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1.
Cell ; 180(6): 1228-1244.e24, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32142649

RESUMO

Transcription-coupled nucleotide excision repair (TC-NER) is initiated by the stalling of elongating RNA polymerase II (RNAPIIo) at DNA lesions. The ubiquitination of RNAPIIo in response to DNA damage is an evolutionarily conserved event, but its function in mammals is unknown. Here, we identified a single DNA damage-induced ubiquitination site in RNAPII at RPB1-K1268, which regulates transcription recovery and DNA damage resistance. Mechanistically, RPB1-K1268 ubiquitination stimulates the association of the core-TFIIH complex with stalled RNAPIIo through a transfer mechanism that also involves UVSSA-K414 ubiquitination. We developed a strand-specific ChIP-seq method, which revealed RPB1-K1268 ubiquitination is important for repair and the resolution of transcriptional bottlenecks at DNA lesions. Finally, RPB1-K1268R knockin mice displayed a short life-span, premature aging, and neurodegeneration. Our results reveal RNAPII ubiquitination provides a two-tier protection mechanism by activating TC-NER and, in parallel, the processing of DNA damage-stalled RNAPIIo, which together prevent prolonged transcription arrest and protect against neurodegeneration.


Assuntos
Reparo do DNA/fisiologia , RNA Polimerase II/metabolismo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , DNA/metabolismo , Dano ao DNA/fisiologia , DNA Helicases/metabolismo , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Feminino , Células HCT116 , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Polimerase II/genética , Ubiquitinação
2.
Proc Natl Acad Sci U S A ; 120(24): e2301312120, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37279269

RESUMO

Glycan alterations are associated with aging, neuropsychiatric, and neurodegenerative diseases, although the contributions of specific glycan structures to emotion and cognitive functions remain largely unknown. Here, we used a combination of chemistry and neurobiology to show that 4-O-sulfated chondroitin sulfate (CS) polysaccharides are critical regulators of perineuronal nets (PNNs) and synapse development in the mouse hippocampus, thereby affecting anxiety and cognitive abilities such as social memory. Brain-specific deletion of CS 4-O-sulfation in mice increased PNN densities in the area CA2 (cornu ammonis 2), leading to imbalanced excitatory-to-inhibitory synaptic ratios, reduced CREB activation, elevated anxiety, and social memory dysfunction. The impairments in PNN densities, CREB activity, and social memory were recapitulated by selective ablation of CS 4-O-sulfation in the CA2 region during adulthood. Notably, enzymatic pruning of the excess PNNs reduced anxiety levels and restored social memory, while chemical manipulation of CS 4-O-sulfation levels reversibly modulated PNN densities surrounding hippocampal neurons and the balance of excitatory and inhibitory synapses. These findings reveal key roles for CS 4-O-sulfation in adult brain plasticity, social memory, and anxiety regulation, and they suggest that targeting CS 4-O-sulfation may represent a strategy to address neuropsychiatric and neurodegenerative diseases associated with social cognitive dysfunction.


Assuntos
Matriz Extracelular , Doenças Neurodegenerativas , Camundongos , Animais , Matriz Extracelular/química , Neurônios/fisiologia , Hipocampo , Sulfatos de Condroitina/química
3.
Proc Natl Acad Sci U S A ; 120(43): e2301811120, 2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-37844225

RESUMO

In the context of elevated concerns related to nuclear accidents and warfare, the lessons learnt from the Fukushima Daiichi Nuclear Power Plant accident in 2011 are important. In particular, Japanese authorities implemented an ambitious decontamination program to reduce the air dose rate in order to facilitate the return of the local inhabitants to previously evacuated areas. This approach contrasts the strategy adopted in Chernobyl, where the most contaminated areas remain off limits. Nonetheless, the effectiveness of the Japanese decontamination strategy on the dispersion of radioactive contaminant fluxes across mountainous landscapes exposed to typhoons has not been quantified. Based on the unique combination of river monitoring and modeling in a catchment representative of the most impacted area in Japan, we demonstrate that decontamination of 16% of the catchment area resulted in a decrease of 17% of sediment-bound radioactive fluxes in rivers. Decontamination operations were therefore relatively effective, although they could only be conducted in a small part of the area due to the dominance of steep forested slopes. In fact, 67% of the initial radiocesium contamination was calculated to remain stored in forested landscapes, which may contribute to future downstream radiocesium dispersion during erosive events. Given that only a limited proportion of the initial population had returned in 2019 (~30%), it raises the question as to whether decontaminating a small percentage of the contaminated area was worth the effort, the price, and the amount of waste generated?


Assuntos
Acidente Nuclear de Fukushima , Monitoramento de Radiação , Poluentes Radioativos do Solo , Poluentes Radioativos da Água , Radioisótopos de Césio/análise , Descontaminação , Poluentes Radioativos da Água/análise , Poluentes Radioativos do Solo/análise , Japão
4.
J Biol Chem ; 300(1): 105539, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38072054

RESUMO

L-ergothioneine is widely distributed among various microbes to regulate their physiology and pathogenicity within complex environments. One of the key steps in the ergothioneine-biosynthesis pathway, the C-S bond cleavage reaction, uses the pyridoxal 5'-phosphate dependent C-S lyase to produce the final product L-ergothioneine. Here, we present the crystallographic structure of the ergothioneine-biosynthesis C-S lyase EgtE from Mycobacterium smegmatis (MsEgtE) represents the first published structure of ergothioneine-biosynthesis C-S lyases in bacteria and shows the effects of active site residues on the enzymatic reaction. The MsEgtE and the previously reported ergothioneine-biosynthesis C-S lyase Egt2 from Neurospora crassa (NcEgt2) fold similarly. However, discrepancies arise in terms of substrate recognition, as observed through sequence and structure comparison of MsEgtE and NcEgt2. The structural-based sequence alignment of the ergothioneine-biosynthesis C-S lyase from fungi and bacteria shows clear distinctions among the recognized substrate residues, but Arg348 is critical and an extremely conserved residue for substrate recognition. The α14 helix is exclusively found in the bacteria EgtE, which represent the most significant difference between bacteria EgtE and fungi Egt2, possibly resulting from the convergent evolution of bacteria and fungi.


Assuntos
Ergotioneína , Liases , Mycobacterium , Ergotioneína/química , Ergotioneína/metabolismo , Fungos/metabolismo , Liases/química , Liases/metabolismo , Mycobacterium/metabolismo , Mycobacterium smegmatis/química , Mycobacterium smegmatis/enzimologia , Modelos Moleculares , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína
5.
Circulation ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38666382

RESUMO

BACKGROUND: The clinical application of human induced pluripotent stem cell-derived cardiomyocytes (CMs) for cardiac repair commenced with the epicardial delivery of engineered cardiac tissue; however, the feasibility of the direct delivery of human induced pluripotent stem cell-derived CMs into the cardiac muscle layer, which has reportedly induced electrical integration, is unclear because of concerns about poor engraftment of CMs and posttransplant arrhythmias. Thus, in this study, we prepared purified human induced pluripotent stem cell-derived cardiac spheroids (hiPSC-CSs) and investigated whether their direct injection could regenerate infarcted nonhuman primate hearts. METHODS: We performed 2 separate experiments to explore the appropriate number of human induced pluripotent stem cell-derived CMs. In the first experiment, 10 cynomolgus monkeys were subjected to myocardial infarction 2 weeks before transplantation and were designated as recipients of hiPSC-CSs containing 2×107 CMs or the vehicle. The animals were euthanized 12 weeks after transplantation for histological analysis, and cardiac function and arrhythmia were monitored during the observational period. In the second study, we repeated the equivalent transplantation study using more CMs (6×107 CMs). RESULTS: Recipients of hiPSC-CSs containing 2×107 CMs showed limited CM grafts and transient increases in fractional shortening compared with those of the vehicle (fractional shortening at 4 weeks after transplantation: 26.2±2.1%; 19.3±1.8%; P<0.05), with a low incidence of posttransplant arrhythmia. Transplantation of increased dose of CMs resulted in significantly greater engraftment and long-term contractile benefits (fractional shortening at 12 weeks after transplantation: 22.5±1.0%; 16.6±1.1%; P<0.01, left ventricular ejection fraction at 12 weeks after transplantation: 49.0±1.4%; 36.3±2.9%; P<0.01). The incidence of posttransplant arrhythmia slightly increased in recipients of hiPSC-CSs containing 6×107 CMs. CONCLUSIONS: We demonstrated that direct injection of hiPSC-CSs restores the contractile functions of injured primate hearts with an acceptable risk of posttransplant arrhythmia. Although the mechanism for the functional benefits is not fully elucidated, these findings provide a strong rationale for conducting clinical trials using the equivalent CM products.

6.
Proc Natl Acad Sci U S A ; 119(22): e2202449119, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35622888

RESUMO

Organodisulfides (RSSR) are a class of promising active materials for redox flow batteries (RFBs). However, their sluggish kinetics and poor cyclic stability remain a formidable challenge. Here, we propose carbon disulfide (CS2) as a unique redox mediator involving reversible C-S bond formation/breakage to facilitate the reduction reaction of organodisulfides in RFBs. In the discharge of RSSR, CS2 interacts with the negatively charged RSSR-• to promote cleavage of the S-S bond by reducing about one-third of the energy barrier, forming RSCS2Li. In the recharge, CS2 is unbonded from RSCS2Li while RSSR is regenerated. Meanwhile, the redox mediator can also be inserted into the molecular structure of RSSR to form RSCS2SR/RSCS2CS2SR, and these new active materials with lower energy barriers can further accelerate the reaction kinetics of RSSR. With CS2, phenyl disulfide exhibits an exceptional rate capability and cyclability of 500 cycles. An average energy efficiency of >90% is achieved. This strategy provides a unique redox-mediating pathway involving C-S bond formation/breakage with the active species, which is different from those used in lithium-oxygen or other batteries.

7.
Nano Lett ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950105

RESUMO

Molybdenum disulfide (MoS2) is one of the most intriguing two-dimensional materials, and moreover, its single atomic defects can significantly alter the properties. These defects can be both imaged and engineered using spherical and chromatic aberration-corrected high-resolution transmission electron microscopy (CC/CS-corrected HRTEM). In a few-layer stack, several atoms are vertically aligned in one atomic column. Therefore, it is challenging to determine the positions of missing atoms and the damage cross-section, particularly in the not directly accessible middle layers. In this study, we introduce a technique for extracting subtle intensity differences in CC/CS-corrected HRTEM images. By exploiting the crystal structure of the material, our method discerns chalcogen vacancies even in the middle layer of trilayer MoS2. We found that in trilayer MoS2 the middle layer's damage cross-section is about ten times lower than that in the monolayer. Our findings could be essential for the application of few-layer MoS2 in nanodevices.

8.
Plant J ; 114(4): 951-964, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36919360

RESUMO

Red coloration around the stone (Cs) is an important trait of canned peaches (Prunus persica). In this study, an elongated hypocotyl 5 gene in peach termed PpHY5 was identified to participate in the regulation of the Cs trait. The E3 ubiquitin ligase PpCOP1 was expressed in the flesh around the stone and could interact with PpHY5. Although HY5 is known to be degraded by COP1 in darkness, the PpHY5 gene was activated in the flesh tissue surrounding the stone at the ripening stages and its expression was consistent with anthocyanin accumulation. PpHY5 was able to promote the transcription of PpMYB10.1 through interacting with its partner PpBBX10. Silencing of PpHY5 in the flesh around the stone caused a reduction in anthocyanin pigmentation, while transient overexpression of PpHY5 and PpBBX10 resulted in anthocyanin accumulation in peach fruits. Moreover, transgenic Arabidopsis seedlings overexpressing PpHY5 showed increased anthocyanin accumulation in leaves. Our results improve our understanding of the mechanisms of anthocyanin coloration in plants.


Assuntos
Arabidopsis , Prunus persica , Prunus persica/genética , Prunus persica/metabolismo , Fatores de Transcrição/metabolismo , Antocianinas/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Folhas de Planta/metabolismo , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Frutas/genética , Frutas/metabolismo
9.
Cancer ; 130(11): 1991-2002, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38404184

RESUMO

BACKGROUND: This study investigated the safety and efficacy of an anti-CTLA-4 monoclonal antibody (CS1002) as monotherapy and in combination with an anti-PD-1 monoclonal antibody (CS1003) in patients with advanced/metastatic solid tumors. METHODS: The phase 1 study involved phase 1a monotherapy dose-escalation (part 1) and phase 1b combination therapy dose escalation (part 2) and expansion (part 3). Various dosing schedules of CS1002 (0.3, 1, or 3 mg/kg every 3 weeks, or 3 mg/kg every 9 weeks) were evaluated with 200 mg CS1003 every 3 weeks in part 3. RESULTS: Parts 1, 2, and 3 included a total of 13, 18, and 61 patients, respectively. No dose-limiting toxicities or maximum tolerated doses were observed. Treatment-related adverse events (TRAEs) were reported in 30.8%, 83.3%, and 75.0% of patients in parts 1, 2, and 3, respectively. Grade ≥3 TRAEs were experienced by 15.4%, 50.0%, and 18.3% of patients in each part. Of 61 patients evaluable for efficacy, 23 (37.7%) achieved objective responses in multiple tumor types. Higher objective response rates were observed with conventional and high-dose CS1002 regimens (1 mg/kg every 3 weeks or 3 mg/kg every 9 weeks) compared to low-dose CS1002 (0.3 mg/kg every 3 weeks) in microsatellite instability-high/mismatch repair-deficient tumors, melanoma, and hepatocellular carcinoma (50.0% vs. 58.8%, 14.3% vs. 42.9%, and 0% vs. 16.7%). CONCLUSION: CS1002, as monotherapy, and in combination with CS1003, had a manageable safety profile across a broad dosing range. Promising antitumor activities were observed in patients with immune oncology (IO)-naive and IO-refractory tumors across CS1002 dose levels when combined with CS1003, supporting further evaluation of this treatment combination for solid tumors. PLAIN LANGUAGE SUMMARY: CS1002 is a human immunoglobulin (Ig) G1 monoclonal antibody that blocks the interaction of CTLA-4 with its ligands and increases T-cell activation/proliferation. CS1003, now named nofazinlimab, is a humanized, recombinant IgG4 monoclonal antibody that blocks the interaction between human PD-1 and its ligands. In this original article, we determined the safety profile of CS1002 as monotherapy and in combination with CS1003. Furthermore, we explored the antitumor activity of the combination in anti-programmed cell death protein (ligand)-1 (PD-[L]1)-naive microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) pan tumors, and anti-PD-(L)1-refractory melanoma and hepatocellular carcinoma (HCC). CS1002 in combination with CS1003 had manageable safety profile across a broad dosing range and showed promising antitumor activities across CS1002 dose levels when combined with CS1003. This supports further assessment of CS1002 in combination with CS1003 for the treatment of solid tumors.


Assuntos
Anticorpos Monoclonais Humanizados , Antígeno CTLA-4 , Inibidores de Checkpoint Imunológico , Neoplasias , Receptor de Morte Celular Programada 1 , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Antígeno CTLA-4/antagonistas & inibidores , Antígeno CTLA-4/imunologia , Idoso , Adulto , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/administração & dosagem , Inibidores de Checkpoint Imunológico/efeitos adversos , Anticorpos Monoclonais Humanizados/administração & dosagem , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/efeitos adversos , Dose Máxima Tolerável , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
10.
Small ; : e2309922, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38593357

RESUMO

Self-trapped exciton (STE) luminescence, typically associated with structural deformation of excited states, has attracted significant attention in metal halide materials recently. However, the mechanism of multiexciton STE emissions in certain metal halide crystals remains largely unexplored. This study investigates dual luminescence emissions in HCOO- doped Cs3Cu2I5 single crystals using transient and steady-state spectroscopy. The dual emissions are attributed to intrinsic STE luminescence originating from the host lattice and extrinsic STE luminescence induced by external dopants, respectively, each of which can be triggered independently at distinct energy levels. Theoretical calculations reveal that multiexciton emission originates from structural distortion of the host and dopant STEs within the 0D lattice in their respective excited states. By meticulously tuning the excitation wavelength and selectively exciting different STEs, the dynamic alteration of color change in Cs3Cu2I5:HCOO- crystals is demonstrated. Ultimately, owing to an extraordinarily high photoluminescence quantum yield (99.01%) and a diminished degree of self-absorption in Cs3Cu2I5:HCOO- crystals, they exhibit remarkable X-ray scintillation characteristics with light yield being improved by 5.4 times as compared to that of pristine Cs3Cu2I5 crystals, opening up exciting avenues for achieving low-dose X-ray detection and imaging.

11.
Small ; : e2403648, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38881372

RESUMO

CsPbBr3@Cs4PbBr6 hexagonal NCs with a bright photoluminescence (PL) peak of 456 nm are created through the dissolution-recrystallization of CsPbBr3 nanoplatelets. Small CsPbBr3 nanocrystals are encapsulated in hexagonal Cs4PbBr6 during recrystallization to form a core-shell structure and keep high brightness and stability. The recrystallization kinetics is systematically investigated to explore the roles of methyl acetate, oleylamine, and n-hexane. Result further indicates that core/shell NCs remained high PL under a variety of harsh conditions (e.g., light irradiation and heat treatment) because of Cs4PbX6 shell and the controlling of recrystallization. Their initial PL intensity is remained after 4 months of storage under ambient conditions and continuous exposure to UV lamp for 180 min. The bright PL is also maintained even treatment at 120 °C. To indicate the universality of this synthesis method, CsPbX3@Cs4PbX6 hexagonal NCs with different emission colors are fabricated by changing temperature, solvent viscosity, and precursors (e,g, oleylamine and halogens). These core-shell samples reveal bright and stable green, orange, and red PL. Because of its high stability, the core/shell NCs are dispersed in flexible films to create diverse patterns. The films also exhibit high brightness and excellent stability. This strategy opens a novel avenue for the application of perovskite nanomaterials in the display field.

12.
Small ; 20(27): e2310915, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38267813

RESUMO

Lithium dendrites are easily generated for excessively-solved lithium ions (Li+) inside the lithium metal batteries, which will lead serious safety issues. In this experiment, carbon spheres (CS) are successfully anchored on TiO2 (CS@TiO2) in the hydrothermal polymerization, which is filtrated on the commercial PE separator (CS@TiO2@PE). The negative charge in CS can suppress random diffusion of anions through electrostatic interactions. Density functional theory (DFT) calculations show that CS contributes to the desolvation of Li+, thereby increasing the migration rate of Li+. Furthermore, TiO2 exhibits high affinity to liquid electrolytes and acts as a physical barrier to lithium dendrite formation. CS@TiO2 is a combination of the advantages of CS and TiO2. As results, the Li+ transference number of the CS@TiO2@PE separator can be promoted to 0.63. The Li||Li cell with the CS@TiO2@PE separator exhibits a stable cycle performance for more than 600 h and lower polarization voltage (17 mV) at 1 mA cm-2. The coulombic efficiency (CE) of the Li||Cu cells employe the CS@TiO2@PE separator is 81.63% over 130 cycles. The discharge capacity of LiFePO4||Li cells based on the CS@TiO2@PE separator is 1.73 mAh (capacity retention = 91.53% after 260 cycles). Thus, the CS@TiO2 layer inhibits lithium dendrite formation.

13.
Small ; : e2401202, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38805739

RESUMO

Halide perovskites have garnered significant attention for their unique optoelectronic properties in solar-to-fuel conversions. However, the efficiency of halide perovskites in the field of photocatalytic CO2 reduction is largely limited by serious charge recombination and a lack of efficient active sites. In this work, a rubidium (Rb) doped Cs2AgBiBr6 (Rb:CABB) hierarchical microsphere is developed for photocatalytic CO2 reduction. Experimental and theoretical analysis discloses that partially substituting Rb+ for Ag+ can effectively modulate the electronic structure of CABB, favoring charge separation and making adjacent Bi atoms an electron-rich active site. Further investigations indicated that Rb doping also reduces the energy barriers of the rate-determining step in CO2 reduction. As a result, Rb:CABB demonstrated an enhanced CO yield compared to its undoped counterpart. This work presents a promising approach to optimizing the electronic structures of photocatalysts and paving a new way for exploring halide perovskites for photocatalytic CO2 reduction.

14.
Small ; : e2402268, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38733239

RESUMO

A high-quality nanostructured tin oxide (SnO2) has garnered massive attention as an electron transport layer (ETL) for efficient perovskite solar cells (PSCs). SnO2 is considered the most effective alternative to titanium oxide (TiO2) as ETL because of its low-temperature processing and promising optical and electrical characteristics. However, some essential modifications are still required to further improve the intrinsic characteristics of SnO2, such as mismatch band alignments, charge extraction, transportation, conductivity, and interfacial recombination losses. Herein, an inorganic-based cesium (Cs) dopant is used to modify the SnO2 ETL and to investigate the impact of Cs-dopant in curing interfacial defects, charge-carrier dynamics, and improving the optoelectronic characteristics of PSCs. The incorporation of Cs contents efficiently improves the perovskite film quality by enhancing the transparency, crystallinity, grain size, and light absorption and reduces the defect states and trap densities, resulting in an improved power conversion efficiency (PCE) of ≈22.1% with Cs:SnO2 ETL, in-contrast to pristine SnO2-based PSCs (20.23%). Moreover, the Cs-modified SnO2-based PSCs exhibit remarkable environmental stability in a relatively higher relative humidity environment (>65%) and without encapsulation. Therefore, this work suggests that Cs-doped SnO2 is a highly favorable electron extraction material for preparing highly efficient and air-stable planar PSCs.

15.
Small ; : e2402410, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38766970

RESUMO

Lead-free halide perovskites as a new kind of potential candidate for photocatalytic organic synthesis have attracted much attention recently. The rational heterojunction construction is regarded as an efficient strategy to delicately regulate their catalytic performances. Herein, a semi-conductive covalent organic framework (COF) nanosheet, C4N, is employed as the functional component to construct Cs2AgBiCl6/C4N (CABC/C4N) heterojunction. It is found that the C4N nanosheets with rich surface functional groups can serve as heterogeneous nucleation sites to manipulate the growth of CABC nanocrystals and afford close contact between each other, therefore facilitate the transfer and spatial separation of photogenerated charge carriers, as verified by in situ X-ray photoelectronic spectroscopy and Kelvin probe force microscopy. Moreover, the oxygen affinity of C4N endows the heterojunctions with outstanding aerobic reactivity, thus improving the photocatalytic performance largely. The optimal CABC/C4N heterojunction delivers a thioanisole conversion efficiency of 100% after 6 h, which is 2.2 and 7.7-fold of that of CABC and C4N. This work provides a new ideal for the design and application of lead-free perovskite heterojunction photocatalysts for organic reactions.

16.
Small ; 20(1): e2304756, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37653605

RESUMO

Halide perovskites exhibit outstanding optoelectronic properties, which make them an ideal choice for photocatalytic CO2 reduction and benzyl alcohol (BA) oxidation. Nevertheless, the simultaneous realization of the above redox coupling reactions on halide perovskites remains a great challenge, as it requires distinct catalytic sites for different target reactions. Herein, the catalytic sites of Cs2 AgBiCl6 (CABC) are regulated by doping Fe for efficient coupling of photocatalytic CO2 reduction and BA oxidation. The Fe-doped CABC (Fe: CABC) exhibits an enhanced visible-light response and effective charge separation. Experimental results and theoretical calculations reveal a synergistic interplay between Bi and Fe sites, where the Bi and Fe sites have lower activation energies toward CO2 reduction and BA oxidation. Further investigations demonstrate that electrons and holes prefer to accumulate at the Bi site and Fe site under light irradiation, respectively, which creates favorable conditions for facilitating CO2 reduction and BA oxidation. The resultant Fe: CABC achieves a high photocatalytic performance toward CO (18.5 µmol g-1  h-1 ) and BD (1.1 mmol g-1  h-1 ) generation, which surpasses most of the state-of-the-art halide photocatalysts. This work demonstrates a facile strategy for regulating the catalytic site for redox coupling reactions, which will pave a new way for designing halide perovskites for photocatalysis.

17.
Small ; 20(2): e2305566, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37661354

RESUMO

Regulating the built-in electric field (BEF) in the heterojunction is is a great challenge in developing high-efficiency photocatalysts. Herein, by tailoring the content of oxygen vacancies in the constituent reduction semiconductor (mesoporous CeO2-x ), a precise Fermi level (EF ) regulation of CeO2-x is realized, yielding an amplified EF gap and intensified BEF in the Cs3 Bi2 Br9 perovskite quantum dots/CeO2-x S-scheme heterojunction. Such an enhanced BEF offers a strong driving force for directional electron transfer, boosting charge separation in the S-scheme heterojunction. As a result, the optimized Cs3 Bi2 Br9 /CeO2-x heterojunction delivers a remarkable CO2 conversion efficiency, with an impressive CO production rate of 80.26 µmol g-1  h-1 and a high selectivity of 97.6%. The S-scheme charge transfer mode is corroborated comprehensively by density functional theory (DFT) calculations, in situ X-ray photoelectron spectroscopy (XPS), and photo-irradiated Kelvin probe force microscopy (KPFM). Moreover, diffuse reflectance infrared Fourier transform spectra (DRIFTS) and theoretical calculations are conducted cooperatively to reveal the CO2 photoreduction pathway.

18.
Small ; : e2400763, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864211

RESUMO

The Cs3Bi2I9 single crystal, as an all-inorganic non-lead perovskite, offers advantages such as stability and environmental friendliness. Its superior photoelectric properties, attributed to the absence of grain boundary influence, make it an outstanding X-ray detection material compared to polycrystals. In addition to material properties, X-ray detector performance is affected by the thickness of the absorption layer. Addressing this, a space-confined method is proposed. The temperature field is determined through finite element simulation, effectively guiding the design of the space-confined method. Through this innovative method, a series of thickness-controlled perovskite single crystal wafers (PSCWs) are successfully prepared. Corresponding X-ray detectors are then prepared, and the impact of single crystal thickness on device performance is investigated. With an increase in single crystal thickness, a rise followed by a decline in device sensitivity is observed, reaching an optimal value at 0.7 mm thickness at 40V mm-1 with a device performance of 11313.6µC Gy-1 cm-2. This space-confined method enables the direct growth of high-quality perovskite single crystals with specified thickness, eliminating the need for slicing or etching.

19.
Small ; : e2401601, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38554021

RESUMO

Photothermal catalysis, which applies solar energy to produce photogenerated e-/h+ pairs as well as provide heat input, is recognized as a promising technology for high conversion efficiency of CO2 to value-added solar fuels. In this work, a "shooting three birds with one stone" approach is demonstrated to significantly enhance the photothermal CO2 reduction over the Cs3Bi2Br9@Co3O4 (CBB@Co3O4) heterostructure. Initially, Co3O4 with photoinduced self-heating effect serves as a photothermal material to elevate the temperature of the photocatalyst, which kinetically accelerates the catalytic reaction. Meanwhile, a p-n heterojunction is constructed between the p-type Co3O4 and n-type Cs3Bi2Br9 semiconductors, which has an intrinsic built-in electric field (BEF) to facilitate the separation of photogenerated e-/h+ pairs. Furthermore, the mesoporous Co3O4 matrix can afford abundant active sites for promoting adsorption/activation of CO2 molecules. Benefiting from these synergistic effects, the as-developed CBB@Co3O4 heterostructure achieves an impressive CO2-to-CO conversion rate of 168.56 µmol g-1 h-1 with no extra heat input. This work provides an insightful guidance for the construction of effective photothermal catalysts for CO2 reduction with high solar-to-fuel conversion efficiency.

20.
Small ; 20(22): e2309107, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38145322

RESUMO

Synthesis of upconversion nanoparticles (UCNPs)-metal halide perovskites (MHPs) heterostructure is garnered immense attentions due to their unparalleled photophysical properties. However, the obvious difference in their structural forms makes it a huge challenge. Herein, hexagonal ß-NaYF4 and hexagonal Cs4PbBr6 are filtrated to construct the UCNP/MHP heterostructural luminescent material. The similarity in their crystal structures facilitate the heteroepitaxial growth of Cs4PbBr6 on the surface of ß-NaYF4 NPs, leading to the formation of high-quality ß-NaYF4:Yb,Tm/Cs4PbBr6 core/shell nanocrystals (NCs). Interestingly, this heterostructure endows the core/shell NCs with typically narrow-band green emission centered at 524 nm under 980 nm excitation, which should be attributed to the Förster resonance energy transfer (FRET) from Tm3+ to Cs4PbBr6. It is noteworthy that the FRET efficiency of ß-NaYF4:Yb,Tm/Cs4PbBr6 core/shell NCs (58.33%) is much higher than that of the physically mixed sample (1.84%). In addition, the reduced defect density, lattice anchoring effect, as well as diluted ionic bonding proportion induced by the core/shell structure further increase the excellent water-resistance and thermal cycling stability of Cs4PbBr6. These findings open up a new way to construct UCNP/MHP heterostructure with better multi-code luminescence performance and stability and promote its wide optoelectronic applications.

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