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1.
Mikrochim Acta ; 191(5): 277, 2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38647714

RESUMEN

Widely used organophosphorus pesticide triazophos (TAP) can easily cumulate in aquatic system due to its high stability chemically and photochemically and thus posing significant threat to aquatic creatures and humans' health. Urging demand for rapid determining TAP in water has risen. Photoelectrochemical (PEC) sensing turns out to be a good candidate for its simplicity in fabrication and swiftness in detection. Nevertheless, traditional PEC sensors often lack selectivity as their signal generation primarily relies on the oxidation of organic compounds in the electrolyte by photo-induced holes. To address this limitation, molecularly imprinted polymers (MIPs) can be in combined with PEC sensors to significantly enhance the selectivity. Here, we present a novel approach utilizing a PEC sensor enhanced by carbon-modified titanium dioxide molecularly imprinted polymers (MIP/C/TiO2 NTs). Carbon quantum dot (CQD) modification of titanium dioxide nanotube arrays (C/TiO2 NTs) was achieved through a one-step anodization process, effectively enhancing visible light absorption by narrowing the band gap of TiO2, and CQDs also function as sensitizer accelerating charge transfer for improved and stable photocurrent signals during detection. Our method further incorporates MIPs to heighten the selectivity of the PEC sensor. Electro-polymerization using cyclic voltammetry was employed to polymerize MIPs with pyrrole as the functional monomer and triazophos as the target molecule. The resultant MIP/C/TiO2 NT sensor exhibited remarkable sensitivity, with a detection limit of 0.03 nM (S/N = 3), alongside exceptional selectivity and stability for triazophos detection in water. This offers a promising avenue for efficient, cost-effective, and rapid monitoring of pesticide contaminants in aquatic environments, contributing to the broader goals of environmental preservation and public health.

2.
Chemistry ; 29(19): e202203787, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-36585826

RESUMEN

Zinc-air batteries (ZABs) have been considered as one of the most promising energy storage devices to solve the problem of energy crisis and environmental pollution. In this work, we reported the synthesis of nitrogen-doped MnO2 (N-MnO2 ) to replace the noble metal electrocatalysts for air cathode in ZABs. The doped N atoms here introduced more Mn3+ and oxygen vacancies for MnO2 , enhancing charge transfer property and accelerating surface intermediate product during the oxygen reduction reaction (ORR). Hence, the best N-MnO2 achieved remarkable electrocatalytic activities towards ORR (half-wave potential of 0.797 V vs. RHE), and reversible oxygen overpotential of around 0.842 V, which is better than or comparable to the Pt/C and Mn-based catalysts reported recently. Moreover, the homemade ZABs based on N-MnO2 showed the maximum power density of 132.8 mW cm-2 and excellent cyclic stability.

3.
Mikrochim Acta ; 190(6): 244, 2023 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-37247003

RESUMEN

A photoelectrochemical molecular imprinting sensor based on Au/TiO2 nanocomposite was constructed for the detection of dibutyl phthalate. Firstly, TiO2 nanorods were grown on fluorine-doped tin oxide substrate by hydrothermal method. Then, gold nanoparticles were electrodeposited on TiO2 to fabricate Au/TiO2. Finally, molecular imprinted polymer was electropolymerized on the Au/TiO2 surface to construct MIP/Au/TiO2 PEC sensor for DBP. The conjugation effect of MIP accelerates the electron transfer between TiO2 and MIP, which can greatly improve the photoelectric conversion efficiency and sensitivity of the sensor. In addition, MIP can also provide sites for highly selective recognition of dibutyl phthalate molecules. Under optimal experimental conditions, the prepared photoelectrochemical sensor was used for the quantitative determination of DBP and the results showed a wide linear range (50 to 500 nM), a low limit of detection (0.698 nM), and good selectivity. The sensor was used in a study of real water samples to show that it has promising applications in environmental analysis.

4.
Mikrochim Acta ; 189(12): 453, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36411347

RESUMEN

A photoelectrochemical (PEC) aptasensor based on CdSe@SnS2 nanocomposite has been developed to detect sulfamethazine (SMZ). The introduction of CdSe into SnS2 displayed an amplified PEC signal, which was higher than that of pure CdSe and SnS2, attributable to its enhanced light harvesting capacity and promoted PEC energy conversion efficiency. Due to the formation of specific non-covalent bonds, the SMZ-binding aptamer (SBA) has significant specificity and sensitivity. When SMZ was incubated on a CdSe@SnS2 modified electrode fixed with aminated SBA, the formation of the SMZ/SBA complex increased the space resistance of electron transfer and hindered the electronic migration between the electrodes, resulting in a decrease in photocurrent. The greater the adsorbed amount on the SBA, the lower the photocurrent produced.  Under optimized conditions the photocurrent response of MCH/SBA/CdSe@SnS2/FTO was inversely proportional to the SMZ concentration in the range 0.1 to 100 pM, with a detection limit (3 S/N) of 0.025 pM (at 0 V vs. Hg/HgCl). The recoveries ranged from 95.8 to 104% with relative standard deviations (RSDs) < 6.3% (n = 3) in actual water sample. This PEC aptasensor which shows considerable potential in SMZ detection applications has high selectivity, reproducibility, and good stability.


Asunto(s)
Técnicas Biosensibles , Compuestos de Cadmio , Nanocompuestos , Compuestos de Selenio , Sulfametazina , Compuestos de Cadmio/química , Técnicas Electroquímicas/métodos , Técnicas Biosensibles/métodos , Reproducibilidad de los Resultados , Titanio/química , Compuestos de Selenio/química , Nanocompuestos/química
5.
J Proteome Res ; 18(6): 2478-2492, 2019 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-31038978

RESUMEN

Chlorophyll is a vital photosynthetic pigment that plays a key role in plant development, participating in light energy capture and energy conversion. In this study, a novel wucai ( Brassica campestris L.) germplasm with green outer leaves and yellow inner leaves at the adult stage (W7-2) was used to examine chlorophyll metabolism response to cold acclimation. A green leaf wucai genotype without leaf color changes named W7-1 was selected as the control to evaluate the chlorophyll metabolism changes of W7-2. Compared to W7-1, the contents of chlorophyll a (Chl a) and chlorophyll b (Chl b) in W7-2 were significantly reduced at five developmental stages (13, 21, 29, 37, and 45 days after planting (DAP)). An iTRAQ-based quantitative proteomic analysis was carried out at 21 and 29 DAP according to the leaf color changes in both of genotypes. 1409 proteins were identified, while 218 of them displayed differential accumulations between W7-2 and W7-1 during the two developmental stages. The differentially expressed proteins (DEPs) mainly assigned to chlorophyll biosynthesis, photosynthesis, carbohydrate metabolism, ribosome metabolism and posttranslational modification. Among these DEPs, NADPH-protochlorophyllide oxidoreductase (PORB) and Mg-protoporphyrin IX chelatase 1 (CHLI1) were the key enzymes participating in chlorophyll (Chl) biosynthesis, which was down-regulated at 21 DAP and up-regulated at 29 DAP in W7-2 compared with W7-1, respectively. The expression analysis of genes of three subunits of Mg-chelatase ( CHLI1, CHLD, and CHLH), Genomes Uncoupled 4 ( GUN4), and Thioredoxin ( TRX3) associated with chlorophyll metabolism also displayed significant down-regulation in W7-2. In particular, PORB showed significant up-regulation in W7-2, significantly affecting chlorophyll biosynthesis. Additionally, differences in chlorophyll metabolism between W7-2 and W7-1 were in terms of altered photosynthesis, carbohydrate, and energy metabolism. We found that the transcription levels of most photosynthesis proteins showed significantly lower levels, and the genes expression level, associated with carbohydrate and energy metabolism, were lower in W7-2 than in W7-1. Therefore, the present study results help understand the physiological and molecular mechanisms underlying leaf coloring responding to cold acclimation.


Asunto(s)
Aclimatación/genética , Brassica/genética , Hojas de la Planta/genética , Proteómica , Brassica/crecimiento & desarrollo , Clorofila/genética , Clorofila/metabolismo , Clorofila A/genética , Clorofila A/metabolismo , Frío , Pigmentos Biológicos/genética , Hojas de la Planta/crecimiento & desarrollo
6.
BMC Genomics ; 20(1): 810, 2019 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-31694527

RESUMEN

BACKGROUND: Brassinosteroids (BRs) have a positive effect on many processes during plant growth and development, and in response to various abiotic stressors. Low-temperature (LT) stress constricts the geographic distribution, growth, and development of wucai (Brassica campestris L. ssp. chinensis var. rosularis Tsen). However, there is little information on the global gene expression of BRs under LT stress in wucai. In this study, the molecular roles of 24-epibrassinolide (EBR) after exogenously application, were explored by RNA sequencing under LT conditions. RESULTS: According to the Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, photosynthesis was significantly enriched after spraying EBR under LT. The transcripts encoding the photosystem II (PSII) oxygen-evolving enhancer protein, photosystem I (PSI) subunit, light-harvesting chlorophyll protein complexes I and II, and ferredoxin were up-regulated after the application of EBR. Transcripts encoding several key enzymes involved in chlorophyll biosynthesis were also up-regulated, accompanied by significant differences in the contents of 5-aminolevulinic acid (ALA), porphobilinogen (PBG), protoporphyrin IX (Proto IX), Mg-protoporphyrin IX (Mg-proto IX), protochlorophyllide (Pchl), and photosynthetic pigments. Notably, transcriptional and physiological analyses revealed that under LT stress, plant responses to EBR involved a major reorientation of photosynthesis, as well as porphyrin and chlorophyll metabolism. CONCLUSION: This study explored the role of EBR as an LT stress tolerance mechanism in wucai. At the transcription level, LT tolerance manifests as an enhancement of photosynthesis, and the amelioration of porphyrin and chlorophyll metabolism.


Asunto(s)
Brassica/genética , Brassica/metabolismo , Brasinoesteroides/farmacología , Respuesta al Choque por Frío/genética , Perfilación de la Expresión Génica , Fotosíntesis/efectos de los fármacos , Brassica/efectos de los fármacos , Brassica/fisiología , Esteroides Heterocíclicos/farmacología
7.
Org Biomol Chem ; 17(4): 892-897, 2019 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-30629064

RESUMEN

At the density functional theory (DFT) level, addition reactions between the guanine-8-yl radical and its 3'/5' neighboring purine deoxynucleosides forming the purine-purine type intrastrand cross-links were studied. It is found that addition of the guanine-8-yl radical to the C8 site of its 5' neighboring deoxyguanosine or deoxyadenosine is a two-step reaction consisting of a structurally relatively unfavourable conformational transformation step, while the corresponding 3' C8 addition is straightforward and kinetically more efficient. The 3' C8 preference of the guanine-8-yl radical additions indicates the existence of an obvious sequence effect, which is completely opposite to that observed in the formation of pyrimidine radicals induced DNA intrastrand cross-links. The detrimental effects from steric hindrance and stabilizing weak interactions make these addition reactions markedly suppressed in double stranded DNA. This work broadens our knowledge about the possible types of DNA intrastrand cross-links.

8.
Int J Mol Sci ; 20(15)2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31374822

RESUMEN

The genotype WS-1, previously identified from novel wucai germplasm, is tolerant to both low-temperature (LT) and high-temperature (HT) stress. However, it is unclear which signal transduction pathway or acclimation mechanisms are involved in the temperature-stress response. In this study, we used the proteomic method of tandem mass tag (TMT) coupled with liquid chromatography-mass spectrometry (LC-MS/MS) to identify 1022 differentially expressed proteins (DEPs) common to WS-1, treated with either LT or HT. Among these 1022 DEPs, 172 were upregulated in response to both LT and HT, 324 were downregulated in response to both LT and HT, and 526 were upregulated in response to one temperature stress and downregulated in response to the other. To illustrate the common regulatory pathway in WS-1, 172 upregulated DEPs were further analyzed. The redox homeostasis, photosynthesis, carbohydrate metabolism, heat-shockprotein, and chaperones and signal transduction pathways were identified to be associated with temperature stress tolerance in wucai. In addition, 35S:BcccrGLU1 overexpressed in Arabidopsis, exhibited higher reduced glutathione (GSH) content and reduced glutathione/oxidized glutathione (GSH/GSSG) ratio and less oxidative damage under temperature stress. This result is consistent with the dynamic regulation of the relevant proteins involved in redox homeostasis. These data demonstrate that maintaining redox homeostasis is an important common regulatory pathway for tolerance to temperature stress in novel wucai germplasm.


Asunto(s)
Brassica/fisiología , Termotolerancia , Brassica/genética , Respuesta al Choque por Frío , Regulación de la Expresión Génica de las Plantas , Respuesta al Choque Térmico , Homeostasis , Oxidación-Reducción , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Mapas de Interacción de Proteínas , Proteómica
9.
Mikrochim Acta ; 186(1): 21, 2018 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-30554349

RESUMEN

The authors describe a simplified chemical precipitation method and silver mirror reaction to synthesize a nanocomposite consiting of silver nanoparticles on a thin and porous nickel oxide film. Placed on a glassy carbon electrode (GCE), it allows for the determination of levofloxacin (LEV) via square wave voltammetry (SWV). Under optimal detection conditions, the voltammetric signal (typically measured at around 0.96 V vs. SCE) increases linearly in the 0.25-100 µM LEV concentration range. And the detection limit was calculated as 27 nM (at S/N = 3). The sensor is highly selective, stable and repeatable. It was applied to the determination of LEV in spiked human serum samples, and the satisfactory results confirm the applicability of this sensor to practical analyses. Graphical abstract Schematic of a two-step method to synthesize a nanocomposite consisting of nickel oxide porous thin-film supported silver nanoparticles. The composite was used for improved voltammetric determination of levofloxacin.


Asunto(s)
Antibacterianos/sangre , Técnicas Electroquímicas/métodos , Levofloxacino/sangre , Nanopartículas del Metal/química , Níquel/química , Plata/química , Técnicas Biosensibles/métodos , Electrodos , Humanos , Concentración de Iones de Hidrógeno , Límite de Detección , Nanocompuestos/química , Porosidad
10.
Chemistry ; 23(40): 9625-9631, 2017 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-28510292

RESUMEN

The development for hydrogen from solar energy has attracted great attention due to the global demand for clean, environmentally friendly energy. Herein, autologous Cd/CdO/CdS heterojunctions were prepared in a carefully controlled process with metallic Cd as the inner layer and CdO as the interlayer. Further research revealed that the transportation and separation of photogenerated pairs were enhanced due to low resistance of the Cd inner layer and the type II CdO/CdS heterojunction. As a result, the optimized Cd/CdO/CdS heterojunction photoanode showed outstanding and long-term photoelectrochemical activity for water splitting, with a current density of 3.52 mA cm-2 , or a benchmark specific hydrogen production rate of 1.65 µmol cm-2 min-1 at -0.3 V versus Ag/AgCl, by using the environmental pollutants of sulfide and sulfite as sacrificial agents.

11.
Phys Chem Chem Phys ; 19(42): 28907-28916, 2017 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-29057416

RESUMEN

Pyrimidine-type radicals have been demonstrated to be able to attack their 3' or 5' neighboring purine nucleotides forming diverse DNA intrastrand cross-links, but whether or not these radicals can attack their surrounding pyrimidine nucleotides forming pyrimidine-pyrimidine type DNA intrastrand cross-links remains unclear. To resolve this question, probable additions of the uracil-5-methyl (˙UCH2) radical to the C5[double bond, length as m-dash]C6 double bond of its 3'/5' neighboring pyrimidine nucleotides in the four models, 5'-T(˙UCH2)-3', 5'-C(˙UCH2)-3', 5'-(˙UCH2)T-3', and 5'-(˙UCH2)C-3', are explored in the present work employing density functional theory (DFT) methods. The C6 site of its 5' neighboring thymidine is the preferred target for ˙UCH2 radical addition, while additions of the ˙UCH2 radical to the C6 and C5 sites of its 5' neighboring deoxycytidine are found to be competitive reactions. The ˙UCH2 radical can react with both the C6 and C5 sites of its 3' neighboring pyrimidine nucleotides, but the efficiencies of these reactions are predicted to be much lower than those of the corresponding addition reactions to its 5' neighboring pyrimidine nucleotides, indicating the existence of an obvious sequence effect. All the addition products could be finally transformed into closed-shell intrastrand cross-links, the molecular masses of which are found to be exactly the same as certain MS values determined in a recent study of an X-irradiated deoxygenated aqueous solution of calf thymus DNA. The present study thus not only definitely corroborates the fact that the reactive ˙UCH2 radical can attack its 3'/5' neighboring pyrimidine nucleotides forming several pyrimidine-pyrimidine type DNA intrastrand cross-links, but also provides a plausible explanation for the identities of these structurally unknown intrastrand cross-links.


Asunto(s)
Daño del ADN , ADN/química , Pirimidinas/química , Animales , Bovinos , Uracilo
12.
Phys Chem Chem Phys ; 19(25): 16621-16628, 2017 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-28617503

RESUMEN

Currently, all known DNA intrastrand cross-links are found to be induced by pyrimidine-type radicals; however, whether or not purine-type radicals are able to cause DNA intrastrand cross-links remains unclear. In the present study, probable additions of the highly reactive deoxyguanosine-8-yl radical to its 3'/5' neighboring pyrimidine nucleotides in four model compounds, 5'-G˙T-3', 5'-TG˙-3', 5'-G˙C-3', and 5'-CG˙-3', were studied using density functional theory (DFT) methods. In single-stranded DNA, the deoxyguanosine-8-yl radical is preferred to efficiently attack the C5 site of its 3' neighboring deoxythymidine or deoxycytidine, forming the G[8-5]T or G[8-5]C intrastrand cross-link rather than the C6 site forming the G[8-6]T or G[8-6]C intrastrand cross-link. The four corresponding sequence isomers, namely T[5-8]G, T[6-8]G, C[5-8]G, and C[6-8]G, formed by additions of deoxyguanosine-8-yl radical to its 5' neighboring pyrimidine nucleotides are predicted to be formed inefficiently. In double-stranded DNA, considering the detrimental effects of stabilizing weak interactions on related structural adjustments required in each addition reaction path, relatively lower reaction yields are suggested for the G[8-5]T and G[8-5]C intrastrand cross-links, while the formation of the other six intrastrand cross-links becomes quite difficult. All calculations definitely demonstrate that, in addition to pyrimidine-type radicals, the purine-type deoxyguanosine-8-yl radical is able to attack its 3'/5' neighboring pyrimidine nucleotides forming several DNA intrastrand cross-links.


Asunto(s)
Aductos de ADN/química , ADN/química , Desoxiguanosina/química , Radicales Libres/química , Modelos Moleculares , Conformación Molecular , Purinas/química , Teoría Cuántica
14.
Chem Soc Rev ; 43(22): 7581-93, 2014 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-24599050

RESUMEN

Hydrogen, a clean energy carrier with high energy capacity, is a very promising candidate as a primary energy source for the future. Photoelectrochemical (PEC) hydrogen production from renewable biomass derivatives and water is one of the most promising approaches to producing green chemical fuel. Compared to water splitting, hydrogen production from renewable biomass derivatives and water through a PEC process is more efficient from the viewpoint of thermodynamics. Additionally, the carbon dioxide formed can be re-transformed into carbohydrates via photosynthesis in plants. In this review, we focus on the development of photoanodes and systems for PEC hydrogen production from water and renewable biomass derivatives, such as methanol, ethanol, glycerol and sugars. We also discuss the future challenges and opportunities for the design of the state-of-the-art photoanodes and PEC systems for hydrogen production from biomass derivatives and water.


Asunto(s)
Biomasa , Hidrógeno/química , Agua/química , Técnicas Electroquímicas , Electrodos , Etanol/química , Etanol/metabolismo , Glicerol/química , Glicerol/metabolismo , Metanol/química , Metanol/metabolismo , Polisacáridos/química , Polisacáridos/metabolismo , Energía Solar
15.
Nano Lett ; 13(6): 2628-33, 2013 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-23634667

RESUMEN

To push the energy density limit of asymmetric supercapacitors (ASCs), a new class of anode materials is needed. Vanadium nitride (VN) holds great promise as anode material for ASCs due to its large specific capacitance, high electrical conductivity, and wide operation windows in negative potential. However, its poor electrochemical stability severely limits its application in SCs. In this work, we demonstrated high energy density, stable, quasi-solid-state ASC device based on porous VN nanowire anode and VOx nanowire cathode for the first time. The VOx//VN-ASC device exhibited a stable electrochemical window of 1.8 V and excellent cycling stability with only 12.5% decrease of capacitance after 10,000 cycles. More importantly, the VOx//VN-ASC device achieved a high energy density of 0.61 mWh cm(-3) at current density of 0.5 mA cm(-2) and a high power density of 0.85 W cm(-3) at current density of 5 mA cm(-2). These values are substantially enhanced compared to most of the reported quasi/all-solid-state SC devices. This work constitutes the first demonstration of using VN nanowires as high energy anode, which could potentially improve the performance of energy storage devices.

16.
Nat Commun ; 15(1): 302, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38182604

RESUMEN

Structure deterioration and side reaction, which originated from the solvated H2O, are the main constraints for the practical deployment of both cathode and anode in aqueous Zn-ion batteries. Here we formulate a weakly solvating electrolyte to reduce the solvating power of H2O and strengthen the coordination competitiveness of SO42- to Zn2+ over H2O. Experiment results and theoretical simulations demonstrate that the water-poor solvation structure of Zn2+ is achieved, which can (i) substantially eliminate solvated-H2O-mediated undesirable side reactions on the Zn anode. (ii) boost the desolvation kinetics of Zn2+ and suppress Zn dendrite growth as well as structure aberration of the cathode. Remarkably, the synergy of these two factors enables long-life full cells including Zn/NaV3O8·1.5H2O, Zn/MnO2 and Zn/CoFe(CN)6 cells. More importantly, practical rechargeable AA-type Zn/NVO cells are assembled, which present a capacity of 101.7 mAh and stability of 96.1% capacity retention after 30 cycles at 0.66 C.

17.
Anal Chim Acta ; 1303: 342512, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38609275

RESUMEN

BACKGROUND: Various surface-enhanced Raman spectroscopy (SERS) substrate preparation methods have been reported, however, how to tune the "gap" between nanostructures to make more "hot spots" is still a barrier that restricts their application. The gap between nanostructures is usually fixed when the substrates are prepared. In other words, it is hard to tune interparticle distances for maximum electromagnetic coupling during substrate preparation process. Therefore, an in-situ substrate optimization method that could monitor the SERS signal intensity changes, i.e., to find the optimum gap width and particle size, during substrate preparation process is needed. RESULTS: A method based on the galvanic replacement reaction (GRR) is proposed for the in-situ gap width tuning between nanostructures as well as for the optimization of SERS substrates. Noble metal nanoparticles (NPs) form and grow on the sacrificial templates' surface while noble metal ions are reduced by sacrificial metal (oxides) in GRR. Along with the fresh and clean NPs' surface generated, the gap between two noble metal NPs decreases with the growth of the NPs. To demonstrate this strategy, cuprous oxide/Ti (Cu2O/Ti) sacrificial templates were prepared, and then a GRR was carried out with HAuCl4. The real-time SERS detection during GRR show that the optimum reaction time (ORT) is 300 ± 30 s. Furthermore, SERS performance testing was conducted on the optimized substrate, revealing that the detection limit for crystal violet can reach 1.96 × 10-11 M, confirming the feasibility of this method. SIGNIFICANCE AND NOVELTY: By monitoring the in-situ SERS signal of probes during GRR will obtain an "optimal state" of the SERS substrate with optimal gap width and particle size. The SERS substrate preparation and optimization strategy proposed in this article not only provides a simple, efficient, and low-cost method to fabricate surface-clean noble NPs but also paves the way for the in-situ optimization of NPs size and gap width between NPs which could achieve wider applications of SERS.

18.
Nano Lett ; 12(10): 5376-81, 2012 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-22947093

RESUMEN

Metal nitrides have received increasing attention as electrode materials for high-performance supercapacitors (SCs). However, most of them are suffered from poor cycling stability. Here we use TiN as an example to elucidate the mechanism causing the capacitance loss. X-ray photoelectron spectroscopy analyses revealed that the instability is due to the irreversible electrochemical oxidation of TiN during the charging/discharging process. Significantly, we demonstrate for the first time that TiN can be stabilized without sacrificing its electrochemical performance by using poly(vinyl alcohol) (PVA)/KOH gel as the electrolyte. The polymer electrolyte suppresses the oxidation reaction on electrode surface. Electrochemical studies showed that the TiN solid-state SCs exhibit extraordinary stability up to 15,000 cycles and achieved a high volumetric energy density of 0.05 mWh/cm(3). The capability of effectively stabilizing nitride materials could open up new opportunities in developing high-performance and flexible SCs.

19.
Artículo en Inglés | MEDLINE | ID: mdl-37913551

RESUMEN

The recycling of spent graphite from waste lithium-ion batteries (LIBs) holds great importance in terms of environmental protection and conservation of natural resources. In this study, a simple two-step method involving heat treatment and solution washing was employed to recycle spent graphite. Subsequently, the recycled graphite was milled with red phosphorus to create a carbon/red phosphorus composite that served as an anode material for the new LIBs, aiming to address the low capacity issue. In a half-cell configuration, the carbon/red phosphorus composite exhibited remarkable cycling stability, maintaining a capacity of 721.7 mAh g-1 after 500 cycles at 0.2 A g-1, and demonstrated an excellent rate performance with a capacity of 276.2 mAh g-1 at 3 A g-1. The improved performance can be attributed to the structure of the composite, where the red phosphorus particles are covered by the carbon layer. This composite outperformed pure recycled graphite, highlighting its potential in enhancing the electrochemical properties of LIBs. Furthermore, when the carbon/red phosphorus composite was assembled into a full-cell configuration with LiCoO2 as the cathode material, it displayed a stable electrochemical performance, further validating its practical applicability. This work presents a promising and green strategy for recycling spent graphite and using it in the production of new batteries. The findings offer a high potential for commercialization, contributing to the advancement of sustainable and ecofriendly energy storage technologies.

20.
Langmuir ; 28(28): 10558-64, 2012 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-22697427

RESUMEN

We report the synthesis of Zn(x)Cd(1-x)S@ZnO nanorod arrays via a facile two-step process and the implementation of these core-shell nanorods as an environmental friendly and recyclable photocatalyst for methyl orange degradation. The band gap of Zn(x)Cd(1-x)S@ZnO core-shell nanorods can be readily tunable by adjusting the ratio of Zn/Cd during the synthesis. These Zn(x)Cd(1-x)S@ZnO core-shell nanorods exhibit a high photocatalytic activity and good stability in the degradation of the methyl orange. Moreover, these films grown on FTO substrates make the collection and recycle of the photocatalyst easier. These findings may open new opportunities for the design of effective, stable, and easy-recyclable photocatalytic materials.

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