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1.
Small ; 20(22): e2309256, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38133479

RESUMO

Although 2D π-d conjugated metal-organic frameworks (MOFs) exhibit high in-plane conductivity, the closely stacked layers result in low specific surface area and difficulty in mass transfer and diffusion. Hence, a conductive 3D MOF Fe3(HITP)2/bpm@Co (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) is reported through inserting bpm (4,4'-bipyrimidine) ligands and Co2+ into the interlayers of 2D MOF Fe3(HITP)2. Compared to 2D Fe3(HITP)2 (37.23 m2 g-1), 3D Fe3(HITP)2/bpm@Co displays a huge improvement in the specific surface area (373.82 m2 g-1). Furthermore, the combined experimental and density functional theory (DFT) theoretical calculations demonstrate the metallic behavior of Fe3(HITP)2/bpm@Co, which will benefit to the electrocatalytic activity of it. Impressively, Fe3(HITP)2/bpm@Co exhibits prominent and stable oxygen evolution reaction (OER) performance (an overpotential of 299 mV vs RHE at a current density of 10 mA cm-2 and a Tafel slope of 37.14 mV dec-1), which is superior to 2D Fe3(HITP)2 and comparable to commercial IrO2. DFT theoretical calculation reveals that the combined action of the Fe and Co sites in Fe3(HITP)2/bpm@Co is responsible for the enhanced electrocatalytic activity. This work provides an alternative approach to develop conductive 3D MOFs as efficient electrocatalysts.

2.
Nano Lett ; 23(4): 1244-1251, 2023 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-36757119

RESUMO

Oxygen vacancies (OVs) on specific sites/facets can strengthen the interaction between reactants and oxide surfaces, facilitating interfacial charge transfer. However, precise monitoring of the spatial distribution of OVs remains a grand challenge. We report here that a single-particle spectroscopy technique addresses this challenge by establishing a positive correlation relationship between defects and bound exciton luminescence across different facets. Taking monoclinic BiVO4 as an example, on the basis of theoretical guidance, by in situ tracking the PL lifetimes and PL spectra of different facets on single particles before and after hydrogen treatment, we provide evidence that the PL emission originates from the OV state and determine that OVs is more inclined to be generated at the {010} facets. This anisotropic defect engineering significantly prolongs the lifetime of carriers and accelerates the activation of molecular oxygen. These findings not only verify preference rules of OVs in metal oxides but also provide a time-space-resolved monitoring method.

3.
Angew Chem Int Ed Engl ; 63(15): e202400965, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38363034

RESUMO

Recently, amorphous materials have gained great attention as an emerging kind of functional material, and their characteristics such as isotropy, absence of grain boundaries, and abundant defects are very likely to outrun the disadvantages of crystalline counterparts, such as low conductivity, and ultimately lead to improved charge transfer efficiency. Herein, we investigated the effect of amorphization on the charge transfer process and photocatalytic performance with a phosphonate-based metal-organic framework (FePPA) as the research object. Comprehensive experimental results suggest that compared to crystalline FePPA, amorphous FePPA has more distorted metal nodes, which affects the electron distribution and consequently improves the photogenerated charge separation efficiency. Meanwhile, the distorted metal nodes in amorphous FePPA also greatly promote the adsorption and activation of O2. Hence, amorphous FePPA exhibits a better performance of photocatalytic C(sp3)-H bond activation for selective oxidation of toluene to benzaldehyde. This work illustrates the advantages of amorphous MOFs in the charge transfer process, which is conducive to the further development of high performance MOFs-based photocatalysts.

4.
Angew Chem Int Ed Engl ; 63(14): e202318874, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38361162

RESUMO

The acidic electrochemical CO2 reduction reaction (CO2RR) for direct formic acid (HCOOH) production holds promise in meeting the carbon-neutral target, yet its performance is hindered by the competing hydrogen evolution reaction (HER). Understanding the adsorption strength of the key intermediates in acidic electrolyte is indispensable to favor CO2RR over HER. In this work, high-density Sn single atom catalysts (SACs) were prepared and used as catalyst, to reveal the pH-dependent adsorption strength and coverage of *CO2 - intermediatethat enables enhanced acidic CO2RR towards direct HCOOH production. At pH=3, Sn SACs could deliver a high Faradaic efficiency (90.8 %) of HCOOH formation and a corresponding partial current density up to -178.5 mA cm-2. The detailed in situ attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopic studies reveal that a favorable alkaline microenvironment for CO2RR to HCOOH is formed near the surface of Sn SACs, even in the acidic electrolyte. More importantly, the pH-dependent adsorption strength of *CO2 - intermediate is unravelled over the Sn SACs, which in turn affects the competition between HER and CO2RR in acidic electrolyte.

5.
Angew Chem Int Ed Engl ; 63(15): e202319882, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38337137

RESUMO

Polar materials with spontaneous polarization (Ps) have emerged as highly promising photocatalysts for efficient photocatalytic H2 evolution owing to the Ps-enhanced photogenerated carrier separation. However, traditional inorganic polar materials often suffer from limitations such as wide band gaps and poor carrier transport, which hinders their photocatalytic H2 evolution efficiency. Here, we rationally synthesized a series of isostructural two-dimensional (2D) aromatic Dion-Jacobson (DJ) perovskites, namely (2-(2-Aminoethyl)pyridinium)PbI4 (2-APDPI), (3-(2-Aminoethyl)pyridinium)PbI4 (3-APDPI), and (4-(2-Aminoethyl)pyridinium)PbI4 (4-APDPI), where 2-APDPI and 4-APDPI crystalize in polar space groups with piezoelectric constants (d33) of approximately 40 pm V-1 and 3-APDPI adopts a centrosymmetric structure. Strikingly, owing to the Ps-facilitated separation of photogenerated carriers, polar 2-APDPI and 4-APDPI exhibit a 3.9- and 2.8-fold increase, respectively, in photocatalytic H2 evolution compared to the centrosymmetric 3-APDPI. As a pioneering study, this work provides an efficient approach for exploring new polar photocatalysts and highlights their potential in promoting photocatalytic H2 evolution.

6.
Small ; 19(18): e2205781, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36775916

RESUMO

In this work, ethanol oxidation reaction (EOR) via 12-electron (C1-12e) pathway on spiky Au@AuPd nanoparticles (NPs) with ultrathin AuPd alloy shells is achieved in alkaline media with the assistance of the near-infrared (NIR) light. It is found that OH radicals can be produced from the OHads species adsorbed on the surfaces of Pd atoms led by surface plasmon resonance (SPR) effect of spiky Au@AuPd NPs under the irradiation of NIR light. Moreover, OH radicals play the key role for the achievement of EOR proceeded by the desirable C1-12e pathway because OH radicals can directly break the C-C bonds of ethanol. Accordingly, the electrocatalytic performance of spiky Au@AuPd NPs toward EOR under NIR light is greatly improved. For instance, their mass activity can be up to 33.2 A mgpd -1 in the 0.5 m KOH solution containing 0.5 m ethanol, which is about 158 times higher than that of commercial Pd/C catalysts (0.21 A mgpd -1 ) and is better than those of the state-of-the-art Pd-based catalysts reported in literature thus far, to the best of our knowledge. Moreover, their highest mass activity can be further improved to 118.3 A mgpd -1 in the 1.5 m KOH solution containing 1.25 m ethanol.

7.
Chemistry ; 29(25): e202203765, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-36752729

RESUMO

Photocatalytic hydrogen peroxide (H2 O2 ) production on BiVO4 photocatalysts using water and oxygen as raw materials is a green and sustainable process. However, the photocatalytic efficiency of pristine BiVO4 is limited by severe charge recombination. In this work, rare earth element Yttrium (Y) doped BiVO4 photocatalysts were fabricated by the hydrothermal method. In the photocatalytic H2 O2 production experiment, the optimized Y-doped BiVO4 photocatalyst produced 114 µmol g-1 h-1 of H2 O2 under simulated sunlight (AM1.5) irradiation, which is four times higher than production activity of pure BiVO4 (26 µmol g-1 h-1 ). Density functional theory (DFT) calculation revealed that Y doping can enhance oxygen adsorption on the BiVO4 photocatalyst surface. Mechanistic investigations suggest that the doping process induces the in situ formation of monoclinic/tetragonal BiVO4 heterojunction, which further promotes the photogenerated carriers separation efficiency.

8.
Chemistry ; 29(49): e202301478, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37332063

RESUMO

Electrochemical water splitting is an environmentally friendly and effective energy storage method. However, it is still a huge challenge to prepare non-noble metal based electrocatalysts that possess high activity and long-term durability to realize efficient water splitting. Here, we present a novel method of low-temperature phosphating for preparing CoP/Co3 O4 heterojunction nanowires catalyst on titanium mesh (TM) substrate that can be used for oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and overall water splitting. CoP/Co3 O4 @TM heterojunction showed an excellent catalytic performance and long-term durability in 1.0 M KOH electrolyte. The overpotential of CoP/Co3 O4 @TM heterojunction was only 257 mV at 20 mA cm-2 during the OER process, and it could work stably more than 40 h at 1.52 V versus reversible hydrogen electrode (vs. RHE). During the HER process, the overpotential of CoP/Co3 O4 @TM heterojunction was only 98 mV at -10 mA cm-2 . More importantly, when used as anodic and cathodic electrocatalyst, they achieved 10 mA cm-2 at 1.59 V. The Faradaic efficiencies of OER and HER were 98.4 % and 99.4 %, respectively, outperforming Ru/Ir-based noble metal electrocatalysts and other non-noble metal electrocatalysts for overall water splitting.

9.
Chemistry ; 29(41): e202300843, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37161702

RESUMO

In this work, a new method to extend the light absorption and improve the photocatalytic activity of metal-organic frameworks (MOFs) with nitrogen-containing ligand is reported, namely, the protonation of nitrogen. Specifically, a protonated Bi-based MOF synthesized by a hydrothermal method (Bi-MMTAA-H, MMTAA=2-mercapto-4-methyl-5-thiazoleacetic acid) displays a wider visible light absorption than Bi-MMTAA-R with the same single-crystal structure, but synthesized by a reflux method. The redshifted light absorption was confirmed to be caused by the protonation of nitrogen in the thiazolyl ring in MMTAA. Moreover, this protonation also facilitates the charge separation and transfer and improves the photocatalytic activity of selective oxidation of α-terpinene to p-cymene. Our results provide a new idea for nitrogen-containing Bi-based MOFs to extend the light absorption and improve the photocatalytic performance.

10.
Chemistry ; 29(39): e202300999, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37114518

RESUMO

Severe poisonousness and prolonged instability existing in organic-inorganic lead-based perovskite are two matters seriously hindering its potential future application in photocatalysis. Therefore, it is particularly important to explore ecology-friendly, air-stable and highly active metal-halide perovskites. Herein, a new and stable lead-free perovskite Cs2 SnBr6 decorated with reduced graphene oxide (rGO), is synthesized and employed in the photocatalytic organic conversion. The as-prepared Cs2 SnBr6 is ultrastable, exhibiting no clear changes after being placed in the air for six months. The Cs2 SnBr6 /rGO composite shows excellent photocatalytic activity in photo-driven-oxidation of 5-hydroxymethylfurfural (HMF) to high value enclosed 2,5-diformylfuran (DFF), achieving>99.5 % conversion of HMF and 88 % DFF selectivity in the presence of green oxidant O2 . Comprehensive characterizations disclose a multistep reaction mechanism, demonstrating that the molecular oxygen, photogenerated carriers, ⋅O2 - and 1 O2 altogether synergistically participate in the effective photo-driven conversion of HMF to DFF. This work expands the material gallery towards selective organic conversion and environmentally friendly perovskite options for photocatalytic application.

11.
Angew Chem Int Ed Engl ; 62(11): e202217569, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36658095

RESUMO

Electrochemical CO2 reduction reaction (CO2 RR) to chemical fuels such as formate offers a promising pathway to carbon-neutral future, but its practical application is largely inhibited by the lack of effective activation of CO2 molecules and pH-universal feasibility. Here, we report an electronic structure manipulation strategy to electron-rich Bi nanosheets, where electrons transfer from Cu donor to Bi acceptor in bimetallic Cu-Bi, enabling CO2 RR towards formate with concurrent high activity, selectivity and stability in pH-universal (acidic, neutral and alkaline) electrolytes. Combined in situ Raman spectra and computational calculations unravel that electron-rich Bi promotes CO2 ⋅- formation to activate CO2 molecules, and enhance the adsorption strength of *OCHO intermediate with an up-shifted p-band center, thus leading to its superior activity and selectivity of formate. Further integration of the robust electron-rich Bi nanosheets into III-V-based photovoltaic solar cell results in an unassisted artificial leaf with a high solar-to-formate (STF) efficiency of 13.7 %.

12.
Angew Chem Int Ed Engl ; 62(36): e202302919, 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37389483

RESUMO

Photoconversion of CO2 and H2 O into ethanol is an ideal strategy to achieve carbon neutrality. However, the production of ethanol with high activity and selectivity is challenging owing to the less efficient reduction half-reaction involving multi-step proton-coupled electron transfer (PCET), a slow C-C coupling process, and sluggish water oxidation half-reaction. Herein, a two-dimensional/two-dimensional (2D/2D) S-scheme heterojunction consisting of black phosphorus and Bi2 WO6 (BP/BWO) was constructed for photocatalytic CO2 reduction coupling with benzylamine (BA) oxidation. The as-prepared BP/BWO catalyst exhibits a superior photocatalytic performance toward CO2 reduction, with a yield of 61.3 µmol g-1 h-1 for ethanol (selectivity of 91 %).In situ spectroscopic studies and theoretical calculations reveal that S-scheme heterojunction can effectively promote photogenerated carrier separation via the Bi-O-P bridge to accelerate the PCET process. Meanwhile, electron-rich BP acts as the active site and plays a vital role in the process of C-C coupling. In addition, the substitution of BA oxidation for H2 O oxidation can further enhance the photocatalytic performance of CO2 reduction to C2 H5 OH. This work opens a new horizon for exploring novel heterogeneous photocatalysts in CO2 photoconversion to C2 H5 OH based on cooperative photoredox systems.

13.
Small ; 18(24): e2201269, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35567335

RESUMO

Direct ammonia (NH3 ) synthesis from water and atmospheric nitrogen using sunlight provides an energy-sustainable and carbon-neutral alternative to the Haber-Bosch process. However, the development of such a route with high performance is impeded by the lack of effective charge transfer and abundant active sites to initiate the nitrogen reduction reaction (NRR). Here, the authors report efficient plasmon-induced photoelectrochemical (PEC) NH3 synthesis on the hierarchical free-standing Au/Kx MoO3 /Mo/Kx MoO3 /Au nanoarrays. Endowed with energetically hot electrons and catalytically active sites, the plasmonic nanoarrays exhibit an efficient PEC NH3 synthesis rate of 9.6 µg cm-2 h-1 under visible light irradiation, which is among the highest PEC NRR systems. This work demonstrates the rationally designed plasmonic nanoarrays for highly efficient NH3 synthesis, which paves a new path for PEC catalytic reactions driven by surface plasmons and future monolithic PEC devices for direct artificial photosynthesis.


Assuntos
Amônia , Elétrons , Catálise , Domínio Catalítico , Nitrogênio
14.
Small ; 18(9): e2105212, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34918468

RESUMO

The electrochemical CO2 reduction reaction (CO2 RR) has great potential in realizing carbon recycling while storing sustainable electricity as hydrocarbon fuels. However, it is still a challenge to enhance the selectivity of the CO2 RR to single multi-carbon (C2+ ) product, such as C2 H4 . Here, an effective method is proposed to improve C2 H4 selectivity by inhibiting the production of the other competitive C2 products, namely C2 H5 OH, from Cu2 O/C composite. Density functional theory indicates that the heterogeneous structure between Cu2 O and carbon is expected to inhibit C2 H5 OH production and promote CC coupling, which facilitates C2 H4 production. To prove this, a composite electrode containing octahedral Cu2 O nanoparticles (NPs) (o-Cu2 O) with {111} facets and carbon NPs is constructed, which experimentally inhibits C2 H5 OH production while strongly enhancing C2 H4 selectivity compared with o-Cu2 O electrode. Furthermore, the surface hydroxylation of carbon can further improve the C2 H4 production of o-Cu2 O/C electrode, exhibiting a high C2 H4 Faradaic efficiency of 67% and a high C2 H4 current density of 45 mA cm-2 at -1.1 V in a near-neutral electrolyte. This work provides a new idea to improve C2+ selectivity by controlling products desorption.

15.
Chemistry ; 28(50): e202201095, 2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-35730468

RESUMO

Lead halide perovskite has triggered a lot of research due to its superior optical properties. However, halide perovskite materials have poor environmental stabilities and are easily affected by external factors such as water and heat, resulting in structural decomposition and performance failure. Contrary to this commonplace concept, it is found that CsPbBr3 (CPB) can convert to CsPb2 Br5 (CP2B5) partially when meeting a small amount of water, and the CsPbBr3 @CsPb2 Br5 (CPB@CP2B5) composite is synthesized by an in situ method accordingly. The CPB@CP2B5 composite shows an enhanced catalytic performance compared with pure CPB, as well as a dramatically synergistic effect of photo and thermal for catalytic CO2 hydrogenation. The CO production rate of CPB@CP2B5 is determined as 69 µmol g-1 h-1 under light irradiation at 200 °C, which is 156.8 and 43.4 times higher than that under pure photo (0.44 µmol g-1 h -1 ) and pure thermal (1.59 µmol g-1 h -1 ) condition, respectively. Meanwhile, the CPB@CP2B5 sample is also stable, which shows no significant decline in the catalytic activity during 8 cycles of repeated experiments. The probable mechanism is explored by utilizing a series of in situ characterizations.

16.
Inorg Chem ; 61(29): 11110-11117, 2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35815803

RESUMO

In this work, a Bi-based metal-organic framework (MOF; Bi-MMTAA) with 2-mercapto-4-methyl-5-thiazoleacetic acid (MMTAA) as the organic ligand is synthesized. The crystal structure of Bi-MMTAA was determined by single-crystal X-ray diffraction. Theoretical calculations reveal that Bi-MMTAA is a p-type semiconductor, and electrons can delocalize through the π-conjugation when excited by a photon with an energy higher than the Bi-MMTAA band gap, which is beneficial to charge separation and transfer. The photoelectrical properties suggest that free electrons can be produced over Bi-MMTAA under light irradiation. The photocatalytic results suggest that Bi-MMTAA can decolorize rhodamine B (RhB) and oxidize phenylboronic acid to phenol under visible light (λ > 420 nm), with superoxide radicals being the main reactive oxygen species. Our results enrich the family of Bi-based MOFs and may inspire further exploration of Bi-based MOFs, including both synthesis and potential applications.

17.
Angew Chem Int Ed Engl ; 61(41): e202209446, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-35989227

RESUMO

Selective CO2 photoreduction to hydrocarbon fuels such as CH4 is promising and sustainable for carbon-neutral future. However, lack of proper binding strengths with reaction intermediates makes it still a challenge for photocatalytic CO2 methanation with both high activity and selectivity. Here, low-coordination single Au atoms (Au1 -S2 ) on ultrathin ZnIn2 S4 nanosheets was synthesized by a complex-exchange route, enabling exceptional photocatalytic CO2 reduction performance. Under visible light irradiation, Au1 /ZnIn2 S4 catalyst exhibits a CH4 yield of 275 µmol g-1 h-1 with a selectivity as high as 77 %. As revealed by detailed characterizations and density functional theory calculations, Au1 /ZnIn2 S4 with Au1 -S2 structure not only display fast carrier transfer to underpin its superior activity, but also greatly reduce the energy barrier for protonation of *CO and stabilize the *CH3 intermediate, thereby leading to the selective CH4 generation from CO2 photoreduction.

18.
Nano Lett ; 20(5): 3326-3330, 2020 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-32315532

RESUMO

Understanding the underlying kinetic mechanism of plasmon-enhanced catalysis is important for designing optimized bimetal nanostructures. Here, we characterize product formation rate at both the single-particle and ensemble level. The single-particle measurement allows us to reveal the underlying catalytic kinetic mechanisms of a bimetal nanostructure. Combining this with ensemble observations of two different catalytic behaviors of this catalyst with and without illumination shows that energetic charge carriers induce a transition from a competitive reactant adsorption type to a noncompetitive adsorption type, which leads to the suppression of catalytic rate decay at high reactant concentration. Theoretical modeling as well as analysis of hole acceptability of scavengers on Pt and Au surfaces indicates that the Pt light absorptivity is enhanced near Au and the energetic charges may form directly from the Pt part of the Au-Pt nanostructure. The presented study deepens our understanding of plasmon-enhanced catalysis by bimetal nanostructures.

19.
Inorg Chem ; 59(22): 16127-16131, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33147007

RESUMO

For Ag(I)-based photocatalysts, the photoreduction of Ag+ to metallic Ag is an unignorable issue, which is the major reason for their instability. If electrically neutral excitons rather than electrons were produced over Ag(I)-based photocatalysts, the photoreduction of Ag+ is expected to be greatly suppressed. To check this assumption, a Ag-based metal-organic framework containing pyrene, which is in favor of exciton production, is synthesized (denoted as Ag-PTS-BPY) and the structure is solved via single-crystal X-ray diffraction. Ag-PTS-BPY is applied in the photocatalytic selective oxidation of methyl phenyl sulfide, which displays high conversion and selectivity. As expected, no metallic Ag is formed after five cycles of reaction according to the results of X-ray diffraction, Fourier transform infrared, and X-ray photoelectron spectroscopy, and the high conversion is also maintained. The participation of excitons suppresses the involvement of electrons, which are believed to be the reason for the high stability of Ag-PTS-BPY.

20.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(5): 447-450, 2019 May 10.
Artigo em Zh | MEDLINE | ID: mdl-31030430

RESUMO

OBJECTIVE: To explore the genetic etiology of two pedigrees affected with congenital arthrogryposis. METHODS: Whole exome sequencing (WES) was used to screen potential variations in the proband. Suspected variations were analyzed with bioinformatics software and validated by Sanger sequencing. RESULTS: A heterozygous c.1123G>A (p.Glu375Lys) variation was detected in the proband and an affected fetus from pedigree 1, while a de novo heterozygous c.118 G>A (p.Val40Met) variation was detected in an affected fetus from pedigree 2. CONCLUSION: The two heterozygous variations of the MYH3 gene probably underlie the disease in the pedigrees. Above results have facilitated genetic counseling and prenatal diagnosis.


Assuntos
Artrogripose , Proteínas do Citoesqueleto/genética , Feminino , Heterozigoto , Humanos , Mutação , Linhagem , Gravidez , Diagnóstico Pré-Natal , Sequenciamento do Exoma
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