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1.
Adv Mater ; : e2403328, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38586929

RESUMO

Metal-organic frameworks (MOFs) have emerged as promising platforms for photocatalytic hydrogen evolution reaction (HER) due to their fascinating physiochemical properties. Rationally engineering the compositions and structures of MOFs can provide abundant opportunities for their optimization. In recent years, high-entropy materials (HEMs) have demonstrated great potential in the energy and environment fields. However, there is still no report on the development of high-entropy MOFs (HE-MOFs) for photocatalytic HER in aqueous solution. Herein, the authors report the synthesis of a novel p-type HE-MOFs single crystal (HE-MOF-SC) and the corresponding HE-MOFs nanosheets (HE-MOF-NS) capable of realizing visible-light-driven photocatalytic HER. Both HE-MOF-SC and HE-MOF-NS exhibit higher photocatalytic HER activity than all the single-metal MOFs, which are supposed to be ascribed to the interplay between the different metal nodes in the HE-MOFs that enables more efficient charge transfer. Moreover, impressively, the HE-MOF-NS demonstrates much higher photocatalytic activity than the HE-MOF-SC due to its thin thickness and enhanced surface area. At optimum conditions, the rate of H2 evolution on the HE-MOF-NS is ≈13.24 mmol h-1 g-1, which is among the highest values reported for water-stable MOF photocatalysts. This work highlights the importance of developing advanced high-entropy materials toward enhanced photocatalysis.

2.
Huan Jing Ke Xue ; 45(5): 2913-2925, 2024 May 08.
Artigo em Chinês | MEDLINE | ID: mdl-38629553

RESUMO

In this study, a Meta-analysis was used to investigate the pollution status of eight farmland soil heavy metal elements (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) in China. Meanwhile, their spatiotemporal changes and differences between different types of cultivated land were explored. The research data were chosen from 449 relevant literature data collected by CNKI and Web of Science from 2005 to 2021, and the Meta-analysis used a weighted method based on "sampling numbers", "study area", and "standard deviation". The results showed that the national average values of the eight heavy metal elements in Chinese farmland soil were ω(As)11.00 mg·kg-1, ω(Cd)0.350 2 mg·kg-1, ω(Cr)62.91 mg·kg-1, ω(Cu)28.87 mg·kg-1, ω(Hg)0.135 1 mg·kg-1, ω(Ni)28.91 mg·kg-1, ω(Pb)34.67 mg·kg-1,and ω(Zn)90.24 mg·kg-1. Compared with their background values, all elements except As accumulated to some extent, and Cd and Hg accumulated the most, exceeding their background values by 177.9% and 340.3%, respectively. The research results indicated that Cd and Hg were the main pollution elements in farmland soil in China, and their accumulation was mainly influenced by human activities. In terms of their temporal and spatial changes, the Yunnan-Guizhou Plateau and the eastern coast were the most concentrated areas of pollution cases, and the pollution center shifted from the middle reaches of the Yangtze River to the southwest over time. The accumulation of heavy metals in farmland soil was affected by crop planting types, and the accumulation of heavy metals in vegetable and paddy soil was significantly greater than that in other cultivated land types.


Assuntos
Mercúrio , Metais Pesados , Poluentes do Solo , Humanos , Solo , Fazendas , China , Cádmio , Chumbo , Monitoramento Ambiental/métodos , Medição de Risco , Poluentes do Solo/análise , Metais Pesados/análise
3.
Neoplasma ; 70(3): 443-450, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37498067

RESUMO

The 5-year survival rate for patients with lung cancer, the world's second most frequent malignant tumor, is less than 20%, and its prognosis cannot be clearly predicted. Our aim was to analyze the epidermal growth factor receptor (EGFR) rs763317 (G>A) single nucleotide polymorphism and its association with prognosis in Chinese Han lung cancer patients. 839 patients with primary lung cancer were recruited, and genomic DNA was extracted and genotyped by SNPscan. Kaplan-Meier technique and multivariate Cox proportional hazards model were used to analyze the association between prognosis and EGFR polymorphism rs763317. A significant association after stratification by age, significantly increased lung cancer risk was associated with the AA homozygous genotype of rs763317 (adjusted hazard ratio = 2.53, 95% CI: 1.31-4.88, p=0.005), and conferred a poor survival for lung cancer patients (MST: median survival time: 13.6 months) compared with GG genotype (MST: 41.5 months), and in the recessive model AA genotype (AA vs. GG + GA; adjusted hazard ratio = 2.57, 95% CI: 1.34-4.93, p=0.004) who were young (<60 years) had a significantly increased risk of death. The EGFR polymorphism rs763617 might serve as a significant genetic marker for predicting the prognosis of lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , População do Leste Asiático , Receptores ErbB/genética , Predisposição Genética para Doença , Genótipo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Polimorfismo de Nucleotídeo Único , Prognóstico
4.
Front Chem ; 11: 1189450, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37090245

RESUMO

Ruthenium (Ru) has been considered a promising electrocatalyst for electrochemical hydrogen evolution reaction (HER) while its performance is limited due to the problems of particle aggregation and competitive adsorption of the reaction intermediates. Herein, we reported the synthesis of a zinc (Zn) modified Ru nanocluster electrocatalyst anchored on multiwalled carbon nanotubes (Ru-Zn/MWCNTs). The Ru-Zn catalysts were found to be highly dispersed on the MWCNTs substrate. Moreover, the Ru-Zn/MWCNTs exhibited low overpotentials of 26 and 119 mV for achieving current intensities of 10 and 100 mA cm-2 under alkaline conditions, respectively, surpassing Ru/MWCNTs with the same Ru loading and the commercial 5 wt% Pt/C (47 and 270 mV). Moreover, the Ru-Zn/MWCNTs showed greatly enhanced stability compared to Ru/MWCNTs with no significant decay after 10,000 cycles of CV sweeps and long-term operation for 90 h. The incorporation of Zn species was found to modify the electronic structure of the Ru active species and thus modulate the adsorption energy of the Had and OHad intermediates, which could be the main reason for the enhanced HER performance. This study provides a strategy to develop efficient and stable electrocatalysts towards the clean energy conversion field.

6.
Small ; 18(4): e2105544, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34841659

RESUMO

The practical deployment of promising NiFe-based oxygen evolution reaction (OER) electrocatalysts is heavily limited due to the constrain in both stability and activity under industrial conditions. Herein, a 3D free-standing NiFe(oxy)hydroxide-based electrode with Schottky junction is constructed, in which NiFe(oxy)hydroxide (NiFe(OH)x ) nanosheets are chemically assembled on the top of metal-like Ni3 S2 scaffold that are in situ formed on commercial Ni mesh. Such an assembly enhances the binding strength of each components, promotes the charge transfer across the interfaces, and modulates the electronic and nanostructural features of NiFe(OH)x . Consequently, the electrode delivers current densities of as high as 500 and 1000 mA cm-2 for OER at overpotentials of only 248 and 270 mV with long-term stability in 1 m KOH. When it was paired with a NiMo hydrogen evolution cathode in a practical two-electrode system, a current density of 1000 mA cm-2 is achieved at a low cell voltage of ≈1.61 V at 80 °C in 30% KOH without losing performance for at least 1500 h. This is the best performance reported thus far for alkaline water electrolysis under industrial conditions, demonstrating its great potential for practical applications.

7.
J Phys Chem Lett ; 12(15): 3698-3704, 2021 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-33830780

RESUMO

Defects are ubiquitous in semiconductors and critical to photo(electro)chemical performance, but the change of defect properties under light irradiation remains poorly understood. Herein, we studied defect change properties of Ta3N5 with transient absorption (TA) spectroscopy. A broad transient absorption (>650 nm) was observed and attributed to trapped electrons in oxygen impurities (substitution oxygen at nitrogen sites, ON), and two bleach signals at 510 and 580 nm were obtained and ascribed to free holes of Ta3N5. The charge recombination between the trapped electrons and the free holes is sensitively related to ON defects. The trap-detrapping recombination is retarded by increase of excitation intensity, which is contrary to the normal dependence of charge dynamics on excitation intensity. This abnormal dependence indicates that shallow ON• (singly positive charge states) defects of Ta3N5 transform to deeper ON× (neutral charge states) defects under strong light irradiation. The defect transformation results in long-lived free holes in Ta3N5 for photo(electro)catalysis.

8.
J Back Musculoskelet Rehabil ; 34(4): 565-572, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33554887

RESUMO

BACKGROUND: Persisting shoulder stiffness adversely affects quality of life by causing pain and motion restrictions especially in patients with diabetes. OBJECTIVE: The aim of this study was to evaluate the outcomes of arthroscopic capsular release in patients with idiopathic shoulder stiffness. METHOD: A literature search was conducted in electronic databases and studies were selected by following precise eligibility criteria. Random-effects meta-analyses were performed to estimate the changes at latest follow-up in scores of the Constant, American Shoulder and Elbow Surgeons (ASES), and University of California at Los Angelis (UCLA) scales, Visual Analogue Scale (VAS), and shoulder range of motion. RESULTS: Nineteen studies were included. The follow-up duration was 42 months [95% confidence interval (CI): 32, 51]. Improvements in scores of the Constant, ASES, UCLA scales, and VAS were 48.3 [95% CI: 38.0, 58.6], 44.6 [95% CI: 24.6, 64.6], 19.3 [95% CI: 16.6, 22.0], and -6.1 [95% CI: -6.9, -5.4] respectively (P< 0.05 all). Improvements in the shoulder range of motion were: abduction 82.0 [95% CI: 65.0, 98.9]; forward flexion 75.9 [95% CI: 59.7, 92.1]; external rotation 43.2 [95% CI: 37.5, 49.0]; and internal rotation 25.4 [95% CI: 15.2, 35.5] degrees; P< 0.05 all). CONCLUSION: Arthroscopic capsular release effectively improves shoulder function in patients with idiopathic shoulder stiffness.


Assuntos
Liberação da Cápsula Articular , Artropatias/cirurgia , Articulação do Ombro/cirurgia , Artroscopia , Humanos , Medição da Dor , Amplitude de Movimento Articular , Rotação , Ombro , Resultado do Tratamento , Escala Visual Analógica
9.
Angew Chem Int Ed Engl ; 60(13): 7376-7381, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33590614

RESUMO

Three-dimensional (3D) organic-inorganic hybrid perovskites have demonstrated excellent capability in solar fuel production, while the two-dimensional (2D) counterparts are generally considered inferior candidates due to the high exciton binding energy and weak light absorption. Herein, contrary to our common understanding, we find that 2D perovskites can perform photocatalytic H2 production from HI splitting more efficiently than their 3D counterparts. We observed sharp difference between 2D perovskites crystals with organic phenylalkylammonium cations of different lengths and the 3D counterparts in their stabilization behavior in aqueous solution. Moreover, we show that the organic cations length of the 2D perovskites affects the nanostructures, optoelectronic properties, and the charge transfer process significantly, which determines the photocatalytic activity of the 2D perovskites. Among the 2D perovskites under investigation, phenylmethylammonium lead iodide with the shortest organic cations achieved the best solar-to-chemical conversion efficiency of ca. 1.57 %, which is the highest value ever reported for hybrid perovskites.

10.
Cancer Med ; 9(14): 5086-5094, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32459060

RESUMO

The objective of this study was to predict the value of lymphocyte subsets in cancer progression. Peripheral blood was obtained from 327 untreated patients with cancer and 158 healthy volunteers. Levels of lymphocyte subsets were determined by flow cytometry. There were decreased levels of natural killer (NK) cells, CD8+ T cells, and naïve CD4+ /CD4+ T cells in untreated patients with cancer compared to those in healthy controls. Inversely, there were elevated levels of the following T-cell percentages in cancer patients compared to those in healthy controls: memory CD4+ /CD4+ , CD8+ T cells, HLA-DR/CD8+ , CD8+ CD38+ /CD8+ , and CD4+ /CD8+ . In addition, there are a decreasing trend in terms of CD4+ T-cell counts and an increase CD8+ HLA-DR/CD8+ T-cell and CD8+ CD38+ /CD8+ T-cell percentages in the advanced stage. An increasing trend with advanced tumor stage and the percentages of CD8+ HLA-DR/CD8+ T cells and CD8+ CD38+ /CD8+ T cells was shown in this study. There are a negative correlation for CD4+ T-cell counts and positive correlation for percentages of CD8+ HLA-DR/CD8+ T cell and CD8+ CD38+ /CD8+ T cells with the lymph node metastasis. In the presence of distant metastatic spread, we observed higher NK-cell counts, CD8+ HLA-DR/CD8+ T-cell percentages, CD8+ CD38+ /CD8+ T-cell percentages, as well as lower CD4+ T-cell counts than those in the absence of distant metastases spread. Abnormal levels of NK cell, CD8+ T cells, memory CD4+ /CD4+ , naïve CD4+ / CD4+ , CD8+ HLA-DR/CD8+ , CD8+ CD38+ /CD8+ , and CD4+ /CD8+ can be a potential blood biomarkers of cancer development. CD4+ T-cell counts and percentages of CD8+ HLA-DR/ CD8+ and CD8+ CD38+ / CD8+ can predict the cancer progression.


Assuntos
Biomarcadores Tumorais/metabolismo , Contagem de Linfócitos/métodos , Linfócitos/metabolismo , Neoplasias/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Microambiente Tumoral , Adulto Jovem
11.
Angew Chem Int Ed Engl ; 59(31): 12909-12916, 2020 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-32249516

RESUMO

Photo-thermo catalysis, which integrates photocatalysis on semiconductors with thermocatalysis on supported nonplasmonic metals, has emerged as an attractive approach to improve catalytic performance. However, an understanding of the mechanisms in operation is missing from both the thermo- and photocatalytic perspectives. Deep insights into photo-thermo catalysis are achieved via the catalytic oxidation of propane (C3 H8 ) over a Pt/TiO2 -WO3 catalyst that severely suffers from oxygen poisoning at high O2 /C3 H8 ratios. After introducing UV/Vis light, the reaction temperature required to achieve 70 % conversion of C3 H8 lowers to a record-breaking 90 °C from 324 °C and the apparent activation energy drops from 130 kJ mol-1 to 11 kJ mol-1 . Furthermore, the reaction order of O2 is -1.4 in dark but reverses to 0.1 under light, thereby suppressing oxygen poisoning of the Pt catalyst. An underlying mechanism is proposed based on direct evidence of the in-situ-captured reaction intermediates.

12.
Sci Rep ; 9(1): 19408, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31857646

RESUMO

Nitrogen (N), phosphorus (P), and potassium (K) exert various effects on adzuki bean yields. Our research was conducted in a semi-arid area, and four test sites were established in environments that have chernozem or sandy loam soils. During a five-year period, the effects of N, P, and K fertilizers on yield were comprehensively investigated in field trials (2014-2016) and for model-implementation trials (2017-2018), with models established prior to the latter. In the field trials, 23 treatments comprising different N, P, and K combinations significantly affected both yield and yield components, and regression analysis indicated that the experimental results were suitable for model establishment. The model subsequently demonstrated that the yield and the yield components were more sensitive to N and K fertilizer than to P fertilizer. Moreover, the yield and yield components increased. These yield increases were intense in response to the 0.5 to 1.34 levels in terms of the single effects; interaction effects; and the effects of combinations of N, P, and K fertilizers. Moreover, the effects of combinations of N, P, and K fertilizers were more significant on yield than were the single or interaction effects of N, P, and K fertilizers. The optimal fertilizer combination that resulted in high yields (≥1941.53 kg ha-1) comprised 57.23-68.43 kg ha-1 N, 36.04-47.32 kg ha-1 P2O5 and 50.29-61.27 kg ha-1 K2O. The fertilizer combination that resulted in the maximum yield was 62.98 kg ha-1 N, 47.04 kg ha-1 P2O5 and 59.95 kg ha-1 K2O (N:P2O5:K2O = 1:0.75:0.95), which produced the model-expected yield in trials at multiple sites. An economical fertilizer combination was determined on the basis of the best fertilizer measures in consideration of the cost of fertilizer and seed; this combination achieved yields of 2236.17 kg ha-1, the profit was 15,653.16 Yuan ha-1, and the corresponding rates were 57.60 kg ha-1 N, 47.03 kg ha-1 P2O5, and 31.64 kg ha-1 K2O (N:P2O5:K2O = 1:0.82:0.55).


Assuntos
Clima Desértico , Fertilizantes , Nitrogênio/farmacologia , Fósforo/farmacologia , Potássio/farmacologia , Vigna/crescimento & desenvolvimento , China , Fertilizantes/economia , Modelos Teóricos , Análise de Regressão , Vigna/efeitos dos fármacos
13.
Materials (Basel) ; 11(9)2018 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-30135388

RESUMO

Lignin can be a candidate as a charring agent applied in halogen-free flame retardant polymers, and incorporation of silicon and nitrogen elements in lignin can benefit to enhancing its thermal stability and charring ability. In the present work, wheat straw alkali lignin (Lig) was modified to incorporate silicon and nitrogen elements by γ-divinyl-3-aminopropyltriethoxysilane, and the modified lignin (CLig) was combined with ammonium polyphosphate (APP) as intumescent flame retardant to be applied in poly(Lactic acid) (PLA). The flame retardancy, combustion behavior and thermal stability of PLA composites were studied by the limited oxygen index (LOI), vertical burning testing (UL-94), cone calorimetry testing (CCT) and thermogravimetric analysis (TGA), respectively. The results showed a significant synergistic effect between CLig and APP in flame retarded PLA (PLA/APP/CLig) occured, and the PLA/APP/CLig had better flame retardancy. CCT data analysis revealed that CLig and APP largely reduced the peak heat release rate (PHRR) and total heat release rate (THR) of PLA, indicating their effectiveness in decreasing the combustion of PLA. TGA results exhibited that APP and CLig improved the thermal stability of PLA at high temperature. The analysis of morphology and structure of residual char indicated that a continuous, compact and intumescent char layer on the material surface formed during firing, and had higher graphitization degree. Mechanical properties data showed that PLA/APP/CLig had higher tensile strength as well as elongation at break.

14.
Angew Chem Int Ed Engl ; 57(13): 3473-3477, 2018 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-29411479

RESUMO

Carbon dioxide (CO2 ) and hydrogen sulfide (H2 S) are generally concomitant with methane (CH4 ) in natural gas and traditionally deemed useless or even harmful. Developing strategies that can simultaneously convert both CO2 and H2 S into value-added products is attractive; however it has not received enough attention. A solar-driven electrochemical process is demonstrated using graphene-encapsulated zinc oxide catalyst for CO2 reduction and graphene catalyst for H2 S oxidation mediated by EDTA-Fe2+ /EDTA-Fe3+ redox couples. The as-prepared solar-driven electrochemical system can realize the simultaneous conversion of CO2 and H2 S into carbon monoxide and elemental sulfur at near neutral conditions with high stability and selectivity. This conceptually provides an alternative avenue for the purification of natural gas with added economic and environmental benefits.

15.
ACS Appl Mater Interfaces ; 9(36): 30696-30702, 2017 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-28832111

RESUMO

Photoelectrochemical water splitting provides an attractive way to store solar energy in molecular hydrogen as a kind of sustainable fuel. To achieve high solar conversion efficiency, the most stringent criteria are effective charge separation and injection in electrodes. Herein, efficient photoelectrochemical water oxidation is realized by optimizing charge separation and surface charge transfer of GaN:ZnO photoanode. The charge separation can be greatly improved through modified moisture-assisted nitridation and HCl acid treatment, by which the interfaces in GaN:ZnO solid solution particles are optimized and recombination centers existing at the interfaces are depressed in GaN:ZnO photoanode. Moreover, a multimetal phosphide of NiCoFeP was employed as water oxidation cocatalyst to improve the charge injection at the photoanode/electrolyte interface. Consequently, it significantly decreases the overpotential and brings the photocurrent to a benchmark of 3.9 mA cm-2 at 1.23 V vs RHE and a solar conversion efficiency over 1% was obtained.

16.
Angew Chem Int Ed Engl ; 55(32): 9229-33, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27345863

RESUMO

Integrating natural and artificial photosynthetic platforms is an important approach to developing solar-driven hybrid systems with exceptional function over the individual components. A natural-artificial photosynthetic hybrid platform is formed by wiring photosystem II (PSII) and a platinum-decorated silicon photoelectrochemical (PEC) cell in a tandem manner based on a photocatalytic-PEC Z-scheme design. Although the individual components cannot achieve overall water splitting, the hybrid platform demonstrated the capability of unassisted solar-driven overall water splitting. Moreover, H2 and O2 evolution can be separated in this system, which is ascribed to the functionality afforded by the unconventional Z-scheme design. Furthermore, the tandem configuration and the spatial separation between PSII and artificial components provide more opportunities to develop efficient natural-artificial hybrid photosynthesis systems.


Assuntos
Técnicas Eletroquímicas , Complexo de Proteína do Fotossistema II/isolamento & purificação , Silício/isolamento & purificação , Água/metabolismo , Hidrogênio/química , Hidrogênio/isolamento & purificação , Hidrogênio/metabolismo , Oxigênio/química , Oxigênio/isolamento & purificação , Oxigênio/metabolismo , Processos Fotoquímicos , Complexo de Proteína do Fotossistema II/metabolismo , Platina/química , Platina/metabolismo , Silício/química , Silício/metabolismo , Água/química
17.
Genome ; 59(10): 827-839, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27327818

RESUMO

Urbanization requires the conversion of natural land cover to cover with human-constructed elements and is considered a major threat to biodiversity. Bee populations, globally, are under threat; however, the effect of rapid urban expansion in Southeast Asia on bee diversity has not been investigated. Given the pressing issues of bee conservation and urbanization in Southeast Asia, coupled with complex factors surrounding human-bee coexistence, we investigated bee diversity and human perceptions of bees in four megacities. We sampled bees and conducted questionnaires at three different site types in each megacity: a botanical garden, central business district, and peripheral suburban areas. Overall, the mean species richness and abundance of bees were significantly higher in peripheral suburban areas than central business districts; however, there were no significant differences in the mean species richness and abundance between botanical gardens and peripheral suburban areas or botanical gardens and central business districts. Urban residents were unlikely to have seen bees but agreed that bees have a right to exist in their natural environment. Residents who did notice and interact with bees, even though being stung, were more likely to have positive opinions towards the presence of bees in cities.


Assuntos
Abelhas , Biodiversidade , Cidades , Percepção , Animais , Sudeste Asiático , Abelhas/classificação , Abelhas/genética , Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons/genética , Geografia , Humanos , Dinâmica Populacional , Opinião Pública , Inquéritos e Questionários
18.
Nat Commun ; 7: 11474, 2016 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-27142885

RESUMO

Solar rechargeable flow cells (SRFCs) provide an attractive approach for in situ capture and storage of intermittent solar energy via photoelectrochemical regeneration of discharged redox species for electricity generation. However, overall SFRC performance is restricted by inefficient photoelectrochemical reactions. Here we report an efficient SRFC based on a dual-silicon photoelectrochemical cell and a quinone/bromine redox flow battery for in situ solar energy conversion and storage. Using narrow bandgap silicon for efficient photon collection and fast redox couples for rapid interface charge injection, our device shows an optimal solar-to-chemical conversion efficiency of ∼5.9% and an overall photon-chemical-electricity energy conversion efficiency of ∼3.2%, which, to our knowledge, outperforms previously reported SRFCs. The proposed SRFC can be self-photocharged to 0.8 V and delivers a discharge capacity of 730 mAh l(-1). Our work may guide future designs for highly efficient solar rechargeable devices.

19.
Chem Sci ; 7(9): 6076-6082, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30034748

RESUMO

New insight into junction-based designs for efficient charge separation is vitally important for current solar energy conversion research. Herein, an anatase-rutile phase junction is elaborately introduced into TiO2 films by rapid thermal annealing treatment and the roles of phase junction on charge separation and transfer are studied in detail. A combined study of transient absorption spectroscopy, electrochemical and photoelectrochemical (PEC) measurements reveals that appropriate phase alignment is essential for unidirectional charge transfer, and a junction interface with minimized trap states is crucial to liberate the charge separation potential of the phase junction. By tailored control of phase alignment and interface structure, an optimized TiO2 film with an appropriately introduced phase junction shows superior performance in charge separation and transfer, hence achieving ca. 3 and 9 times photocurrent density enhancement compared to pristine anatase and rutile phase TiO2 electrodes, respectively. This work demonstrates the great potential of phase junctions for efficient charge separation and transfer in solar energy conversion applications.

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