44 research outputs found
Magnetic Nanoscaled Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub> Composite as an Efficient Fenton-Like Heterogeneous Catalyst for Degradation of 4‑Chlorophenol
Magnetic nanoscaled Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub> composite was prepared by the impregnation method and characterized
as a heterogeneous Fenton-like catalyst for 4-chlorophenol (4-CP)
degradation. The catalytic activity was evaluated in view of the effects
of various processes, pH value, catalyst addition, hydrogen peroxide
(H<sub>2</sub>O<sub>2</sub>) concentration, and temperature, and the
pseudo-first-order kinetic constant of 0.11 min<sup>–1</sup> was obtained for 4-CP degradation at 30 °C and pH 3.0 with
30 mM H<sub>2</sub>O<sub>2</sub>, 2.0 g L<sup>–1</sup> Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub>, and 0.78 mM 4-CP. The high
utilization efficiency of H<sub>2</sub>O<sub>2</sub>, calculated as
79.2%, showed a promising application of the catalyst in the oxidative
degradation of organic pollutants. The reusability of Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub> composite was also investigated after
six successive runs. On the basis of the results of metal leaching,
the effects of radical scavengers, intermediates determination, and
X-ray photoelectron spectroscopic (XPS) analysis, the dissolution
of Fe<sub>3</sub>O<sub>4</sub> facilitated by CeO<sub>2</sub> played
a significant role, and 4-CP was decomposed mainly by the attack of
hydroxyl radicals (•OH), including surface-bound •OH<sub>ads</sub> generated by the reaction of Fe<sup>2+</sup> and Ce<sup>3+</sup> species with H<sub>2</sub>O<sub>2</sub> on the catalyst
surface, and •OH<sub>free</sub> in the bulk solution mainly
attributed to the leaching of Fe
Magnetic Nanoscaled Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub> Composite as an Efficient Fenton-Like Heterogeneous Catalyst for Degradation of 4‑Chlorophenol
Magnetic nanoscaled Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub> composite was prepared by the impregnation method and characterized
as a heterogeneous Fenton-like catalyst for 4-chlorophenol (4-CP)
degradation. The catalytic activity was evaluated in view of the effects
of various processes, pH value, catalyst addition, hydrogen peroxide
(H<sub>2</sub>O<sub>2</sub>) concentration, and temperature, and the
pseudo-first-order kinetic constant of 0.11 min<sup>–1</sup> was obtained for 4-CP degradation at 30 °C and pH 3.0 with
30 mM H<sub>2</sub>O<sub>2</sub>, 2.0 g L<sup>–1</sup> Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub>, and 0.78 mM 4-CP. The high
utilization efficiency of H<sub>2</sub>O<sub>2</sub>, calculated as
79.2%, showed a promising application of the catalyst in the oxidative
degradation of organic pollutants. The reusability of Fe<sub>3</sub>O<sub>4</sub>/CeO<sub>2</sub> composite was also investigated after
six successive runs. On the basis of the results of metal leaching,
the effects of radical scavengers, intermediates determination, and
X-ray photoelectron spectroscopic (XPS) analysis, the dissolution
of Fe<sub>3</sub>O<sub>4</sub> facilitated by CeO<sub>2</sub> played
a significant role, and 4-CP was decomposed mainly by the attack of
hydroxyl radicals (•OH), including surface-bound •OH<sub>ads</sub> generated by the reaction of Fe<sup>2+</sup> and Ce<sup>3+</sup> species with H<sub>2</sub>O<sub>2</sub> on the catalyst
surface, and •OH<sub>free</sub> in the bulk solution mainly
attributed to the leaching of Fe
Effect of Pore Size Distribution of Carbon Matrix on the Performance of Phosphorus@Carbon Material as Anode for Lithium-Ion Batteries
Phosphorus@carbon composites are
alternative anode materials for
lithium-ion batteries due to their high specific capacity. Serving
as a conductive and buffer matrix, the carbon substrate is important
to the performance of the composite. Our results exhibit that the
electrochemical performances of phosphorus@carbon composites could
be significantly enhanced by pore size distributions of the carbon
matrix. The initial Coulombic efficiency of phosphorus@YP-50F reaches
80% and the capacity remains stable at 1370 mAh g<sup>–1</sup> after 100 cycles at 300 mA g<sup>–1</sup>. The work may provide
a general strategy for designing or selecting the optimal carbon matrix
for phosphorus@carbon performance, and pave the way to practical application
in lithium-ion batteries
Clinically Approved Ferric Maltol: A Potent Nanozyme with Added Effect for High-Efficient Catalytic Disinfection
Nanozyme has been proven to be an attractive and promising
candidate
to alleviate the current pressing medical problems. However, the unknown
clinical safety and limited function beyond the catalysis of the most
reported nanozymes cannot promise an ideal therapeutic outcome in
further clinical application. Herein, we find that ferric maltol (FM),
a clinically approved iron supplement synthesized through a facile
scalable method, exhibits excellent peroxidase-like activity than
natural horseradish peroxidase-like (HRP) and commonly reported Fe-based
nanozymes, and also shows high antibacterial performance for methicillin-resistant Staphylococcus aureus (MRSA) elimination (100%) and
wound disinfection. In addition, with added effects inherited from
contained maltol, FM can accelerate skin barrier recovery. Therefore,
the exploration of FM as a safe and desired nanozyme provides a timely
alternative to current antibiotic therapy against drug-resistant bacteria
Can the digital economy address the loss of green development efficiency due to resource mismatch? Evidence from China’s land transaction markets
Land is the driving force of economic growth, but the proliferation of industrial land has resulted in wasted land resources, impaired economic efficiency, and ecological damage in China. Currently, the digital economy is transforming China’s economic growth model. Exploring the corrective mechanisms of the digital economy for land resource mismatch can contribute to efficient economic growth. Using a sample of Chinese prefecture-level cities from 2007–2019, we employ a spatial Durbin model to explore the impact of land resource mismatch on green development efficiency (GDE) in the context of the digital economy, which is critical to rational planning, utilization, and regulation of land resources. The findings show that (1) land resource mismatch inhibits GDE, and the crowding-out, structural inhibition, and agglomeration economy dilution effect are primary influencing mechanisms. (2) A local land resource mismatch harms GDE in neighboring areas. (3) The digital economy has a positive moderating effect on land resource mismatch and GDE. (4) Land resource mismatch reduces GDE in the eastern and central regions; the moderating effect of the digital economy exists only in the eastern region. Finally, this study proposes comprehensive and complete countermeasures to correct the land resource mismatch and its influence channels and enhance the construction of the digital economy. The conclusions of this study provide specific theoretical contributions to promote the spatial allocation efficiency of land resources, promote green and efficient economic development, and stimulate and release the dividends of the digital economy.</p
Crystal Orientation Tuning of LiFePO<sub>4</sub> Nanoplates for High Rate Lithium Battery Cathode Materials
We report the crystal orientation tuning of LiFePO<sub>4</sub> nanoplates
for high rate lithium battery cathode materials. Olivine LiFePO<sub>4</sub> nanoplates can be easily prepared by glycol-based solvothermal
process, and the largest crystallographic facet of the LiFePO<sub>4</sub> nanoplates, as well as so-caused electrochemical performances,
can be tuned by the mixing procedure of starting materials. LiFePO<sub>4</sub> nanoplates with crystal orientation along the <i>ac</i> facet and <i>bc</i> facet present similar reversible capacities
of around 160 mAh g<sup>–1</sup> at 0.1, 0.5, and 1 C-rates
but quite different ones at high C-rates. The former delivers 156
mAh g<sup>–1</sup> and 148 mAh g<sup>–1</sup> at 5 C-rate
and 10 C-rate, respectively, while the latter delivers 132 mAh g<sup>–1</sup> and only 28 mAh g<sup>–1</sup> at 5 C-rate
and 10 C-rate, respectively, demonstrating that the crystal orientation
plays important role for the performance of LiFePO<sub>4</sub> nanoplates.
This paves a facile way to prepare high performance LiFePO<sub>4</sub> nanoplate cathode material for lithium ion batteries
Nitrogen-Enriched Hierarchically Porous Carbons Prepared from Polybenzoxazine for High-Performance Supercapacitors
Nitrogen-enriched hierarchically
porous carbons (HPCs) were synthesized
from a novel nitrile-functionalized benzoxazine based on benzoxazine
chemistry using a soft-templating method and a potassium hydroxide
(KOH) chemical activation method and used as electrode materials for
supercapacitors. The textural and chemical properties could be easily
tuned by adding a soft template and changing the activation temperature.
The introduction of the soft-templating agent (surfactant F127) resulted
in the formation of mesopores, which facilitated fast ionic diffusion
and reduced the internal resistance. The micropores of HPCs were extensively
developed by KOH activation to provide large electrochemical double-layer
capacitance. As the activation temperature increased from 600 to 800
°C, the specific surface area of nitrogen-enriched carbons increased
dramatically, micropores were enlarged, and more meso/macropores were
developed, but the nitrogen and oxygen content decreased, which affected
the electrochemical performance. The sample HPC-800 activated at 800
°C
possesses a high specific surface area (1555.4 m<sup>2</sup> g<sup>–1</sup>), high oxygen (10.61 wt %) and nitrogen (3.64 wt
%) contents, a hierarchical pore structure, a high graphitization
degree, and good electrical conductivity. It shows great pseudocapacitance
and the largest specific capacitance of 641.6 F g<sup>–1</sup> at a current density of 1 A g<sup>–1</sup> in a 6 mol L<sup>–1</sup> KOH aqueous electrolyte when measured in a three-electrode
system. Furthermore, the HPC-800 electrode exhibits excellent rate
capability (443.0 F g<sup>–1</sup> remained at 40 A g<sup>–1</sup>) and good cycling stability (94.3% capacitance retention over 5000
cycles)
Establishing the Interface Layer on the Pentaerythritol Tetranitrate Surface <i>via In Situ</i> Reaction
Pentaerythritol tetranitrate (PETN) was coated by tannic
acid (TA),
polydopamine (PDA), and melamine-formaldehyde (MF) resins via in situ reaction to prepare PETN@TA, PETN@PDA, and PETN@MF
microcapsules for reducing sensitivity and enhancing thermal stability
of PETN. The coating effects of TA, PDA, and MF shells on PETN surfaces
are characterized by scanning electron microscopy and atomic force
microscopy. The structures of PETN@TA, PETN@PDA, and PETN@MF microcapsules
are characterized by X-ray photoelectron spectroscopy, X-ray diffraction,
and Fourier-transform infrared spectra. The performances of PETN@TA,
PETN@PDA, and PETN@MF microcapsules are characterized by differential
scanning calorimetry, accelerating rate calorimetry, explosion point,
vacuum deflation volume, and mechanical sensitivity. The study results
show that TA, PDA, and MF shells can coat the PETN surface well. Compared
with pure PETN, the explosion point has an increase while the vacuum
deflation volume and mechanical sensitivity have a decrease for PETN@TA,
PETN@PDA, and PETN@MF microcapsules, illustrating that the safeties
of PETN@TA, PETN@PDA, and PETN@MF microcapsules are enhanced. In addition,
the initial decomposition temperature (T0) and peak decomposition temperature (Tp) of PETN@TA, PETN@PDA, and PETN@MF microcapsules have a slight increase,
demonstrating that the thermal stabilities of PETN@TA, PETN@PDA, and
PETN@MF microcapsules are better than that of pure PETN. The obtained
method can provide some guidance for the desensitizing of other energetic
materials with high sensitivities
DataSheet_1_A simplified frailty index and nomogram to predict the postoperative complications and survival in older patients with upper urinary tract urothelial carcinoma.docx
PurposeThis study was designed to investigate the clinical value of a simplified five-item frailty index (sFI) for predicting short- and long-term outcomes in older patients with upper urinary tract urothelial carcinoma (UTUC) patients after radical nephroureterectomy (RNU).MethodThis retrospective study included 333 patients (aged ≥65 years) with UTUC. Patients were classified into five groups: 0, 1, 2, 3, and 3+, according to sFI score. The variable importance and minimum depth methods were used to screen for significant variables, and univariable and multivariable logistic regression models applied to investigated the relationships between significant variables and postoperative complications. Survival differences between groups were analyzed using Kaplan-Meier plots and log-rank tests. Cox proportional hazards regression was used to evaluate risk factors associated with overall survival (OS) and cancer-specific survival (CSS). Further, we developed a nomogram based on clinicopathological features and the sFI. The area under the curve (AUC), Harrel’s concordance index (C-index), calibration curve, and decision curve analysis (DCA) were used to evaluate the nomogram.ResultOf 333 cases identified, 31.2% experienced a Clavien-Dindo grade of 2 or greater complication. Random forest–logistic regression modeling showed that sFI significantly influenced the incidence of postoperative complications in older patients (AUC= 0.756). Compared with patients with low sFI score, those with high sFI scores had significantly lower OS and CSS (p ConclusionA simple five-item frailty index may be considered a prognostic factor for the prognosis and postoperative complications of UTUC following RNU. By using this predictive model, clinicians may increase their accuracy in predicting complications and prognosis and improve preoperative decision-making.</p
Surface Engineering of a Nickel Oxide–Nickel Hybrid Nanoarray as a Versatile Catalyst for Both Superior Water and Urea Oxidation
Developing
efficient and low-cost oxygen evolution reaction (OER) electrodes
is a pressing but still challenging task for energy conversion technologies
such as water electrolysis, regenerative fuel cells, and rechargeable
metal–air batteries. Hence, this study reports that a nickel
oxide–nickel hybrid nanoarray on nickel foam (NiO–Ni/NF)
could act as a versatile anode for superior water and urea oxidation.
Impressively, this anode could attain high current densities of 50
and 100 mA cm<sup>–2</sup> at extremely low overpotentials
of 292 and 323 mV for OER, respectively. Besides, this electrode also
shows excellent activity for urea oxidation with the need for just
0.28 and 0.36 V (vs SCE) to attain 10 and 100 mA cm<sup>–2</sup> in 1.0 M KOH with 0.33 M urea, respectively. The enhanced oxidation
performance should be due to the synergistic effect of NiO and Ni,
improved conductivity, and enlarged active surface area