CO₂ Adsorption Behavior and Kinetics on Amine-Functionalized Composites Silica with Trimodal Nanoporous Structure

A trimodal porous support with special trimodal pore structure has been prepared by physically mixing the silica gel (HPS) and SBA-15 and then devoted to fabricate TEPA<b>-</b>functionalized adsorbent for CO₂ capture. The trimodal multistage mesopores structure can promote the TEPA dispersion and mitigate the mass-transfer resistance in the adsorbent and, hence, improve capture performance, compared to the single mesoporous support. The influence of the mass ratios of HPS to SBA-15, amine loaded amount, CO₂ concentration, adsorption temperatures, and water vapor were studied. The CO₂-saturated adsorption amount of 5.05 mmol/g was obtained at 75 °C in dry N₂ flow containing 15 vol % CO₂ when the mass ratio of SBA-15 to HPS was 1:2 with 50 wt % TEPA loadings. Moreover, the CO₂-saturated adsorption amount presented a 16% improvement in humid N₂ flow containing 15 vol % CO₂ flow at 75 °C. In addition, the S2HPS-TEPA50% also demonstrated good stability after 10 adsorption/desorption cycles. Based on in situ DRIFTS results of CO₂ adsorption/desorption process, the reaction mechanism of CO₂ with active sites was proposed by analyzing the relationships among variations of intensities of functional groups during the reaction. The intraparticle diffusion model was adapted to study CO₂ kinetics and the intraparticle diffusion prediction indicated that boundary layer diffusion was the rate-controlling step in the process of CO₂ capture. Overall, these results indicate that S2HPS-TEPA50% is promising for CO₂ capture

Excitation of Surface Plasmon Resonance in Composite Structures Based on Single-Layer Superaligned Carbon Nanotube Films

Surface-enhanced Raman scattering (SERS) provides valuable information on the vibrational modes of molecules and the physical mechanism of surface plasmon resonance (SPR). In this paper we study the localized SPR process in Ag- or Ag/oxide-coated single-layer superaligned carbon nanotube (SACNT) films. Because of the unidirectional alignment of the carbon nanotubes in these films, the Raman signal is higher when the laser is polarized parallel to the aligned direction than when perpendicular to it. We investigated the polarization-dependent transmittance and Raman spectra for various Ag particle sizes and different oxide medium layers to study the localized SPR in these composite structures. These results systematically characterize the properties of SACNT film-based SERS substrates and clarify the origin of transmittance peaks

Controlled Growth of Pd Nanocrystals by Interface Interaction on Monolayer MoS₂: An Atom-Resolved <i>in Situ</i> Study

The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas–solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials

Organic–Inorganic Hybrid Interfacial Layer for High-Performance Planar Perovskite Solar Cells

4,7-Diphenyl-1,10-phenanthroline (Bphen) is an efficient electron transport and hole blocking material in organic photoelectric devices. Here, we report cesium carbonate (Cs₂CO₃) doped Bphen as cathode interfacial layer in CH₃NH₃PbI_3–<i>x</i>Cl_<i>x</i> based planar perovskite solar cells (PSCs). Investigation finds that introducing Cs₂CO₃ suppresses the crystallization of Bphen and benefits a smooth interface contact between the perovskite and electrode, resulting in the decrease in carrier recombination and the perovskite degradation. In addition, the matching energy level of Bphen film in the PSCs effectively blocks the holes diffusion to cathode. The resultant power conversion efficiency (PCE) achieves as high as 17.03% in comparison with 12.67% of reference device without doping. Besides, experiments also demonstrate the stability of PSCs have large improvement because the suppressed crystallization of Bphen by doping Cs₂CO₃ as a superior barrier layer blocks the Ag atom and surrounding moisture access to the vulnerable perovskite layer

Additional file 1 of Conteltinib (CT-707) in patients with advanced ALK-positive non-small cell lung cancer: a multicenter, open-label, first-in-human phase 1 study

Additional file 1: Table S1. In vitro potency of crizotinib and conteltinib (CT-707). Table S2. Intracranial response of conteltinib (CT-707) in ALK-positive patients with brain metastasis

Controlled Growth of Pd Nanocrystals by Interface Interaction on Monolayer MoS₂: An Atom-Resolved <i>in Situ</i> Study

The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas–solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials

Controlled Growth of Pd Nanocrystals by Interface Interaction on Monolayer MoS₂: An Atom-Resolved <i>in Situ</i> Study

The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas–solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials

Controlled Growth of Pd Nanocrystals by Interface Interaction on Monolayer MoS₂: An Atom-Resolved <i>in Situ</i> Study

The crystal growth kinetics is crucial for the controllable preparation and performance modulation of metal nanocrystals (NCs). However, the study of growth mechanisms is significantly limited by characterization techniques, and it is still challenging to in situ capture the growth process. Real-time and real-space imaging techniques at the atomic scale can promote the understanding of microdynamics for NC growth. Herein, the growth of Pd NCs on monolayer MoS2 under different atmospheres was in situ studied by environmental transmission electron microscopy. Introducing carbon monoxide can modulate the diffusion of Pd monomers, resulting in the epitaxial growth of Pd NCs with a uniform orientation. The electron energy loss spectroscopy and theoretical calculations showed that the CO adsorption assured the specific exposed facets and good uniformity of Pd NCs. The insight into the gas–solid interface interaction and the microscopic growth mechanism of NCs may shed light on the precise synthesis of NCs on two-dimensional (2D) materials

Surface Modification of Magnetic ZIF-90 Nanoparticles Improves the Microenvironment of Immobilized Lipase and Its Application in Esterification

Interactions of enzymes with supports significantly affect the activity and stability of immobilized enzymes. Herein, amino-functionalized ionic liquid (IL)-grafted magnetic zeolitic imidazolate framework-90 (MZIF-90) was prepared and used to immobilize porcine pancreatic lipase (PPL). The nanocomposites were fully characterized; meanwhile, the interactions between ILs and ZIF-90 were calculated based on density functional theory. The prepared biocatalyst (PPL-ILs/MZIF-90) had a lipase loading of 178.3 mg/g and hydrolysis activity up to 287.5 U/g. When the biocatalyst was used to synthesize isoamyl acetate, the reaction media, molar ratio of alcohol/acid, temperature, and reaction time were optimized. Under the optimized reaction conditions (in hexane, alcohol/acid = 3:1, under 45 °C, reacted for 9 h), the ester yield reached 85.5%. The results of the stability test showed that PPL-ILs/MZIF-90 retained 88.7% of the initial activity after storing for 35 days and 92.5% of the initial activity after reusing for seven cycles for synthesizing isoamyl acetate. Moreover, the secondary structure analysis showed that the synthesized supports protected the active conformation of immobilized lipase, which lead to the enhanced catalytic performance. Additionally, the biocatalyst can be easily separated with a magnet, which facilitated the reusability. This study provides insights regarding the application of metal organic framework composites in the field of enzyme catalysis

Probing Local Strain at MX₂–Metal Boundaries with Surface Plasmon-Enhanced Raman Scattering

Interactions between metal and atomically thin two-dimensional (2D) materials can exhibit interesting physical behaviors that are of both fundamental interests and technological importance. In addition to forming a metal–semiconductor Schottky junction that is critical for electrical transport, metal deposited on 2D layered materials can also generate a local mechanical strain. We investigate the local strain at the boundaries between metal (Ag, Au) nanoparticles and MX₂ (M = Mo, W; X = S) layers by exploiting the strong local field enhancement at the boundary in surface plasmon-enhanced Raman scattering (SERS). We show that the local mechanical strain splits both the in-plane vibration mode E_2g¹ and the out-of-plane vibration mode A_1g in monolayer MoS₂, and activates the in-plane mode E_1g that is normally forbidden in backscattering Raman process. In comparison, the effects of mechanical strain in thicker MoS₂ layers are significantly weaker. We also observe that photoluminescence from the indirect bandgap transition (when the number of layers is ≥2) is quenched with the metal deposition, while a softened and broadened shoulder peak emerges close to the original direct-bandgap transition because of the mechanical strain. The strain at metal–MX₂ boundaries, which locally modifies the electronic and phonon structures of MX₂, can have important effects on electrical transport through the metal–MX₂ contact