RESUMO
Defect engineering of metal-organic frameworks (MOFs) is a versatile approach to tailoring their electronic structures and photocatalytic performance. Herein, Ce-based porphyrin MOFs (CMFs) featuring controlled structural defects were successfully prepared using a simple acid modulation strategy to drive the photocatalytic H2 generation. The [Ce-O] unit serves as the active site via a ligand-to-metal charge transfer process, which has been confirmed by in situ XPS analysis. Abundant exposed coordinatively unsaturated Ce-O centers are beneficial for the adsorption and activation of water molecules, which is an important factor for improving the photocatalytic performance of the synthesized defective MOFs. In addition, optical and electrochemical experiments indicate that CMFs with more oxygen vacancies possess higher charge separation efficiency. As a result, the optimized CMF(Zn)-200 sample afforded high stability and activity in the H2 generation (up to 1603.3 µmol·g-1·h-1 under cocatalyst-free conditions) and tetracycline hydrochloride removal efficiency (97%), which was 8.45 and 97 times higher than that of pure meso-tetra(4-carboxyphenyl)porphine. This study demonstrates that effective structural modulation and defect introduction can improve the activity and stability of PMOF-based photocatalysts.
RESUMO
It is highly desirable but challenging to optimize the electronic structure of an active site to realize moderate active site-Hads bond energies for boosting photocatalytic H2 evolution. Herein, an interfacial engineering strategy is developed to simultaneously concentrate hydrogen species and accelerate the combination of an Hads intermediate to generate free H2 by constructing W-WC-W2C (WCC) cocatalysts. Systematic investigations reveal that hybridizing with W2C creates electron-rich W active sites and effectively induces the downshift of the d-band center of W in WC. Consequently, the strong W-Hads bonds on the surface of WC are weakened, thus promoting the desorption of Hads to rapidly produce free H2. The optimized 40-WCC/CdS photocatalyst exhibits a high hydrogen evolution rate of 63.6 mmol g-1 h-1 under visible light (≥420 nm) with an apparent quantum efficiency of 39.5% at 425 nm monochromatic light, which is about 40-fold of the pristine CdS. This work offers insights into the design of cocatalyst for high-efficiency photocatalytic H2 production.
RESUMO
BACKGROUND: Recent research indicates that systemic inflammation significantly affects the overall prognosis of individuals with aneurysmal subarachnoid hemorrhage. To delve deeper into this issue, a retrospective study was undertaken. The study aimed to investigate the relationship between fibrinogen and neutrophil/lymphocyte ratio scores, D-dimer/Albumin ratios, and the Glasgow Outcome Scale at 6 months post-discharge for patients with aSAH. METHODS: A retrospective analysis was conducted on 321 patients who experienced aneurysmal subarachnoid hemorrhage. These patients were monitored using the Glasgow Outcome Scale six months after being discharged from Huizhou Central People's Hospital. Patients with GOS scores between 1 and 3 were classified as having a poor prognosis, while those with scores ranging from 4 to 5 were considered to have a good prognosis. To create distinct sets, patients were randomly divided into both training and validation groups. The best cut-off value for the D-dimer/Albumin ratio was established through ROC curves, and the scores for fibrinogen and the neutrophil/lymphocyte ratio were calculated. Utilizing multivariate logistic regression analysis, independent risk factors linked to an unfavorable prognosis in aSAH patients were identified. A nomogram model was developed and validated based on these findings, providing an improved approach for evaluating the prognostic influence of risk factors. To gauge the model's predictive performance, several analytical tools such as ROC curves, calibration curves, and decision curve analysis were employed. This comprehensive approach ensured a thorough assessment of the prognostic prediction capabilities of the model. RESULTS: Multivariate regression analysis revealed that Age (OR=3.87, 95%CI=1.54-9.73, p=0.004), Pneumonia (OR=3.54, 95%CI=1.41-8.86, p=0.007), WFNS (OR=3.24, 95%CI=1.23-8.54, p=0.017), DAR (OR=2.88, 95%CI=1.13-7.34, p=0.027), and F-NLR (OR=3.12, 95%CI=1.22-7.97, p=0.017) were identified as independent risk factors influencing the prognosis of patients with aSAH. Additionally, the area under the ROC curve was 0.866 (95%CI=0.805-0.927) for the training set and 0.924 (95%CI=0.849-0.999) for the validation set. The calibration curve analysis demonstrated a minor error of 0.02 for the training set and 0.051 for the validation set. Furthermore, both the training set and validation set displayed significant clinical benefits according to the DCA curves, underscoring the meaningful utility of the developed nomogram. CONCLUSIONS: Fibrinogen and neutrophil/lymphocyte ratio scores, and the D-dimer/Albumin ratio emerged as significant independent risk factors for prognosticating the outcomes of patients with aSAH. Leveraging these factors, a robust nomogram model was meticulously developed, showcasing its impressive precision in prognostic predictions. These results underscore the promising clinical applicability of these biomarkers as effective prognostic indicators for individuals afflicted by aSAH.
RESUMO
Developing light-harvesting materials with broad spectral response is of fundamental importance in full-spectrum solar energy conversion. We found that, when a series of earth-abundant metal (Cu, Co, Ni and Fe) salts are dissolved in coordinating solvents uniformly dispersed nanodots (NDs) are formed rather than fully dissolving as molecular species. The previously unrecognized formation of this condensed state is ascribed to spontaneous aggregation of molecular transition-metal-complexes (TMCs) via weak intermolecular interactions, which results in redshifted and broadened absorption into the NIR region (200-1100â nm). Typical photoredox reactions, such as carbonylation and oxidative dehydrogenation, well demonstrate the feasibility of efficient utilization of NIR light (λ>780â nm) by TMCs NDs. Our finding provides a conceptually new strategy for extending the absorption towards low energy photons in solar energy harvesting and conversion via photoredox transformations.