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1.
Langmuir ; 40(17): 9020-9027, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38632903

RESUMO

We prepared BiOCl, BiO(ClBr), BiO(ClBrI), and BiO[ClBrI(CO3)0.5] materials using a simple coprecipitation method. It was found that adjusting the number of anions in the anion layer was conducive to adjusting the band structure of BiOX and could effectively promote the migration and separation of photogenerated carriers, thus improving the photocatalytic activity. We first selected methyl orange (MO) as the study pollutant and compared it with BiOCl, BiO(ClBr), and BiO(ClBrI). The first-order kinetic constants of MO degradation by BiO[ClBrI(CO3)0.5] increased by 90.3, 33.9, and 3.1 times, respectively. The photocatalytic degradation rate of methylene blue by BiO[ClBrI(CO3)0.5] was 89.5%, indicating the excellent photocatalytic performance of BiO[ClBrI(CO3)0.5]. The stability of BiO[ClBrI(CO3)0.5] was demonstrated through cyclic experiments and XRD analysis before and after the reaction. The photocatalytic degradation of MO by BiO[ClBrI(CO3)0.5] showed that h+ and 1O2 were the main active oxidizing species and •O2- was the secondary active substance. Overall, our work provides new ideas for the synthesis and degradation of organic pollutants by using two-dimensional anionic high-entropy materials.

2.
Langmuir ; 40(3): 1848-1857, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38183664

RESUMO

Elaborating the specific reactive oxygen species (ROS) involved in the photocatalytic degradation of atrazine (ATZ) is of great significance for elucidating the underlying mechanism. This study provided conclusive evidence that hydroxyl radicals (·OH) were the primary ROS responsible for the efficient photocatalytic degradation of ATZ, thereby questioning the reliability of widely adopted radical quenching techniques in discerning authentic ROS species. As an illustration, oxygen-modified g-C3N4 (OCN) was prepared to counteract the limitations of pristine g-C3N4 (CN). Comparative assessments between CN and OCN revealed a remarkable 10.44-fold improvement in the photocatalytic degradation of ATZ by OCN. This enhancement was ascribed to the increased content of C-O functional groups on the surface of the OCN, which facilitated the conversion of superoxide radicals (·O2-) into hydrogen peroxide (H2O2), subsequently leading to the generation of ·OH. The increased production of ·OH contributed to the efficient dealkylation, dechlorination, and hydroxylation of ATZ. Furthermore, toxicity assessments revealed a significant reduction in ATZ toxicity following its photocatalytic degradation by OCN. This study sheds light on the intricate interconversion of ROS and offers valuable mechanistic insights into the photocatalytic degradation of ATZ.

3.
Angew Chem Int Ed Engl ; 63(21): e202315802, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38453646

RESUMO

The development of nonpyrolytic catalysts featuring precisely defined active sites represents an effective strategy for investigating the fundamental relationship between the catalytic activity of oxygen reduction reaction (ORR) catalysts and their local coordination environments. In this study, we have synthesized a series of model electrocatalysts with well-defined CoN4 centers and nonplanar symmetric coordination structures. These catalysts were prepared by a sequential process involving the chelation of cobalt salts and 1,10-phenanthroline-based ligands with various substituent groups (phen(X), where X=OH, CH3, H, Br, Cl) onto covalent triazine frameworks (CTFs). By modulating the electron-donating or electron-withdrawing properties of the substituent groups on the phen-based ligands, the electron density surrounding the CoN4 centers was effectively controlled. Our results demonstrated a direct correlation between the catalytic activity of the CoN4 centers and the electron-donating ability of the substituent group on the phenanthroline ligands. Notably, the catalyst denoted as BCTF-Co-phen(OH), featuring the electron-donating OH group, exhibited the highest ORR catalytic activity. This custom-crafted catalyst achieved a remarkable half-wave potential of up to 0.80 V vs. RHE and an impressive turnover frequency (TOF) value of 47.4×10-3 Hz at 0.80 V vs. RHE in an alkaline environment.

4.
Angew Chem Int Ed Engl ; 63(14): e202319216, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38337143

RESUMO

The synthesis of hydrogen peroxide through artificial photosynthesis is a green and promising technology with advantages in sustainability, economy and safety. However, superoxide radical (⋅O2 -), an important intermediate in photocatalytic oxygen reduction to H2O2 production, has strong oxidizing properties that potentially destabilize the catalyst. Therefore, avoiding the accumulation of ⋅O2 - for its rapid conversion to H2O2 is of paramount significance in improving catalyst stability and H2O2 yield. In this work, a strategy was developed to utilize protonated groups for the rapid depletion of converted ⋅O2 -, thereby the efficiency of photocatalytic synthesis of H2O2 from CN was successfully enhanced by 47-fold. The experimental findings demonstrated that polydopamine not only improved carrier separation efficiency, and more importantly, provided the adsorption reduction active site for ⋅O2 - for efficient H2O2 production. This work offers a versatile approach for synthesizing efficient and stable photocatalysts.

5.
J Am Chem Soc ; 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37022925

RESUMO

Restrained by the uncontrollable cleavage process of chemical bonds in methane molecules and corresponding formed intermediates, the target product in the reaction of methane selective oxidation to methanol would suffer from an inevitable overoxidation process, which is considered to be one of the most challenging issues in the field of catalysis. Herein, we report a conceptually different method for modulating the conversion pathway of methane through the selective cleavage of chemical bonds in the key intermediates to suppress the generation of peroxidation products. Taking metal oxides, typical semiconductors in the field of methane oxidation as model catalysts, we confirm that the cleavage of different chemical bonds in CH3O* intermediates could greatly affect the conversion pathway of methane, which has a vital role in product selectivity. Specifically, it is revealed that the formation of peroxidation products could be significantly prevented by the selective cleavage of C-O bonds in CH3O* intermediates instead of metal-O bonds, which is proved by the combination of density functional theory calculations and in situ infrared spectroscopy based on isotope labeling. By manipulating the lattice oxygen mobility of metal oxides, the electrons transferring from the surface to the CH3O* intermediates could directionally inject into the antibonding orbitals of the C-O bond, resulting in its selective cleavage. As a result, the gallium oxide with low lattice oxygen mobility shows a 3.8% conversion rate for methane with a high methanol generation rate (∼325.4 µmol g-1 h-1) and selectivity (∼87.0%) under room temperature and atmospheric pressure in the absence of extra oxidants, which is superior among the reported studies (reaction pressure: <20 bar).

6.
Nanotechnology ; 34(40)2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37406614

RESUMO

Photocatalytic CO2reduction is considered to be an appealing way of alleviating environmental pollution and energy shortages simultaneously under mild condition. However, the activity is greatly limited by the poor separation of the photogenerated carriers. Ion doping is a feasible strategy to facilitate the charge transfer. In this work, Ni-doped Bi4O5I2photocatalyst is successfully fabricated using a one-pot hydrothermal method. A few doping levels appear in the energy band of Bi4O5I2after Ni doping, which are used as springboards for electrons transition, thus promoting photoexcited electrons and holes separation. As a consequence, a remarkably enhanced yield of CO and CH4(6.2 and 1.9µmol g-1h-1) is obtained over the optimized Bi4O5I2-Ni15, which is approximately 2.1 and 3.8 times superior to pure Bi4O5I2, respectively. This work may serve as a model for the subsequent research of Bi-based photocatalysts to implement high-performance CO2photoreduction.

7.
J Environ Sci (China) ; 127: 60-68, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36522089

RESUMO

With increasing concerns on the environment and human health, the degradation of glyphosate through the formation of less toxic intermediates is of great importance. Among the developed methods for the degradation of glyphosate, photodegradation is a clean and efficient strategy. In this work, we report a new photocatalyst by doping F ion on BiVO4 that can efficiently degrade glyphosate and reduce the toxic emissions of aminomethylphosphonic acid (AMPA) through the selective (P)-C-N cleavage in comparison of BiVO4 catalyst. The results demonstrate that the best suppression of AMPA formation was achieved by the catalyst of 0.3F@BiVO4 at pH = 9 (AMPA formation below 10%). In situ attenuated total reflectance Fourier transforms infrared (ATR-FTIR) spectroscopy indicates that the adsorption sites of glyphosate on BiVO4 and 0.3F@BiVO4 are altered due to the difference in electrostatic interactions. Such an absorption alteration leads to the preferential cleavage of the C-N bond on the N-C-P skeleton, thereby inhibiting the formation of toxic AMPA. These results improve our understanding of the photodegradation process of glyphosate catalyzed by BiVO4-based catalysts and pave a safe way for abiotic degradation of glyphosate.


Assuntos
Flúor , Glicina , Humanos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico , Fotólise , Glifosato
8.
J Environ Manage ; 321: 115982, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36104886

RESUMO

Hydrodynamic cavitation has been a promising method and technology in wastewater treatment, while the principles based on the design of cavitational reactors to optimize cavitation yield and performance remains lacking. Computational fluid dynamics (CFD), a supplementation of experimental optimization, has become an essential tool for this issue, owing to the merits of low investment and operating costs. Nevertheless, researchers with a non-engineering background or few CFD fundamentals used straightforward numerical strategies to treat cavitating flows, and this might result in many misinterpretations and consequently poor computations. This review paper presents the rationale behind hydrodynamic cavitation and application of cavitation modeling specific to the reactors in wastewater treatment. In particular, the mathematical models of multiphase flow simulation, including turbulence closures and cavitation models, are comprehensively described, whilst the advantages and shortcomings of each model are also identified and discussed. Examples and methods of the coupling of CFD technology, with experimental observations to investigate into the hydrodynamic behavior of cavitating devices that feature linear and swirling flows, are also critically summarized. Modeling issues, which remain unaddressed, i.e., the implementation strategies of numerical models, and the definition of cavitation numbers are identified and discussed. Finally, the advantages of CFD modeling are discussed and the future of CFD applications in this research area is also outlined. It is expected that the present paper would provide decision-making support for CFD beginners to efficiently perform CFD modeling and promote the advancement of cavitation simulation of reactors in the field of wastewater treatment.


Assuntos
Hidrodinâmica , Purificação da Água , Simulação por Computador , Modelos Teóricos , Tecnologia
9.
Angew Chem Int Ed Engl ; 61(19): e202200413, 2022 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-35166425

RESUMO

Synthesizing H2 O2 from water and air via a photocatalytic approach is ideal for efficient production of this chemical at small-scale. However, the poor activity and selectivity of the 2 e- water oxidation reaction (WOR) greatly restricts the efficiency of photocatalytic H2 O2 production. Herein we prepare a bipyridine-based covalent organic framework photocatalyst (denoted as COF-TfpBpy) for H2 O2 production from water and air. The solar-to-chemical conversion (SCC) efficiency at 298 K and 333 K is 0.57 % and 1.08 %, respectively, which are higher than the current reported highest value. The resulting H2 O2 solution is capable of degrading pollutants. A mechanistic study revealed that the excellent photocatalytic activity of COF-TfpBpy is due to the protonation of bipyridine monomer, which promotes the rate-determining reaction (2 e- WOR) and then enhances Yeager-type oxygen adsorption to accelerate 2 e- one-step oxygen reduction. This work demonstrates, for the first time, the COF-catalyzed photosynthesis of H2 O2 from water and air; and paves the way for wastewater treatment using photocatalytic H2 O2 solution.


Assuntos
Peróxido de Hidrogênio/síntese química , Estruturas Metalorgânicas , Oxigênio , Fotossíntese , Água
10.
Immunology ; 160(2): 209-219, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32149403

RESUMO

CD100 is an immune semaphorin constitutively expressed on T-cells. Matrix metalloproteinase (MMP) is an important mediator of membrane-bound CD100 (mCD100) cleavage to generate soluble CD100 (sCD100), which has immunoregulatory activity in immune cell responses. The aim of the study was to investigate the level and role of sCD100 and mCD100 in modulating CD8+ T-cell function in non-small cell lung cancer (NSCLC). sCD100 and MMP-14 levels in the serum and bronchoalveolar lavage fluid (BALF), and mCD100 expression on peripheral and lung-resident CD8+ T-cells were analysed in NSCLC patients. The ability to induce sCD100 and the effect of MMP-14 on mCD100 shedding for the regulation of non-cytolytic and cytolytic functions of CD8+ T-cells were also analysed in direct and indirect contact co-culture systems. NSCLC patients had lower serum sCD100 and higher mCD100 levels on CD8+ T-cells compared with healthy controls. BALF from the tumour site also had decreased sCD100 and increased mCD100 on CD8+ T-cells compared with the non-tumour site. Recombinant CD100 stimulation enhanced non-cytolytic and cytolytic functions of CD8+ T-cells from NSCLC patients, whereas blockade of CD100 receptor CD72 attenuated CD8+ T-cell activity. NSCLC patients had lower MMP-14 in the serum and in BALF from the tumour site. Recombinant MMP-14 mediated mCD100 shedding from CD8+ T-cell membrane, and led to promotion of CD8+ T-cell response in NSCLC patients. Overall, decreased MMP-14 resulted in insufficient CD100 shedding, leading to suppression of peripheral and lung-resident CD8+ T-cell activity in NSCLC.


Assuntos
Antígenos CD/metabolismo , Linfócitos T CD8-Positivos/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Neoplasias Pulmonares/imunologia , Metaloproteinase 14 da Matriz/metabolismo , Semaforinas/metabolismo , Adulto , Idoso , Antígenos CD/sangue , Líquido da Lavagem Broncoalveolar/química , Linfócitos T CD8-Positivos/metabolismo , Carcinoma Pulmonar de Células não Pequenas/sangue , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Técnicas de Cocultura , Feminino , Humanos , Pulmão/patologia , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/patologia , Ativação Linfocitária , Masculino , Metaloproteinase 14 da Matriz/sangue , Pessoa de Meia-Idade , Cultura Primária de Células , Proteínas Recombinantes/metabolismo , Semaforinas/sangue , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Evasão Tumoral , Microambiente Tumoral/imunologia
11.
Environ Sci Technol ; 54(6): 3691-3701, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32100998

RESUMO

The application of photocatalytic sterilization technology for the sterilization of water has been broadly studied in recent years. However, developing photocatalysts with high disinfection efficiency remains an urgent challenge. Tungsten trioxide with coexisting oxygen vacancies and carbon coating (WO3-x/C) has been successfully synthesized toward the photothermal inactivation of Escherichia coli. Oxygen vacancies and carbon coating bring WO3-x/C strong absorption in the infrared region and enhance the carrier separation efficiency. As a result, a higher sterilization rate is obtained compared to WO3. WO3-x/C can completely inactivate E. coli under infrared light within 40 min through photothermal synergy process. During the process of inactivating bacteria over WO3-x/C, E. coli is killed by the destruction of their cell membrane to decrease the activity of enzymes and release the cell contents, which can be ascribed to the efficient generation of reactive oxygen species (O2•- and •OH) and thermal effect. This work demonstrates a novel approach for engineering efficient and energy-saving catalysts for water sterilization.


Assuntos
Escherichia coli , Luz , Bactérias , Catálise , Desinfecção
12.
Cell Physiol Biochem ; 47(6): 2407-2419, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29991058

RESUMO

BACKGROUND/AIMS: Interleukin (IL)-35 has immunosuppressive functions in autoimmune diseases, infectious diseases, and certain cancers. However, few studies have focused on its immunoregulatory activity in non-small cell lung cancer (NSCLC). Thus, we investigated the role of IL-35 in the pathogenesis of this disease. METHODS: A total of 66 NSCLC patients and 21 healthy individuals were enrolled. IL-35 expression in peripheral blood and bronchoalveolar lavage fluid (BALF) was measured. The modulatory functions of IL-35 on purified CD4+ and CD8+ T cells from NSCLC patients were investigated in direct and indirect coculture systems with NSCLC cell lines. RESULTS: IL-35 expression was significantly increased in BALF from the tumor site, but not in the peripheral blood of NSCLC patients. IL-35 did not affect the bioactivity including proliferation, cytokine production, cell cycle, and cellular invasion of NSCLC cells. It suppressed responses from type 1 T helper (Th1) and Th17 cells but elevated the regulatory T cell response in cultured CD4+ T cells from NSCLC patients, and reduced cytokine-mediated CD4+ T cells cytotoxicity to NSCLC cells. Moreover, IL-35 also inhibited cytotoxic gene expression in CD8+ T cells from NSCLC, reducing their cytolytic and noncytolytic functions. CONCLUSION: The results of this study suggest that IL-35 contributes to the dysfunction/exhaustion of T cells and limited antitumor immune responses in NSCLC.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Regulação Neoplásica da Expressão Gênica/imunologia , Interleucinas/imunologia , Neoplasias Pulmonares/imunologia , Proteínas de Neoplasias/imunologia , Idoso , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade
13.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 37(3): 310-313, 2017 Mar.
Artigo em Zh | MEDLINE | ID: mdl-30650481

RESUMO

Objective To observe the distribution features of Gan depression qi stagnation syndrome (GDQSS) , and to analyze the correlation between GDQSS scores and thyroid stimulating hormone (TSH) level in adolescent polycystic ovary syndrome (PCOS) patients. Methods Disease location and disease nature were syndrome identified in PCOS outpatients confirmed at Department of Gynecology, Ningbo Municipal Hospital of TCM. Totally 110 patients in line with GDQSS were graded by GDQSS score from low to high. GDQSS score ranging 70 -100 belonged to grade I (mild) ; 101 -150 to grade II (moderate) ; >150 to grade III (severe). The correlation between the severity of GDQSS and TSH level was an- alyzed using Pearson and Partial correlation analyses. Results Levels of TSH, testosterone (T) , pro- lactin (PRL) were the lowest in grade I GDQSS patients, and they were the highest in grade lIl GDQSS patients (P <0. 01). Pearson correlation analysis showed that GDQSS score was positively correlated with TSH level (r =0. 676, P <0. 01). They were still positively correlated by using Partial correlation after controlling body mass index (BMI) , waist hip ratio (WHR) , homeostasis model of assessment-insulin resistance (HOMR-IR) factors (r =0. 663, P <0. 01). Conclusion Adolescent PCOS patients with obvi- ous GDQSS symptoms might be associated with increased TSH level.


Assuntos
Depressão , Resistência à Insulina , Síndrome do Ovário Policístico , Qi , Adolescente , Índice de Massa Corporal , Feminino , Hormônio Foliculoestimulante , Humanos , Insulina , Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/fisiopatologia , Síndrome do Ovário Policístico/psicologia , Tireotropina/sangue
15.
Phys Chem Chem Phys ; 17(36): 23489-95, 2015 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-26293350

RESUMO

In this paper, BiOI@(BiO)2CO3 facet coupling heterostructures were synthesized via exfoliation and ion exchange, and characterized by X-ray diffraction (XRD) patterns, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectra (DRS), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) spectra and valence-band XPS spectra. With the reaction time increasing, more BiOI can be transformed to (BiO)2CO3, and BiOI@(BiO)2CO3 facet coupling heterostructures were obtained. The photocatalytic results showed that BiOI@(BiO)2CO3 displays much higher photocatalytic activity than BiOI and (BiO)2CO3 under visible-light. The photocatalytic mechanism study revealed that BiOI@(BiO)2CO3 has strong adsorption for RhB molecules due to the ultrathin nanosheets and higher BET, and displays better separation efficiency of photoinduced charge carriers and higher photocurrent due to the {001}/{001} facet coupling.

16.
Phys Chem Chem Phys ; 16(29): 15675-80, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24960436

RESUMO

We firstly demonstrate the opposite photocatalytic activity orders of low-index facets of anatase TiO2 in the liquid phase for rhodamine B (RhB) photocatalytic degradation and in the gaseous phase for the photoreduction of CO2 to CH4. The photocatalytic activity order in the liquid phase for RhB photocatalytic degradation is revealed as {001} > {101} > {010}, whereas the photocatalytic activity order {010} > {101} > {001} is found in the gaseous phase for the photoreduction of CO2 to CH4. The atomic arrangement of the different facets, UV-vis diffuse reflectance spectra, photoluminescence spectra and attenuated total reflectance Fourier transform infrared spectroscopy analysis show that the photoactivity order in the gas phase for the photoreduction of CO2 to CH4 mainly depends on the CO2 molecule adsorption properties on the different exposed facets, and the separation efficiency of the photo-generated carriers determines the photoactivity order for the dye degradation reaction in the liquid phase. These findings also provide a new direction to design efficient photocatalysts and the tuning of their photoreactivity for environmental and energy applications.

17.
ACS Appl Mater Interfaces ; 16(1): 633-642, 2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38150331

RESUMO

It is highly desirable to fabricate transition bimetallic alloy-embedded porous nanocarbons with a unique nanoarchitecture for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in rechargeable zinc-air batteries. In this work, we introduce a template-assisted in situ alloying synthesis of FeNi alloy nanoparticle-decorated coral-like nanocarbons (FeNi-CNCs) as efficient OER/ORR dual-functional electrocatalysts. The present materials are produced through polycondensation of a covalent triazine framework (CTF), the coordination of Ni and Fe ions, and sequential pyrolytic treatment. Through the pyrolysis process, the nanolamellar FeNi-CTF precursors can be facilely converted into FeNi alloy nanoparticle-decorated nanocarbons. These nanocarbons possess a distinctive three-dimensional (3D) coral-like nanostructure, which is favorable for the transport of oxygen and the diffusion of electrolyte. As a result, FeNi-CNC-800 with the highest efficiency exhibited remarkable electrocatalytic performance and great durability. Additionally, it also can be assembled into rechargeable zinc-air batteries that can be assembled in both liquid and solid forms, offering a superior peak power density, large specific capacity, and outstanding reusability during charging/discharging cycles (e.g., 5160 charging-and-discharging cycles at 10 mA cm-2 for the liquid forms). These traits make it a highly promising option in the burgeoning field of wearable energy conversion.

18.
ACS Nano ; 18(8): 6579-6590, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38353995

RESUMO

Excitonic effects significantly influence the selective generation of reactive oxygen species and photothermal conversion efficiency in photocatalytic reactions; however, the intrinsic factors governing excitonic effects remain elusive. Herein, a series of single-atom catalysts with well-defined M1-N3C1 (M = Mn, Fe, Co, and Ni) active sites are designed and synthesized to investigate the structure-activity relationship between photocatalytic materials and excitonic effects. Comprehensive characterization and theoretical calculations unveil that excitonic effects are positively correlated with the number of valence electrons in single metal atoms. The single Mn atom with 5.93 valence electrons exhibits the weakest excitonic effects, which dominate superoxide radical (O2•-) generation through charge transfer and enhance photothermal conversion efficiency. Conversely, the single Ni atom with 9.27 valence electrons exhibits the strongest excitonic effects, dominating singlet oxygen (1O2) generation via energy transfer while suppressing photothermal conversion efficiency. Based on the valence electron number dependent excitonic effects, a reaction environment with hyperthermia and abundant cytotoxic O2•- is designed, achieving efficient and stable water disinfection. This work reveals single metal atom dependent excitonic effects and presents an atomic-level methodology for catalytic application targeted reaction environment tailoring.

19.
Adv Mater ; 36(18): e2312868, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38241728

RESUMO

The intelligent construction of non-noble metal materials that exhibit reversible oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with bifunctional electrocatalytic performance is greatly coveted in the realm of zinc-air batteries (ZABs). Herein, a crafted structure-amorphous MnO2 lamellae encapsulated covalent triazine polymer-derived N, S, P co-doped carbon sphere (A-MnO2/NSPC) is designed using a self-doped pyrolysis coupled with an in situ encapsulation strategy. The customized A-MnO2/NSPC-2 demonstrates a superior bifunctional electrocatalytic performance, confirmed by a small ΔE index of 0.64 V for ORR/OER. Experimental investigations, along with density functional theory calculations validate that predesigned amorphous MnO2 surface defects and abundant heteroatom catalytic active sites collectively enhance the oxygen electrocatalytic performance. Impressively, the A-MnO2/NSPC-based rechargeable liquid ZABs show a large open-circuit potential of 1.54 V, an ultrahigh peak power density of 181 mW cm-2, an enormous capacity of 816 mAh g-1, and a remarkable stability for more than 1720 discharging/charging cycles. Additionally, the assembled flexible all-solid-state ZABs also demonstrate outstanding cycle stability, surpassing 140 discharging/charging cycles. Therefore, this highly operable synthetic strategy offers substantial understanding in the development of magnificent bifunctional electrocatalysts for various sustainable energy conversions and beyond.

20.
Chem Commun (Camb) ; 59(90): 13478-13481, 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37880980

RESUMO

A strategy involving organic photocatalytic conversion using hydrothermal synthesis of high-entropy oxide (HEO) (CoCuZnMnNa)Ox nanoparticles was developed. Under mild conditions, HEO nanoparticles were driven by visible light to achieve ideal yields and selectivity in sulfide oxidative coupling reactions and benzimidazole cyclization reactions, with a wide substrate range. This study is expected to contribute to the use of high-entropy oxides in organic photocatalysis.

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