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1.
Adv Sci (Weinh) ; : e2401730, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696659

RESUMO

Sodium ion batteries (SIBs) are considered as the ideal candidates for the next generation of electrochemical energy storage devices. The major challenges of anode lie in poor cycling stability and the sluggish kinetics attributed to the inherent large Na+ size. In this work, Bi nanosphere encapsulated in N-doped carbon nanowires (Bi@N-C) is assembled by facile electrospinning and carbonization. N-doped carbon mitigates the structure stress/strain during alloying/dealloying, optimizes the ionic/electronic diffusion, and provides fast electron transfer and structural stability. Due to the excellent structure, Bi@N-C shows excellent Na storage performance in SIBs in terms of good cycling stability and rate capacity in half cells and full cells. The fundamental mechanism of the outstanding electrochemical performance of Bi@N-C has been demonstrated through synchrotron in-situ XRD, atomic force microscopy, ex-situ scanning electron microscopy (SEM) and density functional theory (DFT) calculation. Importantly, a deeper understanding of the underlying reasons of the performance improvement is elucidated, which is vital for providing the theoretical basis for application of SIBs.

2.
Dalton Trans ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38738949

RESUMO

Catalysts made of CuO/Bi2O3 nanoparticles supported on g-C3N4 were synthesized using a MOF-derived strategy. The activation of CuO to CuCCCu species and stabilization of the catalyst were facilitated by the synergistic effect of the CuO/C3N4 interface and CuO nanoparticles, resulting in enhanced catalytic efficacy in the ethynylation of formaldehyde.

3.
Radiol Med ; 129(4): 653-664, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38512609

RESUMO

PURPOSE: The objective of this study was to develop and validate a novel prognostic nomogram to evaluate the survival benefit of hepatocellular carcinoma (HCC) patients receiving postoperative adjuvant transarterial chemoembolization (PA-TACE). MATERIALS AND METHODS: Clinical data of HCC patients who underwent hepatectomy at four medical centers were retrospectively analyzed, including those who received PA-TACE and those who did not. These two categories of patients were randomly allocated to the development and validation cohorts in a 7:3 ratio. RESULTS: A total of 1505 HCC patients who underwent hepatectomy were included in this study, comprising 723 patients who did not receive PA-TACE and 782 patients who received PA-TACE. Among them, patients who received PA-TACE experienced more adverse events, although these events were mild and manageable (Grade 1-2, all p < 0.05). Nomograms were constructed and validated for patients with and without PA-TACE using independent predictors that influenced disease-free survival (DFS) and overall survival (OS). These two nomograms had C-indices greater than 0.800 in the development cohort and exhibited good calibration and discrimination ability compared to six conventional HCC staging systems. Patients in the intermediate-to-high-risk group in the nomogram who received PA-TACE had higher DFS and OS (all p < 0.05). In addition, tumor recurrence was significantly controlled in the intermediate-to-high-risk group of patients who received PA-TACE, while there was no significant difference in the low-risk group of patients who received PA-TACE. CONCLUSION: The nomograms were developed and validated based on large-scale clinical data and can serve as online decision-making tools to predict survival benefits from PA-TACE in different subgroups of patients.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Nomogramas , Estudos Retrospectivos , Recidiva Local de Neoplasia/patologia , Prognóstico , Hepatectomia
4.
Clin Med Insights Oncol ; 18: 11795549231225409, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38332774

RESUMO

Background: Hepatocellular carcinoma (HCC) patients have a poor prognosis after radio-frequency ablation (RFA), and investigating the risk factors affecting RFA and establishing predictive models are important for improving the prognosis of HCC patients. Methods: Patients with HCC undergoing RFA in Shenzhen People's Hospital between January 2011 and December 2021 were included in this study. Using the screened independent influences on recurrence and survival, predictive models were constructed and validated, and the predictive models were then used to classify patients into different risk categories and assess the prognosis of different categories. Results: Cox regression model indicated that cirrhosis (hazard ratio [HR] = 1.65), alpha-fetoprotein (AFP) ⩾400 ng/mL (HR = 2.03), tumor number (multiple) (HR = 2.11), tumor diameter ⩾20 mm (HR = 2.30), and platelets (PLT) ⩾ 244 (109/L) (HR = 2.37) were independent influences for recurrence of patients after RFA. On the contrary, AFP ⩾400 ng/mL (HR = 2.48), tumor number (multiple) (HR = 2.52), tumor diameter ⩾20 mm (HR = 2.25), PLT ⩾244 (109/L) (HR = 2.36), and hemoglobin (HGB) ⩾120 (g/L) (HR = 0.34) were regarded as independent influences for survival. The concordance index (C-index) of the nomograms for predicting disease-free survival (DFS) and overall survival (OS) was 0.727 (95% confidence interval [CI] = 0.770-0.684) and 0.770 (95% CI = 0.821-7.190), respectively. The prognostic performance of the nomograms was significantly better than other staging systems by analysis of the time-dependent C-index and decision curves. Each patient was scored using nomograms and influencing factors, and patients were categorized into low-, intermediate-, and high-risk groups based on their scores. In the Kaplan-Meier survival curve, DFS and OS were significantly better in the low-risk group than in the intermediate- and high-risk groups. Conclusions: The 2 prediction models created in this work can effectively predict the recurrence and survival rates of HCC patients following RFA.

5.
J Cancer ; 15(1): 68-78, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38164269

RESUMO

Background: The presence of microvascular invasion (MVI) significantly worsens the surgical outcome of hepatocellular carcinoma (HCC). The purpose of this research was to investigate the survival benefit of adjuvant transarterial chemoembolization (TACE) in patients with MVI after hepatectomy. Methods: A retrospective analysis was conducted on 1372 HCC patients who underwent curative liver resection in four medical institutions. In order to minimize confounding factors and selection bias between groups, Propensity Score Matching (PSM) (1:1) was performed to ensure balanced clinical characteristics. Results: A total of 1056 patients were enrolled after PSM, including 672 patients with MVI and 384 patients without MVI. Adjuvant TACE improves DFS (Median, 36 months vs 14 months, p < 0.001) and OS (Median, NA vs 32 months, p < 0.001) in patients harboring MVI, but not in those (all p > 0.05) lacking MVI. In different different CNLC stages, adjuvant TACE improved DFS (CNLC stage I, Median, 37 vs 15 months; CNLC stage II, Median, 25 vs 11 months, p < 0.001) and OS (CNLC stage I, Median, NA vs 32 months, p < 0.001; CNLC stage II, Median, NA vs 26 months, p = 0.002) in patients who carried MVI, but not in those (CNLC stage I-II, all p > 0.05) who lacked MVI. Conclusions: Adjuvant TACE may be a potentially effective treatment option for improving survival outcomes in early-HCC patients harboring MVI, but not in those lacking MVI.

6.
Inorg Chem ; 63(1): 881-890, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38130105

RESUMO

CO2 methanation has attracted considerable attention as a promising strategy for recycling CO2 and generating valuable methane. This study presents a niobium-doped CeO2-supported Ni catalyst (Ni/NbCe), which demonstrates remarkable performance in terms of CO2 conversion and CH4 selectivity, even when operating at a low temperature of 250 °C. Structural analysis reveals the incorporation of Nb species into the CeO2 lattice, resulting in the formation of a Nb-Ce-O solid solution. Compared with the Ni/CeO2 catalyst, this solid solution demonstrates an improved spatial distribution. To comprehend the impact of the Nb-Ce-O solid solution on refining the electronic properties of the Ni-Ce interfacial sites, facilitating H2 activation, and accelerating the hydrogenation of CO2* into HCOO*, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis and density functional theory (DFT) calculations were conducted. These investigations shed light on the mechanism through which the activity of CO2 methanation is enhanced, which differs from the commonly observed CO* pathway triggered by oxygen vacancies (OV). Consequently, this study provides a comprehensive understanding of the intricate interplay between the electronic properties of the catalyst's active sites and the reaction pathway in CO2 methanation over Ni-based catalysts.

7.
Chem Commun (Camb) ; 60(6): 750-753, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38116817

RESUMO

Zn anodes of aqueous batteries face severe challenges from side reactions and dendrite growth. Here, triethanolamine (TEOA) is developed as an electrolyte additive to address these challenges. It enhances the exposure of Zn(002) and diminishes the change in pH. Therefore, the electrolyte containing TEOA shows improved electrochemical performance.

8.
J Natl Compr Canc Netw ; 22(1D): e237069, 2023 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-38118280

RESUMO

BACKGROUND: Early relapse after hepatectomy presents a significant challenge in the treatment of hepatocellular carcinoma (HCC). The aim of this study was to construct and validate a novel nomogram model for predicting early relapse and survival after hepatectomy for HCC. PATIENTS AND METHODS: We conducted a large-scale, multicenter retrospective analysis of 1,505 patients with surgically treated HCC from 4 medical centers. All patients were randomly divided into either the training cohort (n=1,053) or the validation cohort (n=452) in a 7:3 ratio. A machine learning-based nomogram model for prediction of HCC was established by integrating multiple risk factors that influence early relapse and survival, which were identified from preoperative clinical data and postoperative pathologic characteristics of the patients. RESULTS: The median time to early relapse was 7 months, whereas the median time from early relapse to death was only 19 months. The concordance indexes of the postoperative nomogram for predicting disease-free survival and overall survival were 0.741 and 0.739, respectively, with well-calibrated curves demonstrating good consistency between predicted and observed outcomes. Moreover, the accuracy and predictive performance of the postoperative nomograms were significantly superior to those of the preoperative nomogram and the other 7 HCC staging systems. The patients in the intermediate- and high-risk groups of the model had significantly higher probabilities of early and critical recurrence (P<.001), whereas those in the low-risk group had higher probabilities of late and local recurrence (P<.001). CONCLUSIONS: This postoperative nomogram model can better predict early recurrence and survival and can serve as a useful tool to guide clinical treatment decisions for patients with HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Nomogramas , Estudos Retrospectivos , Recidiva Local de Neoplasia/epidemiologia , Recidiva Local de Neoplasia/patologia , Fatores de Risco , Recidiva , Prognóstico
9.
Small Methods ; : e2301372, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38098164

RESUMO

Sodium-ion batteries (SIBs) are investigated as promising alternatives to lithium-ion batteries (LIBs) on account of the economical abundance and reliable availability of sodium, as well as its analogous chemical properties compared to lithium. Nevertheless, the performance of SIBs is severely restricted by the availability of satisfactory cathode nanomaterials with stable frameworks to accommodate the transportation of large-sized Na+ ions. These challenges can be effectively resolved when exploiting Prussian blue (PB) and its analogs (PBAs) as SIB cathodes. This is mainly because PB and PBAs have 3D open frameworks with large interstitial space, which are more favorable for fast insertion/extraction of Na+ ions during the charging/discharging process, thus enabling the improvement of integrated performance in SIB systems. This overview offers a comprehensive summarization of recent advancements in the electrochemical performance of PB and PBAs when employing them as cathodes in SIBs. For better understanding, the fabrication strategy, structural characterization, and electrochemical performance exposition are systematically organized and explained according to tuning PB and metal-based PBAs. Additionally, the current trajectories and prospective future directions pertaining to the utilization of PB and PBA cathodes in the SIB system are thoroughly examined and deliberated upon.

10.
BMC Cancer ; 23(1): 325, 2023 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-37029339

RESUMO

BACKGROUND: The survival benefit of adjuvant transarterial chemoembolization (TACE) in patients with hepatectomy for hepatocellular carcinoma (HCC) after hepatectomy remains controversial. We aimed to investigate the survival efficacy of adjuvant TACE after hepatectomy for HCC. METHODS: 1491 patients with HCC who underwent hepatectomy between January 2018 and September 2021 at four medical centers in China were retrospectively analyzed, including 782 patients who received adjuvant TACE and 709 patients who did not receive adjuvant TACE. Propensity score matching (PSM) (1:1) was performed to minimize selection bias, which balanced the clinical characteristics of the two groups. RESULTS: A total of 1254 patients were enrolled after PSM, including 627 patients who received adjuvant TACE and 627 patients who did not receive adjuvant TACE. Patients who received adjuvant TACE had higher disease-free survival (DFS, 1- ,2-, and 3-year: 78%-68%-62% vs. 69%-57%-50%, p < 0.001) and overall survival (OS, 1- ,2-, and 3-year: 96%-88%-80% vs. 90%-77%-66%, p < 0.001) than those who did not receive adjuvant TACE (Median DFS was 39 months). Among the different levels of risk factors affecting prognosis [AFP, Lymphocyte-to-monocyte ratio, Maximum tumor diameter, Number of tumors, Child-Pugh classification, Liver cirrhosis, Vascular invasion (imaging), Microvascular invasion, Satellite nodules, Differentiation, Chinese liver cancer stage II-IIIa], the majority of patients who received adjuvant TACE had higher DFS or OS than those who did not receive adjuvant TACE. More patients who received adjuvant TACE accepted subsequent antitumor therapy such as liver transplantation, re-hepatectomy and local ablation after tumor recurrence, while more patients who did not receive adjuvant TACE accepted subsequent antitumor therapy with TACE after tumor recurrence (All p < 0.05). CONCLUSIONS: Adjuvant TACE may be a potential way to monitor early tumor recurrence and improve postoperative survival in patients with HCC.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Hepatectomia , Recidiva Local de Neoplasia/patologia , Pontuação de Propensão , Estudos Retrospectivos , Quimioembolização Terapêutica/métodos , Prognóstico , Adjuvantes Imunológicos , Resultado do Tratamento
11.
United European Gastroenterol J ; 11(2): 228-241, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36905230

RESUMO

BACKGROUND: We aimed to investigate the efficacy of postoperative adjuvant transarterial chemoembolisation (PA-TACE) in patients with hepatocellular carcinoma (HCC) complicated by microvascular invasion (MVI). METHODS: A retrospective analysis of 1505 patients with HCC who underwent hepatectomy at four medical centers, including 782 patients who received PA-TACE and 723 patients who did not receive adjuvant PA-TACE, has been conducted. Propensity score matching (PSM) (1:1) was performed on the data to minimise selection bias, which resulted in a balanced clinical profile between groups. RESULTS: After PSM, 620 patients who received PA-TACE and 620 patients who did not receive PA-TACE were included. Disease-free survival (DFS, 1-, 2-, and 3-year: 88%-68%-61% vs. 70%-58%-51%, p < 0.001) and overall survival (OS, 1-, 2-, and 3-year: 96%-89%-82% vs. 89%-77%-67%, p < 0.001) were significantly higher in patients who received PA-TACE than in those who did not. Patients with MVI who received PA-TACE had significantly higher DFS (1-, 2-, and 3-year: 68%-57%-48% vs. 46%-31%-27%, p < 0.001) and OS (1-, 2-, and 3-year: 96%-84%-77% vs. 79%-58%-40%, p < 0.001) than those who did not receive PA-TACE. Among the six different liver cancer stages, MVI-negative patients did not have significant survival outcomes from PA-TACE (p > 0.05), whereas MVI-positive patients achieved higher DFS and OS from it (p < 0.05). Liver dysfunction, fever, and nausea/vomiting were the most common adverse events in patients receiving PA-TACE. There was no significant difference in grade 3 or 4 adverse events between the groups (p > 0.05). CONCLUSIONS: Postoperative adjuvant transarterial chemoembolisation has a good safety profile and may be a potentially beneficial treatment modality for survival outcomes in patients with HCC, especially those with concomitant MVI.


Assuntos
Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/cirurgia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/patologia , Estudos Retrospectivos , Resultado do Tratamento , Quimioembolização Terapêutica/efeitos adversos , Quimioembolização Terapêutica/métodos
12.
Immunol Lett ; 253: 1-7, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36460232

RESUMO

BACKGROUND: Preeclampsia is a major cause of increased maternal and fetal morbidity and mortality, which is closely related to the abnormal maternal immune response. The skew of decidual macrophage polarization toward M1 phenotype has been proved to promote the pathogenesis of preeclampsia. However, it's not easy to monitor the change of decidual macrophage subtypes. The current study aims to examine the distribution of different circulating monocyte subtypes and analyze whether certain monocyte subtypes act as potential clinical indicators for preeclampsia. METHODS: A total of 50 pregnant women [mild preeclampsia (n = 20); severe preeclampsia (n = 15); healthy pregnancy (n = 15)] and 15 healthy donors were included in the study. Medical information such as BMI, blood pressure, ALT, creatinine, thrombocyte, etc., were recorded. The frequency of different monocyte subtypes in venous blood were measured by flow cytometry. Serum level of IL-6 was detected using Roche-Hitachi cobas 8000. Serum concentration of inflammatory cytokines (IL-1ß, IL-4, IL-10 and TNF-α) were measured by ELISA. RESULTS: A circulating monocyte subset with both M1 and M2 markers (CD14+CD16+CD163+) was found to occupy an obvious higher proportion in the preeclampsia group than in the normal pregnancy group. The ratio of CD206+/CD206- M2-like monocytes was also increased in the preeclampsia group, and meanwhile, it had statistic difference between the mild- and the severe-preeclampsia group. Furthermore, the serum levels of IL-1ß and TNF-α were positively correlated with the frequency of CD14+CD16+CD163+ intermediate monocytes in the preeclampsia group. CONCLUSIONS: The increased proportion of CD14+C16+CD163+ circulating monocytes and the high ratio of CD206+/CD206- M2-like monocytes may act as potential clinical indicators for preeclampsia, with the superiority of convenience and dynamic monitoring.


Assuntos
Monócitos , Pré-Eclâmpsia , Feminino , Humanos , Gravidez , Receptores de Lipopolissacarídeos , Fenótipo , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/patologia , Fator de Necrose Tumoral alfa
13.
Chem Commun (Camb) ; 58(92): 12859-12862, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36317636

RESUMO

Herein, V-doped cobalt hydroxides grown on carbon cloth (V-Co(OH)2/CC) were prepared via hydrothermal method. The incorporation of V can trigger phase transition and tune the local electronic structure of Co(OH)2, thereby improving the intrinsic alkaline HER activity. We find that the V-Co(OH)2 dominated by ß-Co(OH)2 exhibits excellent HER activity with only 83 mV overpotential at a current density of 10 mA cm-2, which outperforms most reported hydroxide-based catalysts and even surpasses the commercial Pt/C at large current density (>160 mA cm-2).

14.
ACS Omega ; 7(32): 27787-27797, 2022 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-35990490

RESUMO

Aiming at the challenge that environmental protection and high-temperature fluid loss reduction performance of the traditional water-based drilling fluid treatment agent are difficult to balance, our studies added psyllium husk as a high-temperature-resistant and environmentally friendly filtrate reducer to a water-based drilling fluid. The composition, physical and chemical properties, and microstructure of psyllium husk are characterized. Then, the effects of psyllium husk after hot rolling at different temperatures on the rheological properties and fluid loss properties of bentonite-based slurry are evaluated. The results show that the psyllium husk added to the bentonite-based slurry can effectively improve the rheological properties and fluid loss properties of the bentonite-based slurry, and the temperature resistance can reach 160 °C. After hot rolling at 160 °C, adding 1 w/v % psyllium husk can reduce the API fluid loss and high-temperature and high-pressure fluid loss of the bentonite-based slurry by 76.04 and 56.91%, respectively, showing excellent fluid loss reduction performance at high temperatures. The branched structure and uronic acid of psyllium husk can inhibit the degradation of its own molecular structure to a certain extent, which is the fundamental reason why psyllium husk still has excellent fluid loss reduction performance at high temperatures. Psyllium husk is expected to replace some traditional synthetic polymers and be used in environmentally friendly high-temperature-resistant water-based drilling fluids.

15.
J Colloid Interface Sci ; 620: 77-85, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35421755

RESUMO

The incipient wetness impregnation (IWI) method is widely used in the preparation of supported transition metal catalysts for its high throughput and cost-effective synthesis, yet suffers from poor metal-support interaction, restricting its further application at an industrial scale. Herein, a universal strategy of chelation coupled impregnation (CCI) is presented. The as-prepared Ni/CeO2(CCI) showed superior catalytic performance for CO2 conversion (84.3%) and CH4 selectivity (100%) under the experimental conditions (WGHSV = 24,000 mL g-1 h-1 and H2/CO2 = 4:1) even at low temperatures (T = 275 °C). The surface characterization results confirmed that the agglomeration of metal active sites in Ni/CeO2(CCI) was restricted and more surface oxygen vacancies were generated on CeO2. Further, the in-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) analysis suggested that the surface oxygen vacancies that served as active sites could facilitate the direct dissociation of CO2 more favorably than the associative route, thus significantly promoting CO2 methanation activity.

16.
ACS Appl Mater Interfaces ; 14(10): 12551-12561, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35257574

RESUMO

Potassium-ion batteries (KIBs) are gradually being considered as an alternative for lithium-ion batteries because of their non-negligible advantages such as abundance and low expenditure of K, as well as higher electrochemical potential than another alternative─sodium-ion batteries. Nevertheless, when the electrode materials are inserted and extracted with large-sized K+ ions, the tremendous volume change will cause the collapse of the microstructures of electrodes and make the charging/discharging process irreversible, thus disapproving their extended application. In response to this, we put forward a feasible strategy to realize the in situ assembly of layered MoSe2 nanosheets onto N, P codoped hollow carbon nanospheres (MoSe2/NP-HCNSs) through thermal annealing and heteroatom doping strategies, and the resulting nanoengineered material can function well as an anode for KIBs. This cleverly designed nanostructure of MoSe2/NP-HCNS can broaden the interlayer spacing of MoSe2 to boost the efficiency of the insertion/extraction of K ions and also can accommodate large volume change-caused mechanical strain, facilitate electrolyte penetration, and prevent the aggregation of MoSe2 nanosheets. This synthetic method generates abundant defects to increase the amounts of active sites, as well as conductivity. The hierarchical nanostructure can effectively increase the proportion of pseudo-capacitance and promote interfacial electronic transfer and K+ diffusion, thus imparting great electrochemical performance. The MoSe2/NP-HCNS anode exhibits a high reversible capacity of 239.9 mA h g-1 at 0.1 A g-1 after 200 cycles and an ultralong cycling life of 161.1 mA h g-1 at 1 A g-1 for a long period of 1000 cycles. This nanoengineering method opens up new insights into the development of promising anode materials for KIBs.

17.
J Colloid Interface Sci ; 608(Pt 3): 2515-2528, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34774318

RESUMO

Heterogeneous photo-Fenton catalysts prepared by doping metal ions in g-C3N4 are promising alternatives to traditional homogeneous Fenton catalysts, but are restricted by poor mesoporous structure and agglomerate of metal species. Recently, the highly uniformly dispersed metal-N active sites in various photocatalysts have been proved to be the critical reason for their enhanced catalytic activity. In this study based on reasonable control of mesoporous structure and metal-N active sites, mesoporous Fe-g-C3N4 was synthesized using a simple one-step thermal shrinkage polymerization method using ferrous oxalate as iron source and pore-forming agent. The Fe and N elements in the triazine ring skeleton of Fe-g-C3N4 form a σ-π bond, thus the photogenerated electrons can be quickly transferred to Fe3+ to form Fe2+ under the interaction of chemical bonds, accelerating the Fenton reaction rate. Density functional theory calculations results demonstrate that the energy band structure and electron cloud density distribution of Fe-Nx active structure are better than that of routine FeOx crystal structure with metal species agglomeration. In addition, the excellent mesoporous structure of Fe-g-C3N4 creates conditions for the high exposure of Fe-Nx active sites in the photo-Fenton reaction under visible light. The as-developed Fe-g-C3N4 system shows high recyclability and excellent photo-Fenton performance for removal of typical intractable pollutants (The degradation rate of dye and tetracycline reaches 98.2% and 98.7% at 60 and 120 min, respectively). This work provides a facile and sustainable route to develop mesoporous highly-active heterogeneous Fenton-like catalysts and even further general the design of general catalyst with ideal metal-N active sites, thereby promoting a feasible and efficient wastewater remediation solution.


Assuntos
Peróxido de Hidrogênio , Luz , Catálise , Ferro , Tetraciclina
18.
Sci Total Environ ; 797: 149025, 2021 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-34303968

RESUMO

Sulfur (S) dynamics in soils formed from granite remain poorly understood despite its importance as an essential plant macronutrient and component of soil organic matter. We used stable S isotope ratios to trace the sources and biogeochemical processes of S in four forest soil profiles developed on granite under contrasting climate conditions. The soil S is derived mainly from decomposing litter; no significant geogenic contribution to its content is noted as a result of the low S concentration of the granite (~ 5 µg/g). Colder/drier climate results in high organic S retention at the surface due to weak mineralization of organic S. Although warmer/wetter climate increases the S mineralization and leaching loss, SO42- adsorption is an important S retention process in the subsurface. The vertical distribution of S isotope compositions in the soil profiles across the four sites indicates (i) a downward increase in δ34S values in the upper profiles due to continuous mineralization of organic S with an occasional decrease in δ34S values in the subsurface due to dissimilatory sulfate reduction (DSR), (ii) constantly high δ34S values in the middle profiles due to the low water permeability, and (iii) a downward decrease in δ34S values in the low profiles due to increased contribution of bedrock with depth. Regardless of the variation in soil depth and climate, the total S concentration is proportional to the pedogenic Fe/Al minerals, suggesting the important role of secondary Fe/Al minerals in retaining S in soils. This study provides an integration and synthesis of controls of climatic and edaphic variables on S dynamics in forest soil profiles developed on granite.


Assuntos
Florestas , Solo , Dióxido de Silício , Enxofre
19.
J Colloid Interface Sci ; 599: 351-359, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33962196

RESUMO

High specific surface area, hierarchical porosity, high conductivity and heteroatoms doping have been considered as the dominating factors of high-performance carbon-based supercapacitors. Inspired by the blue phenomenon of combination of starch and iodine, iodine is employed firstly as pore-making agent to create micropores for the starch-derived carbon in this study. Based on this mechanism, the hierarchically porous carbon is synthesized through simple solvent heating and high-temperature (1000 °C) carbonization, which achieves high specific surface area of 2989 m2 g-1 (an increase of 39.7% compared to that without iodine) and low electrical resistivity of 0.21â€¯Ω·cm. The assembled symmetric supercapacitors, combined with dual redox-active electrolyte (Bi3+ and Br-), deliver the specific capacitance of 1216 F g-1, energy density of 65.4 Wh kg-1, as well as power density of 787.3 W kg-1 at 2 A g-1. In brief, the abundant biomass resource starch is exploited as carbon source, and the iodine sublimation reaction is conducted to provide more micropores to develop high-performance electrodes of supercapacitors.


Assuntos
Carbono , Iodo , Biomassa , Capacitância Elétrica , Porosidade
20.
J Colloid Interface Sci ; 599: 795-804, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33989932

RESUMO

Constructing effective interphase boundary is one of the efficient approaches for improving photocatalytic performances of semiconductor materials. In this work, an anatase/rutile-TiO2 (AR-TiO2) heterophase junction with appropriate carbon content was successfully fabricated via an in-situ phase transformation process. The phase transformation started from the inner core of the nanoparticles and the area of phase interface between anatase and rutile was carefully controlled by regulating the activation temperature. The well-established type-II band alignment between two TiO2 phases with residual carbon as additional charge transfer intermediary which significantly improved the light-harvesting and photoinduced electron-hole pair separation. As a result, the optimal AR-TiO2-550 catalyst (without adding commonly used Pt as co-catalyst) remarkably enhanced photocatalytic H2 generation (201 µmol h-1 g-1), which was about 12-fold to that of P25. The AR-TiO2-550 heterophase junction also showed long-term stability under simulated solar light irradiation. This research provides a new phase engineering route for developing high-efficient photocatalysts.

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