Herein, we report a simple synthesis of PtNiCo trimetallic nanoparticles (NPs) loaded on carbon black (PtNiCo/C) via ambient-temperature chemical reduction and galvanic replacement reaction. The influence of thermal treatment temperature in 10 %H 2 /N 2 on PtNiCo NPs in PtNiCo/C-X nanostructures is revealed, where, X = 200 °C, 500 °C. XRD, XPS, TEM, HAADF-STEM, HRTEM, STEM-EDX elemental line-scanning (mapping), HS-LEIS, H 2 -TPR, atomic resolution aberration-corrected STEM (AC-STEM), XANES and EXAFS have been employed to characterize various nanostructures of PtNiCo NPs in PtNiCo/C-X. We established the relationship of nanostructure-reducing temperature thus catalytic behavior of PtNiCo/C-X: PtNiCo/C-200 ∼ Pt island (single atom and cluster)-on-NiCo alloy NP, PtNiCo/C-500 ∼ PtNiCo alloy NPs. PtNiCo/C-200 provides much improved catalytic activity and selectivity to target products ( NO 2 group hydrogenation) as compared to PtNiCo/C-500 for nitroarenes selective hydrogenation under mild reaction conditions (1.0 MPa-H 2 pressure, 18 °C or 40 °C-reaction temperature). That is considered to be closely correlated with the synergy effect of Pt islands and NiCo alloy nanoparticles in PtNiCo/C-200.
Aggregation-induced emission (AIE) active fluorescent polymeric nanoparticles (FPNs) have recently emerged as the promising nanoprobes for biological imaging for their intensive fluorescence, good photostability, desirable biocompatibility and well designability of structure and optical properties. Herein, we proposed a novel strategy for fabrication of AIE-active FPNs through the post modification of synthetic copolymers to form Schiff base. The size, morphology, optical properties and biocompatibility as well as cell uptake behavior were evaluated in detailed. To fabricate these AIE-active FPNs, poly(PEG- co -VA) copolymers were first obtained via addition-fragmentation chain transfer polymerization using poly(ethylene glycol) methyl ether methacrylate (PEGMA) and 3-vinylaniline (VA) as the monomers. Then the AIE-active SA-poly(PEG- co -VA) FPNs were formed through the reaction between salicylaldehyde (SA) and VA. Results demonstrated that SA-poly(PEG- co -VA) FPNs possess bright fluorescence, superior photo-bleaching resistance, excellent biocompatibility and efficient cell uptake behavior. To the best of our knowledge, this is the first report for fabrication AIE-active FPNs through post modification of synthetic copolymers. The facile fabrication procedure and the remarkable features suggested that these AIE-active FPNs promising candidates for biomedical applications.
Ziyue Wang,Ying Zhang,Hao Zhang,Qingdi Sun,Xiaohui He,Hongbing Ji
As worldwide plastic pollution continues to rise, innovative ideas for effective reuse and recycling of waste plastic are needed. Single-atom catalysts (SACs), which are known for their high activity and selectivity, present unique advantages in facilitating plastic degradation and conversion. Waste plastic can be used as a support or raw material to create SACs, which reduces waste generation while simultaneously utilizing waste as a resource. This work successfully utilized waste plastic polyurethane (PU) as a support, through a unique Rapid Thermal Processing Reactor (RTPR) to synthesize an efficient Pd1/PU SACs. At 25 °C and 0.5 MPa H2, Pd1/PU displayed outstanding activity and selectivity in the hydrogenation of styrene, as well as remarkable stability. Pd1/PU performed well in hydrogenating a variety of common substrates. These findings highlight the great potential of SACs in plastic waste reuse and recycling, offering intriguing solutions to the global plastic pollution problem.
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