Robust Amphiphobic Few-Layer Black Phosphorus Nanosheet with Improved Stability.

Few-layer black phosphorus (FL-BP) has been intensively studied due to its attractive properties and great potential in electronic and optoelectronic applications. However, the intrinsic instability of FL-BP greatly limits its practical application. In this study, the amphiphobic FL-BP is achieved by functionalization of 1 H ,1 H ,2 H ,2 H -perfluorooctyltrichlorosilane (PFDTS) on the surface of FL-BP. The obtained PFDTS coated FL-BP (FL-BP/PFDTS) demonstrates enhanced stability, which is not observed during significant degradation for 2 months in high moisture content environment (95% humidity). Particularly, attributing to the surface amphiphobicity, FL-BP/PFDTS exhibits strong surface water repellency in the presence of oleic acid (as the contaminant), while other passivation coating layers (such as hydrophilic or hydrophobic coating) become hydrophilicity under such conditions. Owing to this advantage, the obtained FL-BP/PFDTS demonstrates enhanced stability in high moisture content environment for 2 months, even though the surface is contaminated by oil liquid or other organic solvents (such as oleic acid, CH2Cl2, and N -methyl-2-pyrrolidone). The passivation of FL-BP by amphiphobic coating provides an effective approach for FL-BP stabilization toward future applications

Facile synthesis of high-performance indium nanocrystals for selective CO2-to-formate electroreduction

Selective electrocatalytic reduction of CO2 to formate has received increasing interest for CO2 conversion and utilization. Yet, the CO2 reduction process still faces major challenges, partly due to the lack of cost-effective, highly active, selective and stable electrocatalysts. Here, we report a mesoporous indium (mp-In) electrocatalyst composed of nanobelts synthesized via a simple solution-based approach for selective CO2 reduction to formate. The mp-In nanocrystals provide enlarged surface areas, abundant surface active sites and edge/low-coordinated sites. Such advantages afford the mp-In with an outstanding electrocatalytic performance for the CO2-to-formate conversion. A high formate selectivity, with a Faradaic efficiency (FE) of >90% was achieved over a potential of −0.95 V to −1.1 V (vs VRHE). The mp-In catalyst showed excellent durability, reflected by the stable formate selectivity and current density over a 24 h reaction period. Density functional theory (DFT) calculations reveal that the stabilization of the intermediate OCHO* on the In-plane surfaces is energetically feasible, further elucidating the origin of its enhanced CO2-to-formate activity and selectivity. This work may offer valuable insights for the facile fabrication of porous hierarchical nanostructures for electrocatalytic and selective reduction of CO2.</p

Existence of Positive Solutions for a Kind of Fractional Boundary Value Problems

We are concerned with the following nonlinear three-point fractional boundary value problem: D0+αut+λatft,ut=0, 00 is continuous for 0≤t≤1, and f≥0 is continuous on 0,1×0,∞. By using Krasnoesel'skii's fixed-point theorem and the corresponding Green function, we obtain some results for the existence of positive solutions. At the end of this paper, we give an example to illustrate our main results

Robust Amphiphobic Few‐Layer Black Phosphorus Nanosheet with Improved Stability

Few-layer black phosphorus (FL-BP) has been intensively studied due to its attractive properties and great potential in electronic and optoelectronic applications. However, the intrinsic instability of FL-BP greatly limits its practical application. In this study, the amphiphobic FL-BP is achieved by functionalization of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFDTS) on the surface of FL-BP. The obtained PFDTS coated FL-BP (FL-BP/PFDTS) demonstrates enhanced stability, which is not observed during significant degradation for 2 months in high moisture content environment (95% humidity). Particularly, attributing to the surface amphiphobicity, FL-BP/PFDTS exhibits strong surface water repellency in the presence of oleic acid (as the contaminant), while other passivation coating layers (such as hydrophilic or hydrophobic coating) become hydrophilicity under such conditions. Owing to this advantage, the obtained FL-BP/PFDTS demonstrates enhanced stability in high moisture content environment for 2 months, even though the surface is contaminated by oil liquid or other organic solvents (such as oleic acid, CH2Cl2, and N-methyl-2-pyrrolidone). The passivation of FL-BP by amphiphobic coating provides an effective approach for FL-BP stabilization toward future applications.Ministry of Education (MOE)Published versio

Original Article An analysis on clinicopathological features and prognostic factors of patient with primary hepatic lymphoma

Abstract: Objective: To explore the clinicopathological features and prognostic factors of primary hepatic lymphoma. Methods: A retrospective analysis was performed on the clinicopathological features and follow-up data of 105 patients with PHL in our hospital from January 1980 to October 2012. Survival rates were estimated by Kaplan Meier analysis and prognostic factors were analyzed with Cox regression model. Results: The mean age of patients with PHL was (54.3 ± 14.7) years old and the tumor was 4 to 15 cm in long diameter. In the mode of invasion, nodular invasion accounted for 63.8% (67/105) and diffuse invasion accounted for 36.2% (38/105). In pathological type, diffuse large B-cell lymphoma accounted for 57.1% (60/105), peripheral T-cell lymphoma accounted for 34.3% (36/105) and extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue accounted for 8.6% (9/105). The median survival time of the 105 patients with PHL was 28 months (8~120 months), and the survival rates in 1, 3 and 5 years were 69.5%, 42.9% and 26.7% respectively. Univariate analysis showed that the survival rate was statistically significant among patients with differences in age, number and size of tumor, mode of invasion and pathological type (P &lt; 0.05). Cox proportional hazards regression analysis showed that age above 60 years old (HR = 1.92, 95% CI: 1.28~2.89), tumor size ≥ 10 cm (HR = 2.17, 95% CI: 1.32~3.56), diffuse invasion (HR = 1.79, 95% CI: 1.21~2.65) and peripheral T-cell lymphoma (HR = 2.76, 95% CI: 1.65~4.63) were independent risk factors of prognosis for the patients. Conclusion: The main pathological type of PHL is diffuse large B-cell lymphoma. Old age, tumor size ≥ 10 cm, peripheral T-cell lymphoma and diffuse infiltrative tumor cells are the risk factors of prognosis for patients with PHL

Regulating the reactivity of black phosphorus via protective chemistry

Rationally regulating the reactivity of molecules or functional groups is common in organic chemistry, both in laboratory and industry synthesis. This concept can be applied to inorganic nanomaterials, particularly two-dimensional black phosphorus (BP) nanosheets. The high reactivity of few-layer (even monolayer) BP is expected to be "shut down" when not required and to be resumed upon application. Here, we demonstrate a protective chemistry-based methodology for regulating BP reactivity. The protective step initiates from binding Al3+ with lone pair electrons from P to decrease the electron density on the BP surface, and ends with an oxygen/water-resistant layer through the self-assembly of hydrophobic 1,2-benzenedithiol (BDT) on BP/Al3+ This protective step yields a stabilized BP with low reactivity. Deprotection of the obtained BP/Al3+/BDT is achieved by chelator treatment, which removes Al3+ and BDT from the BP surface. The deprotective process recovers the electron density of BP and thus restores the reactivity of BP.National Research Foundation (NRF)Published versionThis study was financially supported by the National Natural Science Foundation of China (21771154), the Shenzhen Fundamental Research Programs (JCYJ20190809161013453), the Natural Science Foundation of Fujian Province of China (2018J01019 and 2018J05025), and the Fundamental Research Funds for the Central Universities (20720180019 and 20720180016). This research was also supported by the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03)

A hint from phosphine complex: The π back-bonding in cobalt-phosphorene composite enables enhanced electrocatalytic performance

Regulating the electronic structure of the metal electrocatalyst is fundamental for its performance optimizing. The electronic states of the active metal centers are highly dependent on their coordination environment, especially when bonding is formed. The π back-bonding can induce great electron density redistribution around metals, yet it is barely applied in electrocatalyst design. Herein we electrodeposited metallic cobalt on black phosphorus (BP) nanosheets, forming BP-Co with a unique π back-bonding on the interfaces. The BP-Co exhibited high electrocatalytic activity and stability for hydrogen evolution reaction in alkaline electrolyte. The electrochemical and spectroscopic characterizations demonstrated that the BP acted as σ donor and π acceptor to coordinate with electron-rich metallic Co, similar to the phosphine complex. The directional σ bond strengthen the relationship between BP and Co, while the non-directional π bond accelerated the in-plane electron transfer. The π back donation also decreased the oxophilicity of Co to make BP-Co resist the poison from oxygen species. This study can intrigue new thinking prospective for the electrocatalyst design

Porous Indium Nanocrystals on Conductive Carbon Nanotube Networks for High-Performance CO2-to-Formate Electrocatalytic Conversion

Ever-increasing emissions of anthropogenic carbon dioxide (CO2) cause global environmental and climate challenges. Inspired by biological photosynthesis, developing effective strategies NeuNlto up-cycle CO2 into high-value organics is crucial. Electrochemical CO2 reduction reaction (CO2RR) is highly promising to convert CO2 into economically viable carbon-based chemicals or fuels under mild process conditions. Herein, mesoporous indium supported on multi-walled carbon nanotubes (mp-In@MWCNTs) is synthesized via a facile wet chemical method. The mp-In@MWCNTs electrocatalysts exhibit high CO2RR performance in reducing CO2 into formate. An outstanding activity (current density −78.5 mA cm−2), high conversion efficiency (Faradaic efficiency of formate over 90%), and persistent stability (~30 h) for selective CO2-to-formate conversion are observed. The outstanding CO2RR process performance is attributed to the unique structures with mesoporous surfaces and a conductive network, which promote the adsorption and desorption of reactants and intermediates while improving electron transfer. These findings provide guiding principles for synthesizing conductive metal-based electrocatalysts for high-performance CO2 conversion.</p