CHEMOSPHERE
·
2022
·
IF 8.943
Jinghao Wang,Huimin Liu,Song Song,Yuancai Chen,Yongyou Hu
Microbial electron output capacity is critical for organic contaminants biodegradation. Herein, original C. freundii JH could oxidate formate in anaerobic respiration, but lack the ability to degrade sulfamethoxazole (SMX). While the incorporation of Pd(0) could effectively improve the electron output via improving the combination between flavins and c-type cytochromes (c-Cyts), increasing the activities of key enzymes (formate dehydrogenase , hydrogenase, F 0 F 1 -ATPases), etc. More importantly, the presence of Pd(0) caused the NADH dehydrogenase (complex I) nearly in idle, and triggered the decrease of NADH/NAD + ratio and increase of H + -efflux transmembrane gradient, eventually resulting in the electrons diverting from CoQ-involved long respiratory chain (decreasing from 91.67% to 36.25%) to FDH/Hases-based hydrogen-producing short chain (increasing from 22.44% to 84.88%), which further intensified the electron output. Above changes effectively launched and guaranteed the high-level SMX degradation by palladized C. freundii JH, alleviating the ecotoxicity of SMX in aquatic and terrestrial environments. These conclusions provided the new view to regulate the microbial electron output behaviors.
研究领域:
环境微生物学
·
生物修复
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电子传递
·
环境毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ENVIRONMENTAL MANAGEMENT
·
2020
·
IF 5.647
Lu Zhou,Jixian Yang,Fang Ma,Shanshan Pi,Aiqi Tang,Ang Li
Palladium (Pd) is extremely expensive due to its scarcity and excellent catalytic performance. Thus, the recovery of Pd has become increasingly important. Herein, microbial extracellular polymeric substances (EPS) and magnetic nanocomposite EPS@Fe 3 O 4 were applied to recover Pd catalysts from Pd(II) wastewater. Results indicated that Pd(II) was reduced to Pd (0), which was then adsorbed by EPS (101.21 mg/g) and EPS@Fe 3 O 4 (126.30 mg/(g EPS)). After adsorbing Pd, EPS@Fe 3 O 4 could be collected by magnetic separation. The recovered Pd showed excellent catalytic activity in the reduction of methylene blue (MB). The pseudo-second-order kinetic model and Redlich-Peterson model best fit the adsorption results. According to spectral analysis, Pd(II) was reduced to Pd (0) by chemical groups in EPS and EPS@Fe 3 O 4 , and the hydroxyl had a chelating effect on adsorbed Pd. Therefore, EPS@Fe 3 O 4 is an efficient adsorbent for recovering Pd from Pd(II) wastewater.
研究领域:
环境科学
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材料科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Jinghao Wang,Sijing Bi,Yuancai Chen,Yongyou Hu
Gram-negative Citrobacter freundii with high Pd (II) reduction capacity was isolated from electroplating wastewater, and the electron transfer involved in Pd (II) bio-reduction by C. freundii JH was investigated in phosphate buffer saline solution with sodium formate as sole electron donor under anaerobic condition . FTIR spectra indicated that hydroxyl and amine groups on cell wall participated Pd (II) bio-sorption. TEM , XRD, XPS results confirmed that Pd (0) nanoparticles (NPs) could be bio-synthesized intra/extracellularly. Meanwhile, pH turn-over were observed owing to the reduction of cytochrome c (c-Cyt) in bio-reduction process. EPR spectra indicated that free radicals ( OH) was generated from high concentration Pd (II), which would cause seriously damage to cell. Despite of the lower tolerance to Pd (II), the cells at logarithmic phase exhibited higher Pd (II) reduction capacity (72.21%) than that at stationary phase (56.21%), which might be related to the relatively stronger proton motive force (PMF) created by the substrate oxidation and the electron transfer, as evidenced by electrochemical experiments (CV, DPV, amperometric I-t curves) and protein denaturalization experiments. Additionally, c-Cyt and riboflavin were confirmed to be important participants in electron transfer. Finally, a putative synthesis mechanism of Pd (0)-NPs was deduced. This study contributed to further understanding the electron transfer in Pd (II) reduction, and provided more information for the bio-synthetic of metal nanoparticles.
研究领域:
环境微生物学
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生物技术
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纳米技术
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微生物生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Jinghao Wang,Wenmin Lin,Yuancai Chen,Yongyou Hu,Qijin Luo
Due to the excellent hydrogen affinity and high conductivity, palladium nanoparticles (Pd NPs) were considered as a potential strategy to regulate bacterial electron transfer and energy metabolism. Herein, Citrobacter freundii JH, capable of in-situ biosynthesizing Pd(0) NPs, was employed to promote Pt(IV) reduction. The results showed that the Pt(IV) reduction to Pt(II) was accomplished mainly via the flavins-mediated extracellular electron transfer (EET) process, while Pt(II) reduction to Pt(0) was limit step, and proceeded via two intracellular respiratory chains, including FDH/Hases-based short chain (S-chain) and typical CoQ-involved long respiratory chain ( L -chain). Noteworthily, the incorporation of Pd(0) NPs mainly diverted the electrons to S-chain (as high as 71.7%−73.4%) by improving the hydrogenases (Hases) activity. Furthermore, Pd(0) NPs could stimulate the secreting of flavins and the combination between flavins and cytochrome c (c-Cyt), which converted electron transfer manner of L -chain. Additionally, Pd(0) NPs might also act as alternative proton channels to improve the energy metabolism. These findings provided significant insights into the promotion by Pd(0) NPs in terms of electron generation, electron consumption and proton translocation.
研究领域:
纳米技术
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微生物学
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生物化学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Wenhui Zou,Yingcen Liu,Caicheng Song,Hua Lin,He Huang,Wanyue Ye,Rongwen Lu,Shufen Zhang
A series of PdO@MCM-41-x was in situ synthesized by a facile one-pot method, and their catalytic performance for dehydrogenation of formic acid was investigated. The PdO nanoparticles were immobilized in MCM-41 channel with small size of 2.2–2.5 nm due to the confinement of mesoporous silica . The initial turnover frequency (TOF) of as-prepared catalyst can reach 1096 h −1 at 323 K with 100% hydrogen selectivity. The hydrogen production activity was better than that of catalyst priorly reduced by hydrogen because of the gradual reduction of PdO nanoparticles and generation of fresh Pd(0) during the formic acid dehydrogenation process, which was confirmed by XPS characterization and catalytic system monitoring. It provides a new way for the preparation of simple and efficient catalysts for hydrogen production , which has great application potential.
研究领域:
化学
·
催化材料科学
✓ 已验证
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2018
·
IF 3.974
Zhuyu Niu,Yating Jia,Yuancai Chen,Yongyou Hu,Junfeng Chen,Yuancai Lv
This study constructed a biological-inorganic hybrid system including Pseudomonas putida ( P. putida ) and bioreduced Pd (0) nanoparticles (NPs), and inspected the influence of bio-nano Pd (0) on the direct electron transfer and phenol biodegradation. Scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX) showed that bio-nano Pd (0) (~10 nm) were evenly dispersed on the surface and in the periplasm of P. putida . With the incorporation of bio-nano Pd (0), the redox currents of bacteria in the cyclic voltammetry (CV) became higher and the oxidation current increased as the addition of lactate, while the highest increase rates of two electron transfer system (ETS) rates were 63.97% and 33.79%, respectively. These results indicated that bio-nano Pd (0) could directly promote the electron transfer of P. putida . In phenol biodegradation process, P. putida -Pd (0)− 2 showed the highest k (0.2992 h −1 ), μ m (0.035 h −1 ) and K i (714.29 mg/L) and the lowest apparent K s (76.39 mg/L). The results of kinetic analysis indicated that bio-nano Pd (0) markedly enhanced the biocatalytic efficiency, substrate affinity and the growth of cells compared to native P. putida . The positive effects of bio-nano Pd (0) to the electron transfer of P. putida would promote the biodegradation of phenol.
研究领域:
环境科学
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微生物学
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纳米技术
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生物催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2016
·Vol. 146
·期 9
·1792-1799
·
IF 2.294
Wang Peng,Wang Guang-Yu,Qiao Wen-Long,Feng Yi-Si
Abstract In this study, palladium (0) nanoparticle supported on mesoporous carbon (Pd/MPC) is prepared by impregnation and H 2 reduction. Characterization by XRD, XPS and TEM reveals the mesoporous structure and a high dispersion of palladium nanoparticles (about 4.8 nm) in the mesopores. The catalyst has excellent catalytic activity and stability for Sonogashira reactions of aryl halide (–I, –Br) in aqueous solution. It is noteworthy that Sonogashira reactions of aryl halide (–Cl) can occur by using the novel Pd/MPC catalyst. Meanwhile, the catalyst can be recovered and reused without loss of efficiency until the fifth cycle in water. The fresh catalyst would be of major significance for industrial applications. Graphical Abstract
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2019
·
IF 0
Jinglu Chen,Mingtao Qiao,Wenyan Wang,Qiuyu Zhang
It is well known that palladium-catalyzed cross-coupling Suzuki reaction is very important way to build organic compound carbon skeleton. However, when some reactants such as chlorobenzene are used as substrates which has low reactivity, only moderately low yields were obtained using such kind of mobilized catalyst, Insufficient loading on the normal carrier, the problem of easy aggregation of palladium and large particle size of Pd were considered as reasons of it. A novel magnetic mesoporous Fe 3 O 4 @Void@mSiO 2 nanochains with yolk-shell structure have been first developed to solve the problems via magnetic-field induced distillation-precipitation polymerization together with a facile sol-gel method and the final calcination . Interestingly, we found that some pleated layers grown on the surface of Fe 3 O 4 @void@mSiO 2 nanochains during the hydrolysis of 3-aminopropyltriethoxysilane (KH-550) and special microstructures endow them with excellent porosity which are helpful for increasing the loading capacity of Pd nanoparticles . Owing to high aspect ratio and superparamagnetism , the magnetic nanochains can rotate in the water or organic solution and be separated and recycled easily with the drive of alternating magnetic field. In this catalysis system, the orderly mesoporous opening structure of the hollow mesoporous nanochains could effectively facilitate the transfer of reactant molecules, and the existence of the internal cavities would effectively prolong the action time of the Pd nanoparticles for the Suzuki reaction. The reaction yields of coupling reaction between bromobenzene/chlorobenzene and phenylboronic acid catalyzed by the nanochains can reach nearly 100% respectively. and the reaction yields can still maintain 92.93% and 60.86% after 7 cycles, respectively.
研究领域:
材料科学
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化学工程
·
纳米技术
✓ 已验证
DOI
NEW JOURNAL OF CHEMISTRY
·
2015
·Vol. 39
·期 6
·4519-4525
·
IF 3.086
Yansheng Liu,Xinlin Li,Xuanduong Le,Wei Zhang,Hao Gu,Ruiwen Xue,Jiantai Ma
MCM-48 mesoporous microspheres (M48N) with a pore size of 3.77 nm, an ultra-high surface area of 1250.77 m2 g−1 and a super-large pore volume of 1.52 cm3 g−1 were synthesized. The M48N microspheres were then modified with Pd, Pt and Ru nanoparticles using an incipient wetness impregnation technique. The modified M48N microspheres were investigated to determine their catalytic effect in the aqueous phase hydro-dechlorination (HDC) of 4-chlorophenol. The Pd–M48N, Pt–M48N and Ru–M48N catalysts were characterized by transmission electron microscopy, X-ray diffraction, nitrogen adsorption–desorption and X-ray photoelectron spectroscopy. The HDC experiments were performed using the fairly mild conditions of room temperature and an atmospheric pressure of H2. Pd–M48N showed a higher catalytic performance than Pt–M48N and Ru–M48N and various other Pd-based catalysts. The high catalytic performance of Pd–M48N resulted from the ultra-high surface area, super-large pore volume and unique pore structure of the M48N, which improved the mass transfer and increased the rate of adsorption–desorption of the compounds. This method has potential applications in the treatment of industrial wastewaters contaminated with chlorinated organic compounds.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
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