Transition metal (TM)‐based bimetallic spinel oxides can efficiently activate peroxymonosulfate (PMS) presumably attributed to enhanced electron transfer between TMs, but the existing model cannot ...fully explain the efficient TM redox cycling. Here, we discover a critical role of TM−O covalency in governing the intrinsic catalytic activity of Co3−xMnxO4 spinel oxides. Experimental and theoretical analysis reveals that the Co sites significantly raises the Mn valence and enlarges Mn−O covalency in octahedral configuration, thereby lowering the charge transfer energy to favor MnOh–PMS interaction. With appropriate MnIV/MnIII ratio to balance PMS adsorption and MnIV reduction, the Co1.1Mn1.9O4 exhibits remarkable catalytic activities for PMS activation and pollutant degradation, outperforming all the reported TM spinel oxides. The improved understandings on the origins of spinel oxides activity for PMS activation may inspire the development of more active and robust metal oxide catalysts.
The Mn−O covalency was enlarged by the Co sites mainly in the octahedral configuration, which results in a decreased charge transfer energy to favor Mn–PMS interaction and enhance MnIV reduction to boost PMS activation activity of Co‐Mn spinel oxides.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Phthalates are plasticizers in various products and regarded as endocrine disruptors due to their anti-androgen effects. Environmental occurrence and toxicities of parent phthalates have been widely ...reported, while the current state of knowledge on their metabolites is rarely summarized. Based on the available literature, the present review mainly aims to 1) characterize the potential metabolites of phthalates (mPAEs) using the pharmacokinetics evidences acquired via animal or human models; 2) examine the molecular and cellular mechanism involved in toxicity for mPAEs; 3) investigate the exposure levels of mPAEs in different human specimens (e.g., urine, blood, seminal fluid, breast milk, amniotic fluid and others) across the globe; 4) discuss the models and related parameters for phthalate exposure assessment. We suggest there is subtle difference in toxic mechanisms for mPAEs compared to their parent phthalates due to their alternative chemical structures. Human monitoring studies performed in Asia, America and Europe have provided the population exposure baseline levels for typical phthalates in different regions. Urine is the preferred matrix than other specimens for phthalate exposure study. Among ten urinary mPAEs, the largest proportions of di-(2-ethylhexyl) phthalate (DEHP) metabolites (40%), monoethyl phthalate (mEP) (43%) and DEHP metabolites/mEP (both 29%) were observed in Asia, America and Europe respectively, and mono-5-carboxy-2-ethypentyl phthalate was the most abundant compounds among DEHP metabolites. Daily intakes of phthalates can be accurately calculated via urinary mPAEs if the proper exposure parameters were determined. Further work should focus on combining epidemiological and biological evidences to establish links between phthalates exposure and biological phenotypes. More accurate molar fractions (FUE) of the urinary excreted monoester related to the ingested diesters should be collected in epidemiological or pharmacokinetic studies for different population.
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•Metabolites display different toxic mechanism compared to parent phthalates.•Differences exist in distribution of phthalate metabolites in multiple human specimens.•Urinary profiles of phthalates vary markedly for people on different continents.•Reasonable FUE data are suggested for phthalate exposure assessment by human experiments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Co3O4 with a high theoretical capacitance has been widely recognized as a promising electrode material for supercapacitor, but its poor electrical conductivity and stability limit its practical ...applications. Here, we developed an effective synthetic route to synthesize one-dimensional (1D) porous ZnO/Co3O4 heterojunction composites. Benefiting from the heterostructure to promote the charge transfer and protect Co3O4 from corrosion and the 1D porous structure to improve ion diffusion and prevent structural collapse in charge and discharge process, the as-prepared ZnO/Co3O4 composites exhibited an excellent capacitive performance and good cycling stability. The specific capacitance of the ZnO/Co3O4-450 (1135 F g–1 at 1 A g–1) was 1.4 times higher than that of Co3O4 (814 F g–1), and the high-rate performance for ZnO/Co3O4-450 was 4.9 times better than that of Co3O4. Also, approximately 83% of its specific capacitance was retained after 5000 cycles at 10 A g–1. Most importantly, the as-fabricated asymmetric supercapacitor, with a ZnO/Co3O4-450 positive electrode and an activated carbon negative electrode, delivered a prominent energy density of 47.7 W h kg–1 and a high power density of 7500 W kg–1. Thus, the ZnO/Co3O4 composites could serve as a high-activity material for supercapacitor and the preparation method also offers an attractive strategy to enhance the capacitive performance of Co3O4.
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IJS, KILJ, NUK, PNG, UL, UM
The development of high‐efficiency bifunctional electrocatalyst for oxygen reduction and evolution reactions (ORR/OER) is critical for rechargeable metal–air batteries, a typical electrochemical ...energy storage and conversion technology. This work reports a general approach for the synthesis of Pd@PdO–Co3O4 nanocubes using the zeolite‐type metal–organic framework (MOF) as a template. The as‐synthesized materials exhibit a high electrocatalytic activity toward OER and ORR, which is comparable to those of commercial RuO2 and Pt/C electrocatalysts, while its cycle performance and stability are much higher than those of commercial RuO2 and Pt/C electrocatalysts. Various physicochemical characterizations and density functional theory calculations indicate that the favorable electrochemical performance of the Pd@PdO–Co3O4 nanocubes is mainly attributed to the synergistic effect between PdO and the robust hollow structure composed of interconnected crystalline Co3O4 nanocubes. This work establishes an efficient approach for the controlled design and synthesis of MOF‐templated hybrid nanomaterials, and provides a great potential for developing high‐performance electrocatalysts in energy storage and conversion.
This work reports a general approach to synthesize Pd@PdO‐Co3O4 nanocubes using the zeolite‐type metal–organic framework (MOF) as a template. The as‐synthesized material exhibits a high electrocatalytic activity toward Oxygen evolution and reduction reactions (OER and ORR). Synergistic effects between PdO and the robust hollow structure crystalline Co3O4 nanocubes are the main contributions to the catalyst's excellent performance.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Removal of organic micropollutants from water through advanced oxidation processes (AOPs) is hampered by the excessive input of energy and/or chemicals as well as the large amounts of residuals ...resulting from incomplete mineralization. Herein, we report a new water purification paradigm, the direct oxidative transfer process (DOTP), which enables complete, highly efficient decontamination at very low dosage of oxidants. DOTP differs fundamentally from AOPs and adsorption in its pollutant removal behavior and mechanisms. In DOTP, the nanocatalyst can interact with persulfate to activate the pollutants by lowering their reductive potential energy, which triggers a non-decomposing oxidative transfer of pollutants from the bulk solution to the nanocatalyst surface. By leveraging the activation, stabilization, and accumulation functions of the heterogeneous catalyst, the DOTP can occur spontaneously on the nanocatalyst surface to enable complete removal of pollutants. The process is found to occur for diverse pollutants, oxidants, and nanocatalysts, including various low-cost catalysts. Significantly, DOTP requires no external energy input, has low oxidant consumption, produces no residual byproducts, and performs robustly in real environmental matrices. These favorable features render DOTP an extremely promising nanotechnology platform for water purification.
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•Dosing reducing agents resulted in enhanced pollutant degradation and expansion of pH range.•Dosing manner of RA was a key factor governing its roles in Fenton system.•Catalytic ...mechanisms of the three reducing agents in Fenton system were proposed.•Electrical energy per order was used to estimate the costs of three reducing agents.
Fenton reaction is widely used for hazardous pollutant degradation. Reducing agents (RAs) have been proven to be efficient in promoting the generation of HO• in Fenton reaction by accelerating the redox cycle of Fe3+/Fe2+. However, the roles of different RAs in Fenton reaction remain unrevealed. In this work, the catalytic activity of three RAs, i.e., hydroxylamine (NH2OH), ascorbic acid (AA) and cysteine (Cys), on the degradation of benzoic acid (BA) and the hydroxyl radical formation in the Fenton-RAs system were investigated. Results show the catalytic performance of RAs in BA degradation by Fenton reaction followed an order of NH2OH > AA > Cys. Compared with the conventional Fenton system, the effective pH range in the Fenton-NH2OH system extended from 3.0 to 5.0, while the optimal pH in the Fenton-AA and Fenton-Cys systems ranged from 3.0 to 4.0. The Fenton-AA system exhibited a two-stage reaction toward BA degradation, which was different from the Fenton-NH2OH and Fenton-Cys systems. Furthermore, the dosing manner of AA was found to be a key factor governing its role in the Fenton-AA system. This observation suggests the different mechanisms behind the enhancement of the three RAs in Fenton system. Different from NH2OH and Cys, AA would inhibit the generation of HO•, especially at the fast stage of degradation process, where Fe3+ has not accumulated yet. In addition, the economic analysis using the electrical energy per order indicates Fenton-NH2OH system was economically feasible with the lowest energy input, compared to Fenton-AA and Fenton-Cys systems. These results are useful to better understand the roles of RAs in Fenton system, and also provide guidance about the selection and dosing manner of suitable RAs in the advanced oxidation processes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The minimal time a system needs to evolve from an initial state to its one orthogonal state is defined as the quantum speed limit time, which can be used to characterize the maximal speed of ...evolution of a quantum system. This is a fundamental question of quantum physics. We investigate the generic bound on the minimal evolution time of the open dynamical quantum system. This quantum speed limit time is applicable to both mixed and pure initial states. We then apply this result to the damped Jaynes-Cummings model and the Ohimc-like dephasing model starting from a general time-evolution state. The bound of this time-dependent state at any point in time can be found. For the damped Jaynes-Cummings model, when the system starts from the excited state, the corresponding bound first decreases and then increases in the Markovian dynamics. While in the non-Markovian regime, the speed limit time shows an interesting periodic oscillatory behavior. For the case of Ohimc-like dephasing model, this bound would be gradually trapped to a fixed value. In addition, the roles of the relativistic effects on the speed limit time for the observer in non-inertial frames are discussed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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•Air inhalation was the main pathway for indoor PAHs entering human body.•Males were more susceptible to oxidative stress when exposure to PAHs.•Oxidative potential of indoor dust was ...initially quantified with DTT assay.•PAHs with high molecular weight possibly intensified oxidative potential in dust.
A comparative study of internal and external exposure is a good method to comprehensively understand human exposure to environmental contaminants that may trigger oxidative stress in human body. Information is limited regarding the influences of reactive oxygen species (ROS) on human health from the environment. In addition, data on the contribution of polycyclic aromatic hydrocarbons (PAHs) from indoor environments, especially air, to total human exposure are still insufficient. The present study measured PAHs in paired indoor dust (n = 101), gas (polyurethane foams, n = 100), and particle samples (quartz fiber filters, n = 100) and their hydroxy metabolites (OH-PAHs) in 205 urine samples from 101 families in Guangzhou, South China. The oxidative potential (OP) in dust samples was quantified with a dithiothreitol (DTT) assay to reflect the oxidizability of ROSs, and explore the relationship between environmental ROSs and oxidative stress in humans (using urinary 8-hydroxy-2′-deoxyguanosine (8-OHdG) as a biomarker). The estimated daily intakes (EDIs) of Σ16PAH via air inhalation were much higher than those from gas dermal contact, dust dermal contact, and dust ingestion (mean: 19.5 > 4.27 > 3.75 > 1.60 ng/kg_bw/day). Generally, approximately 16% of naphthalene, 28% of fluorene, 9% of phenanthrene, and 3% of pyrene were derived from indoor environments for all residents when compared with the total PAH exposure amount from all sources. Significantly positive relationships were found between OH-PAHs and 8-OHdG (coefficients β: 0.129–0.366, p < 0.05) checked by linear mixed effect models, and males seemed to be more susceptible than females to the DNA oxidative damage related to PAH exposure. The mean OP value in dust was 7.14 ± 6.68 pmol/(min·μg). Individual PAHs in dust gradually intensified the oxidizability of dust particles as their molecular weight increased. A potential but not significant dose-relationship was found between dusty OP and urinary 8-OHdG. Further work should determine the impact of chemical profiles on OP in different environmental media and continuously explore the potential to use OP as a useful indicator to reflect the total oxidizability of several groups of environmental pollutants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We study the coherence trapping of a qubit correlated initially with a non-Markovian bath in a pure dephasing channel. By considering the initial qubit-bath correlation and the bath spectral density, ...we find that the initial qubit-bath correlation can lead to a more efficient coherence trapping than that of the initially separable qubit-bath state. The stationary coherence in the long time limit can be maximized by optimizing the parameters of the initially correlated qubit-bath state and the bath spectral density. In addition, the effects of this initial correlation on the maximal evolution speed for the qubit trapped to its stationary coherence state are also explored.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The tectonic deformation reaction to multi‐plate convergence in the northern Guizhong Depression, as well as its geodynamic process, remain poorly understood. Two phases of intracontinental ...deformation are identified using field geological investigations, paleo‐stress inversion and seismic reflection sections: (1) early NE–SW‐directed compression during the Middle Triassic to Early Jurassic; (2) later NW–SE‐directed compression during the Middle Jurassic to Early Cretaceous. The reconstruction of paleo‐stress provides robust constraints on the spatiotemporal evolution of stress within the Guizhong Depression. The regional SW–NE‐directed compression during the Middle Triassic to Early Jurassic was driven by the collision and convergence between the Indochina and South China blocks, resulting in the formation of NW–SE‐directed compressional structures during the Indosinian Period. The later SE–NW‐directed paleo‐stress field was probably driven by the NW‐directed subduction of the Paleo–Pacific Plate during the Middle Jurassic to Early Cretaceous.
The Guizhong Depression suffered two periods of compression during the Mesozoic. The early NE–SW‐directed compression was caused by the collision of the Indochina and South China blocks during the Middle Triassic to Early Jurassic, but the later NW–SE‐directed compression was caused by north‐westward flat‐slab subduction of the Paleo–Pacific Plate during the Middle Jurassic to Early Cretaceous.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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