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1.
Langmuir ; 40(24): 12443-12453, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38833582

RESUMO

The nature always offers amazing inspiration, where it is highly desirable to endow coatings on marine equipment with powerful functions. An excellent example is slippery zone of Nepenthes pitcher, which possesses novel liquid-repellent and self-cleaning performance. Therefore, this study presents an efficient fabrication method to prepare a novel coating. The coatings were fabricated by designing biomimetic textures extracted from the lunate bodies of slippery zone on polydimethylsiloxane (PDMS) and then grafting Dictyophora indusiata polysaccharide (DIP) modifier. The as-prepared slippery coatings exhibited outstanding antifouling properties against kinds of daily life pollutants such as Chlorella and coffee. This synergistic strategy was proposed combined with environmentally friendly modifier grafting and heterogeneous microstructure on the surface to broaden new probabilities for manufacturing slippery coatings with incredible protective functionality.

2.
Environ Sci Pollut Res Int ; 31(5): 7380-7395, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38159186

RESUMO

In recent years, the construction of smart cities has gradually become an effective means of addressing urban economic and environmental challenges. Based on panel data of 249 Chinese cities from 2005 to 2020, this study uses a super-efficiency epsilon-based measure model and a Malmquist-Luenberger index to calculate the urban green total factor productivity (GTFP). Using the smart city pilot as a quasi-natural experiment, the time-varying difference-in-difference (DID) method is applied to determine the causal effect of smart city pilot on GTFP. Results show that smart city pilot increases urban GTFP in China, and a series of robust analyses have verified the reliability of the results. The heterogeneity analysis results show that the smart city pilot policy has a more significant positive effect on urban GTFP in the eastern and central regions, the high population group, and the high per capita GDP group. The mediating analysis further suggests that smart city pilot positively affects technological innovations and human capital which promotes urban GTFP. These findings are of great significance for smart city construction and coordinating the relationship between urban economic development and environmental protection.


Assuntos
Desenvolvimento Econômico , Desenvolvimento Sustentável , China , Cidades , Reprodutibilidade dos Testes
3.
Ecotoxicol Environ Saf ; 267: 115669, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37944464

RESUMO

Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is one of the most destructive insect pests owned strong resistance to different insecticides. Indoxacarb as a novel oxadiazine insecticide becomes the main pesticide against S. litura. DIMBOA [2,4-dihydroxy-7-methoxy-2 H-1,4-benz-oxazin-3(4 H)-one] is involved in important chemical defense processes in corn plants. However, the insects' adaptation mechanism to insecticides when exposed to defensive allelochemicals in their host plants remains unclear. Here, we assessed multi-resistance, and resistance mechanisms based on S. litura life history traits. After 18 generations of selection, indoxacarb resistance was increased by 61.95-fold (Ind-Sel) and 86.06-fold (Dim-Sel) as compared to the Lab-Sus. Also, DIMBOA-pretreated larvae developed high resistance to beta-cypermethrin, chlorpyrifos, phoxim, chlorantraniliprole, and emamectin benzoate. Meanwhile, indoxacarb (LC50) was applied to detect its impact on thirty-eight detoxification-related genes expression. The transcripts of SlituCOE073, SlituCOE009, SlituCOE074, and SlituCOE111 as well as SlGSTs5, SlGSTu1, and SlGSTe13 were considerably raised in the Ind-Sel strain. Among the twenty-three P450s, CYP6AE68, CYP321B1, CYP6B50, CYP9A39, CYP4L10, and CYP4S9v1 transcripts denoted significantly higher levels in the Ind-Sel strain, suggesting that CarEs, GSTs and P450s genes may be engaged in indoxacarb resistance. These outcomes further highlighted the importance of detoxification enzymes for S. litura gene expression and their role in responses to insecticides and pest management approaches.


Assuntos
Inseticidas , Animais , Spodoptera/fisiologia , Inseticidas/farmacologia , Nicotiana/metabolismo , Benzoxazinas , Larva/metabolismo , Expressão Gênica , Resistência a Inseticidas/genética
4.
Water Res ; 240: 120081, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37224667

RESUMO

Pore wetting induced by surfactants and salt scaling is a major obstacle to the industrial application of membrane distillation (MD). Identifying the transition of wetting stages and achieving early monitoring of pore wetting are crucial for wetting control. Herein, we made a pioneering attempt to use ultrasonic time-domain reflectometry (UTDR) technique to non-invasively detect the pore wetting in a direct contact MD, and explain the UTDR waveform with the help of optical coherence tomography (OCT) imaging. The results showed that the water-vapor interface had a strong reflection to ultrasound (reflection coefficient = 0.9995), while the water-membrane and water-scaling layer interfaces showed relatively weak reflection. Therefore, UTDR could effectively detect the movement of water-vapor interface with the low interference from the signals generated by the membrane and scaling layer. For the surfactant-induced wetting, the occurrence of wetting could be successfully detected by the right-shift in phase and the reduction in amplitude of the UTDR waveform. Moreover, the wetting depth could be accurately calculated by the time of flight (ToF) and ultrasonic velocity. For scaling-induced wetting, the waveform slightly shifted to the left at the beginning due to the growth of scaling layer, then to the right because the left-shift was surpassed by the right-shift of the waveform caused by pore wetting. Both for the surfactant- and scaling-induced wetting, the variation of the UTDR waveform was sensitive to wetting dynamics, and the right-shift of phase and the reduction in amplitude of the waveform could act as early monitoring signals to the occurrence of wetting.


Assuntos
Ultrassom , Purificação da Água , Purificação da Água/métodos , Membranas Artificiais , Água , Vapor
5.
Artigo em Inglês | MEDLINE | ID: mdl-36833842

RESUMO

Green total factor productivity (GTFP) is an excellent index for green development. The objective of this study was to check whether environmental regulation (ER) can affect GTFP through the mediating role of foreign direct investment (FDI) quantity and quality. Using the super-efficiency Epsilon-based measure (EBM) model and a Malmquist-Luenberger (ML) index, China's GTFP growth was measured during 1998-2018. On this basis, we adopted a Systematic Generalized Method of Moments (SYS-GMM) to analyze the effect of ER on GTFP. The findings show that China's GTFP declined first and rose again during the sample period. GTFP in the coastland was greater than that in the inland region. ER positively affected China's GTFP growth. FDI quantity and quality mediated the nexus between ER and GTFP growth in the whole nation. Specifically, this mediation role of FDI quantity and quality was only significant in coastal China. Additionally, financial development can also boost GTFP growth in China. Given the importance of developing a green economy, the government should improve the FDI quality and attract green FDI.


Assuntos
Desenvolvimento Econômico , Eficiência , Investimentos em Saúde , China , Internacionalidade
6.
Bioresour Technol ; 367: 128241, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36332871

RESUMO

Chicken manure is a source of antibiotic resistance genes (ARGs) and pathogenic microbes. Mikania micrantha Kunth (MM) is an invasive plant containing phytochemicals as antimicrobial agents. To explore its impacts on ARGs and pathogen-host interactions (PHIs), MM was added to composting mixtures. The findings indicated that compared with control (CK), MM significantly improved the phytochemical abundances, particularly stilbenoids and diarylheptanoids (4.87%), and ubiquinones (2.66%) in the treatment (T) compost. Besides, significant ARGs reduction was noted, where rpoB2, RbpA, FosB1, vatC, and vatB were removed from T compost. PHIs significantly declined in T compost, where the growth of Xanthomonas citri, Streptococcus pneumoniae, Fusarium graminearum, Vibrio cholerae, and Xanthomonas campestris were inhibited. Multiple variable analyses demonstrated that temperature and pH revealed a significant role in ARGs and PHIs decline. Accordingly, this study considerably recommends MM as a promising compost additive in terms of its antimicrobial potential toward pathogenic microbes and ARGs.


Assuntos
Compostagem , Mikania , Animais , Esterco/análise , Galinhas/genética , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/genética , Compostos Fitoquímicos
7.
Int J Public Health ; 68: 1606602, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38179320

RESUMO

Objectives: To evaluate the impact of comprehensive medical reform on the efficiency of medical resource allocation in China. Methods: This study employs the Slacks-Based Measure- Directional Distance Function (SBM-DDF) to estimate the efficiency of medical resource allocation (MRAE) in China, using panel data from 30 provinces during 2009-2021. Moreover, a multi-period Difference in differences (DID) model is developed to explore the effect of the comprehensive medical reform pilot (CMRP) strategy on efficiency of medical resource allocation in China. Results: The results show that the average value of China's medical resources allocation efficiency is 0.861 during the sample period. Coastal area has a higher MRAE than that in the inland area. The DID results show that the comprehensive medical reform pilot strategy has a good, long-lasting impact on the efficiency of medical resource allocation. And the results remain valid after a series of robustness analysis. Additionally, the comprehensive medical reform policy has heterogeneous impact on efficiency of medical resource allocation. The promotion effect is only statistically significant in the eastern and central regions, the groups of higher MRAE and larger population size. Conclusion: China's comprehensive medical reform policy can effectively promote the improvement of regional efficiency of medical resource allocation.


Assuntos
Reforma dos Serviços de Saúde , Alocação de Recursos , Humanos , China
8.
Pestic Biochem Physiol ; 187: 105215, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36127062

RESUMO

Herbivore-induced plant volatiles (HIPVs) have been associated with plant-plant-herbivorous-natural enemies communication and an enhanced response to the subsequent attack. Spodoptera litura is a serious cosmopolitan pest that has developed a high level of resistance to many insecticides. However, the underlying molecular and biochemical mechanism by which HIPV priming reduces S. litura larval sensitivity to insecticides remains largely unknown. This study was conducted to explore the potential of volatile from undamaged, or artificially damaged, or S. litura-damaged tomato plants on the susceptibility of S. litura to the insecticides beta-cypermethrin indoxacarb and chlorpyrifos. We found that larvae exposed to volatile from S. litura-damaged or artificially damaged tomato plants were significantly less susceptible to the three insecticides than those exposed to volatile from undamaged tomato plants. Elevated activities of detoxifying enzymes [cytochrome P450 monooxygenases (P450s), glutathione S-transferases (GSTs), and esterases (ESTs)], were expressed in S. litura larvae exposed to volatile from S. litura-damaged tomato plants than those exposed to volatile from undamaged tomato plants. Similarly, seven detoxification-related genes [GSTs (SlGSTe1, SlGSTo1, and SlGSTe3) and P450s (CYP6B48, CYP9A40, CYP321A7, and CYP321B1)] in the midgut and fat body of larvae were up-regulated under exposure to volatile from S. litura-damaged tomato plants. Increased volatile organic compounds emissions were detected in the headspace of tomato plants damaged by S. litura compared to the undamaged plants. Collectively, these findings suggest that HIPVs can considerably reduce caterpillar susceptibility to insecticides, possibly through induction-enhanced detoxification mechanisms, and provide valuable information for implementing an effective integrated pest management strategy.


Assuntos
Clorpirifos , Inseticidas , Solanum lycopersicum , Compostos Orgânicos Voláteis , Animais , Clorpirifos/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Esterases , Glutationa , Herbivoria , Inseticidas/toxicidade , Larva , Spodoptera , Transferases/farmacologia , Compostos Orgânicos Voláteis/farmacologia
9.
Environ Pollut ; 307: 119549, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35644429

RESUMO

Additives are considered a promising approach to accelerate the composting process and alleviate the dissemination of pollutants to the environment. However, nearly all previous articles have focused on the impact of additive amounts on the reduction of HMs, which may not fully represent the main factor shaping HMs bioavailability status during composting. Simultaneously, previous reviews only explored the impacts, speciation, and toxicity mechanism of HMs during composting. Hence, a global-scale meta-analysis was conducted to investigate the response patterns of HMs bioavailability and compost parameters to different additives, composting duration, and composting factors (additive types, feedstock, bulking agents, and composting methods) by measuring the weighted mean values of the response ratio "[ln (RR)]" and size effect (%). The results revealed that additives significantly lessened HMs bioavailability by ≥ 40% in the final compost products than controls. The bioavailability decline rates were -40%, -60%, -57%, -55%, -42%, and -44% for Zn, Pb, Ni, Cu, Cr, and Cd. Simultaneously, additives significantly improved the total nitrogen (TN) (+16%), pH (+5%), and temperature (+5%), and decreased total organic carbon (TOC) (-17%), moisture content (MC) (-18%), and C/N ratio (-19%). Furthermore, we found that the prolongation of composting time significantly promoted the effect of additives on declining HMs bioavailability (p < 0.05). Nevertheless, increasing additive amounts revealed an insignificant impact on decreasing the HMs bioavailability (p > 0.05). Eventually, using zeolite as an additive, chicken manure as feedstock, sawdust as a bulking agent, and a reactor as composting method had the most significant reduction effect on HMs bioavailability (p < 0.05). The findings of this meta-analysis may contribute to the selection, modification, and application of additives and composting factors to manage the level of bioavailable HMs in the compost products.


Assuntos
Compostagem , Metais Pesados , Disponibilidade Biológica , Esterco/análise , Metais Pesados/análise , Esgotos/química , Solo/química
10.
Environ Sci Pollut Res Int ; 29(42): 63423-63443, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35460008

RESUMO

Industrial upgrading is the key to promoting green economic efficiency. Coordination between environmental regulations and industrial structure can lead to sustainable economic growth. However, insufficient attention has been paid to the mechanism by which environmental regulation (ER) promote green economic efficiency (GEE) under the mediating role of industrial structure optimization. Using robust and comprehensive measures of green economic efficiency, we assess how various environmental regulations affect green economic efficiency as well as the intermediate effect of industrial structure of a certain province with provincial panel data during the period 2003-2017. The results of dynamic panel two-step system generalized method of moments (GMM) confirm the heterogeneous effects of the three types of ER, namely control-and-command regulation, market-based regulation, and voluntary regulation on GEE in China. The spatial analysis demonstrates that control-and-command and voluntary regulations significantly accelerate GEE in inland provinces, while they have insignificant effect in coastal provinces. Based on the mediating analysis, we find that market-based regulation is conducive to GEE through both advanced and rationalized industrial structure, whereas control-and-command regulation improves GEE through advanced industrial structure only. The voluntary-based regulation on one hand stimulates GEE through advanced industrial structure, but on other hand impedes it through rationalized industrial structure. The results could provide critical insights and a theoretical basis for policy makers in reasonable optimization of industrial structure and guaranteeing green economic efficiency.


Assuntos
Desenvolvimento Econômico , Indústrias , China , Eficiência
11.
Chemistry ; 27(64): 16049-16055, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34494672

RESUMO

Tetracyanobuta-1,3-diene (TCBD) is a powerful and versatile electron-acceptor moiety widely used for the preparation of electroactive conjugates. While many reports addressing its electron-accepting capability have appeared in the literature, significantly scarcer are those dealing with its chemical modification, a relevant topic which allows to broaden the chemical space of this interesting functional unit. Here, we report on the first example of a high-yielding cyano-Diels-Alder (CDA) reaction between TCBD, that is, where a nitrile group acts as a dienophile, and an anthryl moiety, that is, acting as a diene. The resulting anthryl-fused-TCBD derivative, which structure was unambiguously identified by X-ray diffraction, shows high thermal stability, remarkable electron-accepting capability, and interesting electronic ground- and excited-state features, as characterized by a thorough theoretical, electrochemical, and photophysical investigation. Moreover, a detailed kinetic analysis of the intramolecular CDA reaction transforming the anthryl-TCBD-based reactant into the anthryl-fused-TCBD product was carried out at different temperatures.

12.
Chemistry ; 27(68): 17181-17187, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34519409

RESUMO

The covalent attachment of molecular photosensitizers (PS) to polyoxometalates (POMs) opens new pathways to PS-POM dyads for light-driven charge-transfer and charge-storage. Here, we report a synthetic route for the covalent linkage of BODIPY-dyes to Anderson-type polyoxomolybdates by using CLICK chemistry (i. e. copper-catalyzed azide-alkyne cycloaddition, CuAAC). Photophysical properties of the dyad were investigated by combined experimental and theoretical methods and highlight the role of both sub-components for the charge-separation properties. The study demonstrates how CLICK chemistry can be used for the versatile linkage of organic functional units to molecular metal oxide clusters.


Assuntos
Química Click , Fármacos Fotossensibilizantes , Ânions , Azidas , Compostos de Boro , Polieletrólitos
13.
Pestic Biochem Physiol ; 178: 104946, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446184

RESUMO

Spodoptera litura (Fabricius) is a widely distributed, highly polyphagous pest that can cause severe damage to a variety of economically important crops. Various populations have developed resistance to different classes of insecticides. In this study, we report on two indoxacarb-resistant S. litura populations, namely Ind-R (resistance ratio = 18.37-fold) derived from an indoxacarb-susceptible (Ind-S) population and a population caught from a field (resistance ratio = 46.72-fold). A synergist experiment showed that piperonyl butoxide (PBO) combined with indoxacarb produced higher synergistic effects (synergist ratio = 5.29) in the Ind-R population as compared to Ind-S (synergist ratio = 3.08). Elevated enzyme activity of cytochrome P450 monooxygenases (P450s) was observed for Ind-R (2.15-fold) and the Field-caught population (4.03-fold) as compared to Ind-S, while only minor differences were noticed in the activities of esterases and glutathione S-transferases. Furthermore, expression levels of P450 genes of S. litura were determined by quantitative reverse transcription PCR to explore differences among the three populations. The results showed that the mRNA levels of CYP6AE68, a novel P450 gene belonging to the CYP6 family, were constitutively overexpressed in Ind-R (32.79-fold) and in the Field-caught population (68.11-fold). CYP6AE68 expression in S. litura was further analyzed for different developmental stages and in different tissues. Finally, we report that RNA interference-mediated silencing of CYP6AE68 increased the mortality of fourth-instar larvae exposed to indoxacarb at the LC50 dose level (increase by 33.89%, 29.44% and 22.78% for Ind-S, Ind-R and the Field-caught population, respectively). In conclusion, the findings of this study indicate that expression levels of CYP6AE68 in S. litura larvae are associated with indoxacarb resistance and that CYP6AE68 may play a significant role in detoxification of indoxacarb.


Assuntos
Inseticidas , Mariposas , Animais , Sistema Enzimático do Citocromo P-450/genética , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Larva/genética , Oxazinas/farmacologia , Spodoptera/genética
14.
Environ Sci Pollut Res Int ; 28(34): 46147-46160, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33415616

RESUMO

Based on the panel data of 30 provinces (except for Tibet, Hong Kong, Macao, and Taiwan) in China from 2005 to 2016, a nonlinear threshold regression model and a carbon emission expansion models were constructed to empirically analyze the threshold effect of inward foreign direct investment (IFDI) and outward foreign direct investment (OFDI) on carbon dioxide emission intensity in China. The results show that (1) China's OFDI has increased carbon dioxide emission intensity while the IFDI has a significant inhibitory effect on carbon dioxide emission intensity. (2) The impact of the OFDI on carbon dioxide emission intensity gets influenced by the threshold effect of population size, economic development level, technology level, and environmental regulation. (3) The impact of the IFDI on carbon dioxide emission intensity also has threshold characteristics affected by population size, economic development level, and technological level. Hence, China should introduce more IFDI, optimize the structure of the OFDI, and exert its environmental improvement effect to satisfy the carbon emission reduction goal earlier.


Assuntos
Dióxido de Carbono , Investimentos em Saúde , Dióxido de Carbono/análise , China , Desenvolvimento Econômico , Internacionalidade , Análise de Regressão
15.
Sci Total Environ ; 759: 143744, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33341514

RESUMO

Green innovation (GI) is an important way to realize the sustainable development. This paper contributes to the existing literature by analyzing the effects of different environmental regulations on green innovation from a heterogeneous perspective. We also compare the impacts of indigenous innovation input and foreign technology spillover on green innovation. The dataset of this paper covers a panel of China's 30 provinces from 2003 to 2017. The results of Systematic Generalized Method of Moments (SYS-GMM) show that command-and-control regulation (CER) and informal regulation (IER) have significant "Porter's effect" on green innovation while market-based regulation (MER) negatively affects green innovation in China. Inward foreign direct investment (IFDI) plays a positive role in developing China's green innovation thus, validating the "Pollution Halo hypothesis". Outward direct investment (OFDI) has a reverse green technique effect on China's green innovation. In addition, the positive effect of indigenous innovation input on green innovation is larger than that of foreign technology spillover from IFDI and OFDI. Moreover, the strengthening of CER weakens the positive effect of IFDI on green innovation. By contrast, the increase of IER can promote the reverse green technology spillover effect of OFDI on green innovation. On the basis of results, the government should attract green inward FDI and invest on foreign technology-intensive industries to obtain green technology spillover and stimulate green innovation.

16.
Chemistry ; 27(12): 4081-4088, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33241590

RESUMO

In this work, we present a new synthetic strategy for fourfold-substituted perylene monoimides via tetrabrominated perylene monoanhydrides. X-ray diffraction analysis unveiled the intramolecular stacking orientation between the substituents and semicircular packing behavior. We observed the remarkable influence of the substituent on the longevity and nature of the excited state upon visible light excitation. In the presence of poly(dehydroalanine)-graft-poly(ethylene glycol) graft copolymers as solubilizing template, the chromophores are capable of sensitizing [Mo3 S13 ]2- clusters in aqueous solution for stable visible light driven hydrogen evolution over three days.

17.
Chem Commun (Camb) ; 56(72): 10485-10488, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32766633

RESUMO

Understanding the limitations of catalytic processes enables the design of optimized catalysts. Here, femtosecond transient absorption spectroelectrochemistry is used to explore the photophysics of polyoxometalate-based covalent photosensitizer-hydrogen evolution catalyst dyads. The study shows that the presence of light-driven forward and backward electron transfer, i.e. "electron ping-pong", is a limiting factor for charge accumulation on the polyoxometalate. Based on this insight, chemical means of optimizing catalyst performance are proposed.

18.
Sci Total Environ ; 732: 139247, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438183

RESUMO

This study aimed to investigate the effects of nitrate on the ultraviolet (UV) treatment of simulated washing wastes containing Trion X-100 (TX-100) surfactant and 4,4'-dibromodiphenyl ether (BDE-15) pollutant. The presence of nitrate accelerated the photodegradation of BDE-15 and TX-100, because they reacted with reactive oxygen species (ROS) produced from conversion between nitrate and nitrite. Due to nitrite having a stronger radical quenching property than nitrate, nitrite hindered TX-100 decay while the photodegradation rate of BDE-15 was similar to that in the presence of nitrate. This indicated that nitrate/nitrite affected BDE-15 photodegradation by photosensitization and TX-100 loss by ROS attack. An increased TX-100 concentration increased the loss of total inorganic nitrogen possibly owing to an increase in organic nitrogen formation through TX-100 nitration reactions. At pH < 7 HOONO rapidly isomerized to NO3-, and at pH = 7-9 it homolyzed to ONOO-, which increased OH production to decay the BDE-15 and TX-100 and also increased NO2- formation. BDE-15 mainly underwent debromination, and some rearrangement, ring formation, nitration and hydroxylation products were detected, indicating that the produced OH and NO2 attacked the BDE-15 and products. Furthermore, broken-chain, carboxylation, hydroxylation and nitro products were detected by Liquid chromatography high resolution mass spectrometry (LC-HRMS). Escherichia coli was used to assess the toxicity of washing waste containing nitrate: the presence of nitrate will increase the wastes' toxicity during UV treatment. Therefore, the presence of nitrate is deleterious to the UV treatment of washing wastes, and it is important to remove nitrates and nitrites from washing waste before UV irradiation.


Assuntos
Nitratos/análise , Éteres Difenil Halogenados , Cinética , Nitritos , Octoxinol
19.
Chemistry ; 26(36): 8045-8052, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32237163

RESUMO

Covalently linked photosensitizer-polyoxometalate (PS-POM) dyads are promising molecular systems for light-induced energy conversion processes, such as "solar" hydrogen generation. To date, very little is known of their fundamental photophysical properties which affect the catalytic reactivity and stability of the systems. PS-POM dyads often feature short-lived photoinduced charge-separated states, and the lifetimes of these states are considered crucial for the function of PS-POM dyads in molecular photocatalysis. Hence, strategies have been developed to extend the lifetimes of the photoinduced charge-separated states, either by tuning the PS photophysics or by tuning the POM redox properties. Recently, some of us reported PS-POM dyads based on cyclometalated IrIII complexes covalently linked to Anderson-type polyoxometalate. Distinct hydrogen evolution reactivity (HER) of the dyads was observed, which was tuned by varying the central metal ion M of the POMM (M=Mn3+ , Co3+ , Fe3+ ). In this manuscript, the photoinduced electron-transfer processes in the three Ir-POMM dyads are investigated to rationalize the underlying reasons for the differences in HER activity observed. We report that upon excitation of the IrIII complex, ultrafast (sub-ps) charge separation occurs, leading to different amounts of the charge-separated states (Ir.+ -POMM .- ) generated in the different dyads. However, in all dyads studied, the resulting Ir.+ -POMM .- species are short-lived (sub-ns) when compared to reference electron acceptors (e.g. porphyrins or fullerenes) reported in the literature. The reductive quenching of Ir.+ -POMM .- by a sacrificial donor, triethyl amine (1 m), to generate the intermediate Ir-POMM .- is estimated to be very efficient (70-80 %) for all dyads studied. Based on this analyses, we conclude that the yield instead of the lifetime of the Ir.+ -POMM .- charge-separated state determines the catalytic capacity of the dyads investigated. This new feature in the PS-POM photophysics could lead to new design criteria for the development of novel PS-POM dyads.

20.
Chem Commun (Camb) ; 55(36): 5251-5254, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-30990492

RESUMO

Photoinduced electron transfer via hopping is generally considered to have a stronger temperature dependence than electron transfer via superexchange. However, in this work, an opposite trend of the temperature dependence is observed. This unexpected result is rationalized by considering the specific geometrical and electronic structure of the Ru-bis(terpyridine) photosensitizer.

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