu–O–Cr structure that strongly intensifies Cu–Cr2O3 interactions. DFT results reveal that the process of CH3OH → CH3O* is the rate-determining step. Compared to Cu(111) and Cr2O3(110), the tailored Cu(111)/Cr2O3(110) surface with a Cu–O–Cr structure exhibits the lowest potential barrier during this process, promoting low-temperature methanol reforming.
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2023
·
IF 12.8
Tao Yang,Cui Huang,Linqian An,Ge Zeng,Juan Li,Changyu Liu,Xiaolong Xu,Jianbo Jia,Jun Ma
Hexavalent chromium (Cr(VI)) is ubiquitous in natural environments, whereas its role in the transformation of coexisting contaminants may have been overlooked. In this work, it was reported for the first time that the irradiation of Cr(VI) by solar light (solar light/Cr(VI) system) could effectively degrade various micropollutants with different structures. The removal efficiency of selected micropollutants was increased by 13.3–64.8% by the solar light/Cr(VI) system compared to that by direct solar photolysis. Meanwhile, the oxidation rates were enhanced by 2.2–21.5 folds, while they were negligible by Cr(VI) oxidation alone. Experiments by specific scavengers, probe compounds, fluorescence absorbance, and electron spin resonance analysis demonstrated that hydroxyl radical (•OH) was the major reactive species in the solar light/Cr(VI) system. Further experiments showed that the generation of •OH was closely related to the intermediate Cr(V) generated from Cr(VI) reduction, and Cr(V) could be re-oxidized back to Cr(VI). Increasing solution pH negatively affected model micropollutant (carbamazepine (CBZ)) degradation by the solar light/Cr(VI) system, mainly due to the decreased quantum yield of •OH at higher pH. Coexisting sulfate ions showed negligible effect on CBZ degradation in the solar light/Cr(VI) system, while the presence of bicarbonate , chloride, and humic acid inhibited CBZ degradation to varying degrees, owing to their diverse scavenging effects on •OH. Furthermore, moderate CBZ degradation was also achieved by natural solar light photolysis of Cr(VI). This study demonstrated the pivotal role of Cr(VI) in the transformation of micropollutants under solar irradiation, which advances the understanding of the fate of micropollutants in natural environments.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2023
·Vol. 31
·期 7
·2999-3014
·
IF 5.3
Song Jie,Chen Lijun,Niu Yuhua,Wei Zhiqiang,Sun Yonghui
From the perspective of environmental protection, high removal rate, reusable and degradable, amino-functionalized porous hydrogel material P-(EA-β-CD/KHA/AC) was synthesized by introducing ethylamino cyclodextrin, humic acid, and activated carbon, using polyacrylic acid as the carrier. MB and Cr (VI) are common wastewater pollutants, thus, Such contaminants must be removed from the water. The gel materials before and after adsorption were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The removal of MB and Cr(VI) showed high adsorption capacity. At 298 K and pH 8, the adsorption capacities of P-(EA-β-CD/KHA/AC) hydrogel for MB and Cr(VI) were as high as 262.31 and 170.12 mg/g, respectively, and the removal rates were 98.96% and 70.27%, respectively. The adsorption behavior follows the pseudo-second-order kinetic equation, conforming to the Langmuir model; and through intermolecular forces, π–π conjugation, chelation, and other interactions, entropy-increasing, endothermic, and spontaneous process is formed. The regeneration and degradability experiments of P-(EA-β-CD/KHA/AC) hydrogel were conducted and its recycling performance was verified.
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Xu Yan,Mengmeng Song,Mo Zhou,Chunlian Ding,Zhongren Wang,Yunyan Wang,Weichun Yang,Zhihui Yang,Qi Liao,Yan Shi
CuO nanoparticles (NPs) released into aqueous environments induce metal toxicity, which generally exerts negative effects on various organisms and leads to great challenge for wastewater biotreatment. In this study, a promotion effect of CuO NPs on biological process was first found. Cr(VI) reduction by Cupriavidus basilensis B-8 (hereafter B-8) was enhanced in the presence of CuO NPs. The efficiency of Cr(VI) bioreduction was much higher with B-8 and CuO NPs (approximately 100%) than with B-8 (approximately 37.6%) and CuO NPs (39.9–44.7%) alone, indicating a stimulatory effect of CuO NPs on Cr(VI) reduction by B-8. Our material analyses revealed different response mechanisms of B-8 to Cr(VI), with and without CuO NPs. The addition of CuO NPs influenced the interaction of Cr(VI) with the N-, P-, S-, and C-related functional groups of B-8. Transcriptomic analysis indicated that multiple mechanisms, including Cr(VI) uptake and reactive oxygen species detoxification, were induced by Cr(VI). Many genes involved in various metabolic processes were significantly upregulated by the addition of CuO NPs. To a certain extent, the pressure of DNA repairment by B-8 induced by Cr(VI) was also alleviated by the presence of CuO NPs. They contributed to facilitate B-8 growth and enhance Cr(VI) reduction, even with 50 mg/L Cr(VI). This study not only elaborated the mechanisms of bacterial Cr(VI) reduction when enhanced by CuO NPs, but also provided a novel perspective for wastewater biotreatment.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Earth and Space Chemistry
·
2019
·
IF 2.243
Zhipeng Shu,Lihu Liu,Guohong Qiu,Xiong Yang,Mingzhe Zhang,Wenfeng Tan,Chengshuai Liu,Fei Wu
The formation and transformation of schwertmannite affect the migration, conversion, and toxicity of chromium (Cr) in soils and sediments. Schwertmannite could be obtained from the oxidation of Fe(II) by hydroxyl radicals (OH•) and superoxide radicals (O2•–) generated from the photolysis of NO3– under acidic and sulfate-rich conditions. As one of the most abundant components, montmorillonite is widely distributed in soils and sediments. However, the effect of montmorillonite on the photochemical formation process and corresponding Cr adsorption behaviors of schwertmannite remains elusive. This study indicates that schwertmannite could be formed on the montmorillonite surface during the photocatalytic oxidation of dissolved Fe(II). The formation rate, particle size, and crystallinity degree of schwertmannite formed on montmorillonite surface increased with increasing FeSO4 concentration (1.0–5.0 mmol L–1). The presence of montmorillonite led to a decrease in the particle size of schwertmannite. When the initial concentration of Fe(II) was 5.0 mmol L–1, the specific surface area of schwertmannite–montmorillonite aggregates reached 243.3 m2 g–1, which was remarkably larger than that of single-phase schwertmannite (24.6 m2 g–1) and montmorillonite (138.1 m2 g–1). The schwertmannite–montmorillonite aggregates showed a higher adsorption capacity for Cr(VI) (97.4 mg Cr g–1 Fe) than single-phase schwertmannite (72.9 mg Cr g–1 Fe). This work reveals the possible formation pathway and Cr adsorption behavior of schwertmannite on the surface of montmorillonite in waters and soils.
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Jinfeng Mei,Hui Zhang,Zhongyu Li,Hongxiang Ou
A kind of water-soluble chitosan, chitosan oligosaccharide, was used to synthesize a crosslinking hydrogel using a simple method, and the outstanding adsorption property of the hydrogel for Cr(VI) was investigated. The three-dimensional structure of the synthetic material was analyzed by means of 13 C solid state nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) measurements. The hydrogel also exhibited high thermal stability and mechanical strength. Its adsorption capacity for Cr(VI) reached 148.1 ± 2.4 mg/g with a fast adsorption rate. Pseudo-second-order kinetic model and Langmuir isotherm well described the adsorption process. Notably, the hydrogel still showed 100% removal efficiency for Cr(VI) at low concentration (0.02–1 mg/L) in the detectable range. The simple preparation process, high mechanical strength and excellent adsorption property indicate that the hydrogel has great potential for the removal of Cr(VI) ions from water and wastewater.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 13
·5039-5046
·
IF 3.069
Yao Chen,Shihao Xu,Shuai Han,Suyun Chu,Liang Yang,Changlong Jiang
Poly(m-phenylenediamine) (PmPD) is an efficient material for the adsorption of Cr(VI). However, it is facile to aggregate in water, which reduces its adsorption capacity, and it is not facile to be separated from water. Hence, magnetic or membrane structures by compositing PmPD with other functional materials are usually synthesized to solve the above problems. Here, we utilized polyvinyl alcohol (PVA) chains to obtain a dense network structure, which embedded and constrained PmPD into the network to form a membrane. PmPD constrained in the membrane existed stably and was facilely separated from water due to the large size of the membrane. Meanwhile, the PmPD/PVA membranes showed good mechanical properties and combined both the extraordinary adsorption capacity and reusability. In this study, the maximum Cr(VI) adsorption capacity of the composite membrane structures was 498.87 mg g−1 at room temperature. The adsorption and removal mechanism can be explained by the fact that the protonated imine units adsorb Cr(VI) via electrostatic attraction; following this, Cr(VI) changed to Cr(III) by reduction and chelated on the imine units. This study demonstrated that the PmPD/PVA membrane has a great potential for the separation of Cr(VI) from wastewater due to its low-cost and high adsorption capacity.
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2018
·Vol. 25
·期 23
·22455-22463
·
IF 2.8
Wang Pingping,Dong Faqin,Liu Mingxue,He Huichao,Huo Tingting,Zhou Lei,Zhang Wei
Photoelectrochemical process is an environmentally friendly technology and has a wide application in the control of environmental pollutants. Efficient nanophotocatalysts responsive to visible light are still highly attractive. In this work, α-Fe 2 O 3 /TiO 2 were grown on fluorine doped tin oxide (FTO) substrates by hydrothermal method for photoelectrochemical reduction of Cr(VI). Compared with the separate α-Fe 2 O 3 and TiO 2 electrodes, the composite α-Fe 2 O 3 /TiO 2 electrodes show higher photocurrent density. Under visible light irradiation, 100% removal efficiency of Cr(VI) was obtained after 40 min treatment. The composite α-Fe 2 O 3 /TiO 2 electrodes showed an enhanced absorbance in visible light region and had good stability to photoelectrochemical reduction of Cr(VI). The role of hole scavengers (citric acid and oxalic acid) and pH values was systematically investigated. This novel intensification approach provides new insight on the application of photoelectrochemical reduction in environmental remediation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 11
·9006-9015
·
IF 3.201
Huating Sun,Tianxing Wu,Yunxia Zhang,Dickon H. L. Ng,Guozhong Wang
Molybdenum disulfide (MoS2) was successfully synthesized via a facile one-step hydrothermal method without addition of templates or surfactants. The obtained MoS2 product was characterized via various techniques including FESEM, HRTEM, XRD, BET and XPS analyses. Their application in capturing Cr(VI) ions in water was investigated. The results showed that the MoS2 nanosheets were ultrathin with a thickness of 5–10 nm and had a uniform lateral size of 100–200 nm. Impressively, these MoS2 nanosheets not only possessed enlarged interlayer spacing, but also had multiple defects on the basal planes, which were proved to be crucial in the removal of Cr(VI). The kinetics of chromium adsorption was found to follow the pseudo-second-order rate equation and the adsorption isotherm data were well fitted to the Langmuir model with a chromium in-take capacity of about 84.03 mg g−1. This structure-enhanced removal was likely related to the synergism of adsorption and reduction, in which the anionic Cr(VI) was adsorbed on the surface of D-MoS2via electrostatic interaction. At the same time, some fraction of the adsorbed Cr(VI) was reduced to low toxic Cr(III) and the generated Cr(III) species were adsorbed by the adsorbent. More significantly, the adsorption and reduction processes not only transferred the Cr(VI) from the aqueous environment to the surface of solid adsorbents but also alleviated the toxicity of Cr(VI). It was evident that this study may promote the application of other transition metal dichalcogenides in environmental remediation.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
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.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 18
·
IF 1.86
Shizhen Zhao,Xun Song,Xiuming Bu,Chong Zhu,Gang Wang,Fang Liao,Siwei Yang,Miao Wang
Because of the great demand for fluorescent materials, fluorescent dyes, semiconductor quantum dots, and carbon-based quantum dots have been studied extensively. However, the poor photostability and potential biological toxicity need to be resolved. In this study, we demonstrated the synthesis of a new biomass quantum dot, the polydopamine dot (PDADs), via a simple hydrothermal method under an acidic environment. This new biomass quantum dot showed not only remarkable photoluminescence properties (quantum yield = 0.93) but also a high stability and low toxicity. Moreover, these PDADs could be used as a fluorescent probe for the rapid detection of Cr(VI) (response time = 0.01 s). The detection limit (1 × 10 −11 M ) is the lowest detection limit reported for Cr(VI) fluorescent probes. The mechanism efficient quenching progress could have been due to the fast redox progress between the PDADs and Cr(VI). Moreover, we also showed a practical application of PDADs for Cr(VI) detection in vitro . © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44784.
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2017
·Vol. 9
·期 17
·3364-3373
·
IF 4.803
Qiaoqiao Sun,Ruihua Cheng,Zhen Liu,Xuelian He,Ning Zhao,Boping Liu
Graphical The fluorine effect : Fluorinated Phillips catalysts (Cr/F-SiO 2 ) exhibit an enhanced reactivity towards ethylene polymerization and copolymerization. DFT calculations show that the difference of the Gibbs free energy barriers between chain transfer and chain propagation increased after the introduction of the fluoride onto the silica surface, which is in accordance with the increased molecular weight of the polyethylene formed using the Cr/F-SiO 2 catalyst. In this work, a fluoride-modified Phillips catalyst was investigated by using combined experimental and computational methods. The addition of fluoride to the Phillips Cr/SiO 2 catalyst can increase the activity of the catalyst calcined at a low temperature and the molecular weight of the polyethylene product. DFT calculations were performed to show that the difference of the Gibbs free energy barriers between chain transfer and chain propagation increased after the introduction of the fluoride onto the silica surface, which is in accordance with the increased molecular weight of the polyethylene produced by the fluoride-modified Phillips Cr/F-SiO 2 catalyst. The computational results also reflect the increase of the activity of the ethylene/1-hexene copolymerization after the introduction of fluoride, although the modification has little effect on the regioselectivity of the produced ethylene/1-hexene copolymer. Moreover, copolymers produced by the fluoride-modified Phillips catalyst with more short-chain branches (SCBs) in the high-molecular-weight fraction and a significant enhancement of the environmental stress crack resistance can be explained from the results of the DFT calculations.
✓ 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）