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1.
J Colloid Interface Sci ; 678(Pt B): 885-901, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39270389

RESUMO

Designing efficient sulfide photocatalysts for the simultaneous split water into H2 and O2 continue to be an arduous challenge. Herein, a Zn-vacancy mediated S-scheme MnCdS/ZnS-VZn heterojunction derived from MnCdS/MOF-5 via in-situ vulcanization of MOF-5 in a new-fashioned sacrificial reagent of Na2S/NaH2PO2 was fabricated. The presence of Zn vacancy (VZn) was certified by TEM, XPS, EPR and PL results, which result in a new defect level in the band structure of ZnS. The S-scheme charge transfer path was established between MnCdS and ZnS-VZn by VZn vacancies, and the photocorrosion is depressed efficiently and a dramatic rise occurs on photocatalytic performance. The strong electron coupling effect of S-scheme heterojunction mechanism was confirmed via in-situ XPS, SPV, work function, and radicals test by EPR. The band gap and density of state about ZnS-VZn and MnCdS are also calculated by the DFT. In HER semi-reaction, the strongest photocatalytic hydrogen generation rate of 20 % MnCdS/ZnS-VZn is 394.4 µmol/h with a splendid apparent quantum efficiency of 16.43 % at 420 nm, and the turnover number (TON) is 98.6. The hydrogen production rate of 20 % MnCdS/ZnS-VZn is drastically advanced by 123.25 times in contrast to the unadorned ZnS-VZn. And superior photostability is also obtained. Prominently, the high-efficiency and steady photocatalytic overall water splitting rates of 5.7µmol/h (H2) and 3.0µmol/h (O2) were achieved over 20 % MnCdS/ZnS-VZn with 1 %wt Pt and 5 %wt Co3O4 nanorod as cocatalysts, and the photocatalytic stability was excellent. This research supplies neoteric insights for designing of highly efficient VZn-mediated S-scheme sulfide photocatalysts to achieve pure water overall splitting with superior photocatalytic activity.

2.
Nanoscale ; 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39225062

RESUMO

Utilizing the design of heterojunction structures formed between photocatalysts to enhance photoelectrochemical performance represents an effective strategy for improving the efficiency of photocatalytic hydrogen production. In this work, a straightforward one-step solvothermal method was employed to embed NENU-5 nano-octahedra within ZnIn2S4 nanoflowers, forming ZnIn2S4@NENU-5 heterostructures. Hydrogen production tests conducted over 5 h revealed a hydrogen evolution activity of 5282.14 µmol g-1 h-1 in triethanolamine (TEOA) solution at pH = 9, which is 4.9 times and 264 times higher than that of pure ZnIn2S4 and NENU-5, respectively. The significant enhancement in the photocatalytic performance indicates that the constructed Z-scheme heterojunction increases the active sites on the catalyst surface and plays a crucial role in photocarrier transfer. Furthermore, the formation of the Z-scheme heterojunction is confirmed through Mott-Schottky (M-S) analysis, ultraviolet photoelectron spectroscopy (UPS), and valence band X-ray photoelectron spectroscopy (VB-XPS). The effective charge transfer at the ZnIn2S4@NENU-5 heterojunction interface is validated based on X-ray photoelectron spectroscopy (XPS), photoluminescence (PL) analysis, and density functional theory (DFT) calculations. In summary, this work offers an effective approach to designing novel heterojunction photocatalysts by combining MOF materials with bimetallic sulfides, thereby promoting the efficiency of photocatalytic hydrogen production.

3.
Nanoscale ; 16(36): 17009-17023, 2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39189038

RESUMO

Rational design and synthesis of a unique heterojunction photocatalyst structure is an important strategy to enhance its performance and structural stability. Herein, Co9S8/MnCdS/Co3O4 photocatalysts with double S-scheme heterojunctions were successfully prepared by coupling Co9S8 and Co3O4 sheet structures with n-type MnCdS nanoparticles through a simple solvothermal and mechanical mixing method. The construction of the dual S-scheme heterostructure offers the possibility to expand the light absorption range, extend the carrier lifetime and maximise the redox capacity. In addition, the mechanism of charge transfer and the reason for the improvement of photocatalytic activity were explored through photoelectrochemical characterization. The lamellar structures of Co9S8 and Co3O4 not only provide excellent dispersion and slow down the agglomeration of MnCdS nanoparticles, but also promote charge transfer, which improves the photocatalytic hydrogen production effect. Under simulated solar irradiation, the evolution rate of H2 after 5 h was as high as 46.44 µmol, which was 3.49 and 1.49 times higher than those of pristine MnCdS and MnCdS/Co3O4, respectively. Meanwhile, it has good stability under 20 h irradiation. This work demonstrates a novel idea for the rational design of double S-scheme photocatalysts with efficient space separation.

4.
J Colloid Interface Sci ; 677(Pt B): 205-220, 2024 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-39142161

RESUMO

The research in the field of photocatalysis has progressed, with the development of heterojunctions being recognized as an effective method to improve carrier separation efficiency in light-induced processes. In this particular study, CuCo2S4 particles were attached to a new cubic CdS surface to create an S-scheme heterojunction, thus successfully addressing this issue. Specifically, owing to the higher conduction band and Fermi level of CuCo2S4 compared to CdS, they serve as the foundation and driving force for the formation of an S-scheme heterojunction. Through in-situ X-ray photoelectron spectroscopy and electron paramagnetic resonance analysis, the direction of charge transfer in the composite photocatalyst under light exposure was determined, confirming the charge transfer mechanism of the S-scheme heterojunction. By effectively constructing the S-scheme heterojunction, the d-band center of the composite photocatalyst was adjusted, reducing the energy needed for electron filling in the anti-bonding energy band, promoting the transfer of photogenerated carriers, and ultimately enhancing the photocatalytic hydrogen production. performance. After optimization, the hydrogen evolution activity of the composite photocatalyst CdS-C/CuCo2S4-3 reached 5818.9 µmol g-1h-1, which is 2.6 times higher than that of cubic CdS (2272.3 µmol g-1h-1) and 327.4 times higher than that of CuCo2S4 (17.8 µmol g-1h-1), showcasing exceptional photocatalytic activity. Electron paramagnetic resonance and in situ X-ray photoelectron spectroscopy have established a theoretical basis for designing and constructing S-scheme heterojunctions, offering a viable method for adjusting the D-band center to enhance the performance of photocatalytic hydrogen evolution.

5.
J Colloid Interface Sci ; 677(Pt A): 1016-1028, 2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39128285

RESUMO

The efficiency of photocatalytic hydrogen evolution can be significantly enhanced while maintaining cost-effectiveness through the synergistic effect of defect surface engineering and multi-component heterojunctions. The structure and properties of NiCo2O4 nanorods were modified by inducing oxygen vacancies at different temperatures in this study, resulting in improved optical properties and electron adsorption capacity. The presence of oxygen vacancies leads to a reduction in the band gap of NiCo2O4, thereby enhancing electron transport efficiency through band gap engineering. Simultaneously, surface properties undergo changes, and vacancy defects serve as electron trapping centers, facilitating an increased participation of electrons in the hydrogen evolution reaction process. The dodecahedron KMP with a cavity structure is additionally introduced to form an S-scheme heterojunction with NiCo2O4. This establishes a novel mechanism for electron transport, which effectively enhances the separation of electron-hole pairs and improves the redox capacity of the photocatalytic system. The adsorption of intermediates in the hydrogen production process is enhanced through synergistic regulation of d-band centers via surface defect engineering and S-scheme heterojunction. Additionally, this approach improves the separation efficiency of electron-hole pairs and accelerates electron transfer dynamics, significantly enhancing hydrogen production efficiency.

6.
Nanoscale ; 16(30): 14498-14509, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-39028270

RESUMO

Metal coordination polymers are organometallic frameworks in which a metal and an organic ligand are linked via a dative bond. The material in question exhibits ultra-high porosity, large specific surface area, and abundant active sites, which can be customised in terms of morphology, size, and electronic structure through rational design. Graphdiyne, a novel two-dimensional carbon allotrope, boasts structural stability and enhanced electrical conductivity due to its hybridization of sp2 and sp carbons. A metal-organic framework of Co (MOF-67) was synthesized via hydrothermal synthesis. The introduction of polyvinyl pyrrolidone (PVP) served as a structural regulator and surfactant to obtain a more active metal coordination polymer (Co-MCPS). PVP, in its dual role, significantly amplified the catalytic performance of metal coordinate polymers, as demonstrated in a number of experiments. The incorporation of GDY onto the surfaces of MOF-67 and Co-MCPS induced an electron-rich isolation layer, which could effectively sequester oxidation sites, thereby enhancing the rate of charge carrier separation and hydrogen precipitation evolution efficiency.

7.
ACS Appl Mater Interfaces ; 16(28): 36333-36342, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38950183

RESUMO

The photocatalytic conversion of solar energy to hydrogen is a promising pathway toward clean fuel production, yet it requires advancement to meet industrial-scale demands. This study demonstrates that the interface engineering of heterojunctions is a viable strategy to enhance the photocatalytic performance of CuInS2/Mo2S3. Specifically, CuInS2 nanoparticles are incorporated into Mo2S3 nanospheres via a wet impregnation technique to form an S-scheme heterojunction. This configuration facilitates directional electron transfer, optimizing electron utilization and fostering efficient photocatalytic processes. The presence of an S-scheme heterojunction in CuInS2/Mo2S3 is corroborated by in situ irradiation X-ray photoelectron spectroscopy and density functional theory analyses, which confirm the directional movement of electrons at the interface of heterojunction. Comprehensive characterization of the heterojunction photocatalyst, including phase, structural, and photoelectric property assessments, reveals a significant specific surface area and light absorption capability. These attributes augment the number of active sites available in CuInS2/Mo2S3 for proton reduction reactions. This study offers a pragmatic approach for designing metal sulfide-based photocatalysts via strategic interface engineering, potentially advancing the field toward sustainable hydrogen production.

8.
Angew Chem Int Ed Engl ; : e202408275, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-39073840

RESUMO

In the case of CO2 thermal-catalytic hydrogenation, highly selective olefin generation and subsequent olefin secondary reactions to fuel hydrocarbons in an ultra-short residence time is a huge challenge, especially under industrially feasible conditions. Here, we report a pioneering synthetic process that achieves selective production of high-volume commercial gasoline with the assistance of fast response mechanism. In situ experiments and DFT calculations demonstrate that the designed NaFeGaZr presents exceptional carbiding prowess, and swiftly forms carbides even at extremely brief gas residence times, facilitating olefin production. The created successive hollow zeolite HZSM-5 further reinforces aromatization of olefin diffused from NaFeGaZr via optimized mass transfer in the hollow channel of zeolite. Benefiting from its rapid response mechanism within the multifunctional catalytic system, this catalyst effectively prevents the excessive hydrogenation of intermediates and controls the swift conversion of intermediates into aromatics, even in high-throughput settings. This enables a rapid one-step synthesis of high-quality gasoline-range hydrocarbons without any post-treatment, with high commercial product compatibility and space-time yield up to 0.9 kggasoline·kgcat-1·h-1. These findings from the current work can provide a shed for the preparation of efficient catalysts and in-depth understanding of C1 catalysis in industrial level.

9.
Phys Chem Chem Phys ; 26(27): 18788-18798, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38938074

RESUMO

The charge density and charge transfer resistance of the assisting catalyst have a significant impact on the hydrogen evolution performance of bimetallic sulfides. However, existing mechanistic discussions often overlook the charge density between the two catalysts and whether the assisting catalyst produces enough photo-generated electrons. Here, we propose a simple method for the synthesis of 2-acetylene-(copper metal-organic frameworks) (ACu-MOFs) to improve the hydrogen evolution performance of bimetallic sulfides. Compared to copper metal-organic frameworks (Cu-MOFs), these ACu-MOFs have higher charge density and lower charge transfer resistance. More importantly, the introduction of alkyne-based Cu-MOFs further promotes the hydrogen evolution performance of bimetallic sulfides under 5 W LED light, and XPS is used to determine the difference in charge density between ACu-MOFs and Cu-MOFs and the improvement in contact electron transfer after bimetallic sulfide modification. This work mainly discusses the charge density, charge transfer resistance, and the number of photo-excited electrons generated, and provides a reasonable explanation.

10.
Curr Med Chem ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38860909

RESUMO

As members of the protein tyrosine kinase family, the Epidermal Growth Factor Receptor (EGFR) and Human Epidermal Growth Factor Receptor 2 (HER2) play essential roles in cellular signal transduction pathways. Overexpression or abnormal activation of EGFR and HER2 can lead to the development of various solid tumors. Therefore, they have been confirmed as biological targets for the development of anticancer drugs. Due to the fact that many cancers are highly susceptible to developing resistance to single-target EGFR inhibitors in clinical practice, dual inhibitors that target both EGFR and HER2 have been developed to increase efficacy, reduce drug resistance and interactions, and improve patient compliance. Currently, a variety of EGFR/HER2 dual inhibitors have been developed, with several drugs already approved for marketing or in clinical trials. In this review, we summarize recent advancements in small-molecule EGFR/HER2 dual inhibitors by focusing on structure-activity relationships and share novel insights into developing anticancer agents.

11.
J Colloid Interface Sci ; 672: 700-714, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38870761

RESUMO

Precisely crafting heterojunctions for efficient charge separation is a major obstacle in the realm of photocatalytic hydrogen evolution. A 0D/2D heterojunction was successfully fabricated by anchoring Ag2S quantum dots (Ag2S QDs) onto graphdiyne (GDY) nanosheets (Ag2S QDs/GDY) using a straightforward physical mixing technique. This unique structure allows for excellent contact between GDY and Ag2S QDs, thereby enhancing the rate of charge transfer. The light absorption capabilities of Ag2S QDs/GDY extend up to 1200 nm, enabling strong absorption of light, including infrared. Through DFT calculations and in-situ XPS analysis, it was demonstrated that incorporating Ag2S QDs onto GDY effectively modulates the electronic structure, promotes an internal electric field, and facilitates directional electron transfer. This directed electron transfer enhances the utilization of electrons by GDY and Ag2S QDs, with the added benefit of Ag2S QDs serving as electron reservoirs for efficient photocatalytic hydrogen evolution. A 7 %Ag2S QDs/GDY composite exhibited impressive efficiency and stable performance in photocatalytic hydrogen evolution (2418 µmol g-1 h-1), which is much higher than that of GDY and Ag2S QDs. This study conclusively demonstrates that the 0D/2D heterojunction formed by GDY and Ag2S QDs can establish high-quality contact and efficient charge transfer, ultimately enhancing photocatalytic performance.

12.
ACS Omega ; 9(19): 21270-21275, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38764683

RESUMO

Using low viscosity engine oil is one of the most economical and easily achievable ways to improve fuel economy. Base oil is a main component in low viscosity engine oils, and therefore, the separation and identification of its are of great significance for oil product developers to prepare high-performance lubricants. However, the extraction methods reported for base oils mainly adopt membrane dialysis, which not only fails to completely separate the base oil but also wastes a large amount of solvent. The reason for this result is that the concentration of substances inside and outside the membrane cannot always be in an imbalanced state of permeation resulting from manual operation. Additionally, most studies primarily focus on the characterization of base oil components, while there are few reports on grade identification. For the above reasons, an economically effective separation technique of base oil from low viscosity gasoline engine oil SN 0W-16 is successfully established by combining improved Soxhlet extraction and a column chromatography separation method. By applying this method, the yield of extracting base oil generally exceeds 96%, and the solvent can also save more than 3 times. Besides, an exclusion method is built through several simple characterization steps including viscosity index (VI), FT-IR, size-exclusion chromatography (SEC), and hydrocarbon composition, which can quickly identify the American Petroleum Institute (API) grade and brand of the base oils.

13.
Discov Oncol ; 15(1): 56, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38430429

RESUMO

BACKGROUND: T cell exhaustion (TEX) signifies a condition of T cell disorder which implicate the therapeutic benefits and prognostic significance in patients with cancer. However, its role in the Head and Neck Squamous Carcinoma (HNSCC) remains incompletely understood. METHODS: The detailed data of HNSCC samples were obtained from The Cancer Genome Atlas (TCGA) database and two Gene Expression Omnibus (GEO) datasets. We computed the expression scores of four TEX-related pathways and detected gene modules closely linked to these pathways, indicating prognostic significance. Following this, regression analyses were performed to select eight genes for the development of a predictive signature. The predictive capacity of this signature was evaluated. Additionally, we examined the relationships between TEX-related signature risk scores and the effectiveness of immunotherapy as well as drug sensitivity. RESULTS: A novel prognostic model, comprising eight TEX-related genes, was established for patients with HNSCC. The prognostic value was further confirmed using additional GEO datasets: GSE65858 and GSE27020. This signature enables the stratification of patients into high- and low- risk groups, each showing distinct survival outcomes and responsiveness to immunotherapy. The low-risk group demonstrated improved prognosis and enhanced efficacy of immunotherapy. In addition, AZD6482, TAF1, Ribociclib, LGK974, PF4708671 and other drugs showed increased sensitivity in the high-risk group based on drug sensitivity values, offering tailored therapeutic recommendations for individuals with various risks profiles. CONCLUSION: In conclusion, we developed a novel T cell exhaustion-associated signature, which holds considerable predictive value for both the prognosis of patients with HNSCC and the effectiveness of tumor immunotherapy.

14.
Small ; 20(31): e2311441, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38446057

RESUMO

Tailoring advanced anisotropy-driven efficient separation and migration of photogenerated carriers is a pivotal stride toward enhancing photocatalytic activity. Here, CdS-MoS2 binary photocatalysts are tailored into a dumbbell shape by leveraging the rod-shaped morphology of CdS and employing an in situ tip-induction strategy. To further enhance the photocatalytic activity, an in situ photo-deposition strategy is incorporated to cultivate MnOx particles on the dumbbell-shaped CdS-MoS2. The in situ deposition of MnOx effectively isolated the oxidatively active sites on the CdS surface, emphasizing the reductively active crystalline face of CdS, specifically the (002) face. Benefiting from its robust activity as a reduction active site, MoS2 adeptly captures photogenerated electrons, facilitating the reduction of H+ to produce hydrogen. The anisotropically driven separation of CdS photogenerated carriers markedly mitigates the Coulomb force or binding force of the photogenerated electrons, thus promoting a smoother migration toward the active site for photocatalytic hydrogen evolution. The hydrogen evolution rate of 35MnOx-CdS-MoS2-3 surpasses that of CdS by nearly an order of magnitude, achieving a quantum efficiency of 22.30% at 450 nm. Under simulated solar irradiation, it attains a rate of 42.86 mmol g-1 h-1. This work imparts valuable insights for the design of dual co-catalysts, anisotropy-driven spatial vectorial charge separation and migration, and the analysis of migration pathways of photogenerated carriers.

15.
Langmuir ; 40(10): 5011-5025, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38410908

RESUMO

Graphdiyne (GDY) is a new two-dimensional carbon network material composed of sp2 hybrid carbon and sp hybrid carbon conjugation. It has unique physical and chemical properties, such as high porosity, good electrical conductivity, high carrier mobility, adjustable band gap, and so on. The preparation of GDY and GDY derivatives by adjusting physical and chemical methods and changing monomers has become the key material in the fields of photocatalysis, energy storage, life science, and so on. In this paper, new methods for controllable growth of GDY are reviewed, including liquid phase chemical classical total synthesis, chemical vapor deposition, the interface method, the explosion method, and the mechanically driven ball milling method. FT-IR, Raman, NMR, and XAS are the main means to characterize the structure of GDY. Finally, the representative application of GDY in the field of photocatalytic hydrogen evolution is summarized, and its future development has been explored.

16.
Nanoscale ; 16(5): 2361-2372, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38198207

RESUMO

An integral approach towards augmenting the performance of photocatalytic hydrogen production lies in the induction of charge transfer mediators within the material matrix itself, thereby facilitating swift and efficient charge transfer processes. Here, CoTiO3 is induced to grow its electronic attraction center, CoP3, through a high-temperature phosphatization strategy. CoP3 acts as the active reduction site for the hydrogen evolution reaction and enhances the photocatalytic performance of the pristine catalyst. Compared with pure CoTiO3, the PCTO7 hybrid catalyst with the electronic attraction center CoP3 exhibits a superior photocatalytic performance and good stability. Experimental results show that the hydrogen evolution performance of the PCTO7 hybrid catalyst reaches 56.52 µmol, which is 78 times higher than that of the single catalyst CoTiO3 (0.72 µmol). These results demonstrate that the hybrid catalyst with the self-induced electronic attraction center has a higher light absorption capacity, faster charge carrier dynamics and improved photogenerated charge carrier separation and transfer than pure CoTiO3, resulting in excellent redox capability. DFT calculations provide evidence supporting the topological metal properties of CoP3 as the electron sink center. This study provides a feasible approach for enhancing the photocatalytic performance of a pristine catalyst employing a high-temperature phosphatization-induced electron sink center.

17.
Genet Test Mol Biomarkers ; 27(12): 393-405, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38156905

RESUMO

Background: There is increasing evidence that abnormal expression of microRNAs is involved in the occurrence and progression of tumors. In previous experiments, we found that the content of hsa-miR-1301-3p in tumor tissues of patients with nonsmall cell lung cancer (NSCLC) showed an obvious upward trend compared with that in normal tissues. We performed a detailed study on the impact and underlying mechanism of hsa-miR-1301-3p in NSCLC cells. Methods: The impact of hsa-miR-1301-3p on NSCLC cell proliferation, apoptosis, migration, and invasion was examined using colony formation, flow cytometry, modified Boyden chamber, and wound healing assays. Different doses of radiation were applied to NSCLC cells to investigate their sensitivity to radiotherapy. The potential target gene of hsa-miR-1301-3p was determined by dual-luciferase reporter assay and immunoblotting. Result: hsa-miR-1301-3p was upregulated in NSCLC tissues and cells. hsa-miR-1301-3p effectively promoted the rapid proliferation, migration, and invasion of NSCLC cells, while inhibiting apoptosis. It also induced radioresistance in NSCLC cells. hsa-miR-1301-3p targeted the homeodomain-only protein homeobox (HOPX) mRNA 3' untranslated region and inhibited its transcription in NSCLC cells. Exogenous HOPX overexpression antagonized the mechanism by which hsa-miR-1301-3p regulates NSCLC cell proliferation, metastasis, and apoptosis. Conclusions: hsa-miR-1301-3p plays an oncogenic role in the occurrence and development of NSCLC. By targeting HOPX, hsa-miR-1301-3p can not only promote the proliferation and metastasis of NSCLC cells, but also alleviate apoptosis and reduce radiosensitivity.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , MicroRNAs , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Genes Homeobox , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Tolerância a Radiação/genética
18.
Nanoscale ; 15(39): 16131-16143, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37754749

RESUMO

Dynamics and morphology play a crucial role in the field of photocatalytic hydrogen production. Regulating the transfer of photogenerated charges is an effective way to improve the catalytic activity. In this paper, 1T-WS2 is introduced into a p-n heterostructure, ZnCdS/NiV-LDH, as a metalloid electron pump to transfer photogenerated electrons from semiconductors with larger work functions to metalloid materials with smaller work functions, effectively to attract photogenerated electrons, and promote charge rearrangement at the p-n heterostructure interface, so as to achieve the best utilization efficiency of photogenerated charges. Second, adjusting the morphology to increase the light absorption area of the catalyst is also a way to improve the photocatalytic activity. Two different nanosheet structures dispersed heavily stacked ZnCdS, increasing the light absorption area of the system. The optimal catalyst ratio achieves a hydrogen evolution rate of 22.37 mmol g-1 h-1, achieving 7.98% AQE and 2.12% STH conversion efficiency at 450 nm. The potential mechanism was demonstrated through in situ XPS. This study provides new insights into adding "electron pumps" to heterostructures to enhance photocatalytic activity.

19.
Dalton Trans ; 52(25): 8716-8727, 2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37310365

RESUMO

Among carbon allotropes, 2D graphdiyne (GDY) possesses the merits of good ductility, strong conductivity and an adjustable energy band structure. In this study, a GDY/ZnCo-ZIF S-scheme heterojunction photocatalyst has been successfully prepared by a low-temperature mixing method. Using eosin as a photosensitizer and triethanolamine as a solvent, the hydrogen production of the GDY/ZnCo-ZIF-0.9 composite reaches 171.79 µmol, which is 6.67 and 13.5 times that of the GDY and ZnCo-ZIF materials, respectively. The apparent quantum efficiency of the GDY/ZnCo-ZIF-0.9 composite at 470 nm is 2.8%. The improved photocatalytic efficiency may be attributed to the creation of an S-scheme heterojunction structure that enables efficient separation of space charges. In addition, the EY-sensitized GDY/ZnCo-ZIF catalyst endows the GDY with a special structure to provide an abundance of electrons for the ZnCo-ZIF material, thus facilitating the photocatalytic reduction reaction to produce hydrogen. A novel perspective is presented in this study regarding the construction of an S-scheme heterojunction based on graphdiyne for efficient photocatalytic hydrogen generation.

20.
Langmuir ; 39(28): 9816-9830, 2023 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-37389883

RESUMO

As a new two-dimensional (2D) carbon hybrid material, graphdiyne has attracted much attention due to its good conductivity, adjustable electronic structure, and special electron transfer enhancement properties. In this work, graphdiyne/CuO and NiMoO4/GDY/CuO composite catalysts were prepared by cross coupling method and high temperature annealing method. The CuI introduced by clever design not only acts as a catalytic coupling but also as a precursor of CuO. The CuO produced by the postprocessing improves the inefficient charge separation of graphdiyne and provides a good acceptor for the consumption of unwanted holes. The good conductivity and strong reduction ability of graphdiyne play key roles in the performance improvement of the composite catalyst. Under the dual evidence of XPS and in situ XPS, the charge transfer mode of double S-scheme heterojunction with graphdiyne as the active site of hydrogen evolution is constructed reasonably, which not only gives full play to the performance advantages of graphdiyne but also effectively improves the separation efficiency of photogenerated carriers. In this study, a clean and efficient multicomponent system was constructed by graphdiyne, which opened up a broad application prospect in the field of photocatalytic hydrogen production.

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