This contribution describes the preparation of multifunctional yolk–shell nanoparticles (YSNs) consisting of a core of silica spheres and an outer shell based on periodic mesoporous organosilica (PMO) with perpendicularly aligned mesoporous channels. The new yolk–shell hybrid materials were synthesised through a dual mesophase and vesicle soft templating method. The mesostructure of the shell, the dimension of the hollow space (4∼52 nm), and the shell thickness (16∼34 nm) could be adjusted by precise tuning of the synthesis parameters, as evidenced by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and nitrogen sorption investigations. Various metal nanoparticles (e.g., Au, Pt, and Pd) were encapsulated and confined in the void space between the core and the shell using impregnation and reduction of adequate metal precursors. The selective oxidation of various alcohol substrates was then carried out to illustrate the benefits of such an architecture in catalysis. High conversion (∼100%) and excellent selectivity (∼99%) were obtained over Pd nanoparticles encapsulated in the hybrid PMO yolk–shell structures.

Silver nanoparticle aggregates were synthesized on copper foil, which was used for the surface-enhanced Raman spectroscopy (SERS) detection of polycyclic aromatic hydrocarbons (PAHs) with a portable Raman spectrometer. Silver nanoparticle aggregates were prepared by immersing copper foil in the solution of Sn(2+) and AgNO(3) in a cyclic fashion. A four-cycle process was selected for the following experiments due to its high enhancement and relatively convenient experimental procedure. The substrate has greater temporal stability under continuous laser radiation, good uniformity and reproducibility, which indicated that the substrate could provide reliable measurements. The relationship between SERS intensity and concentrations of PAHs was studied. Quantitative analysis of PAHs in aqueous solution was further performed based on the prepared substrate. The log-log plot of normalized SERS intensity to PAHs concentration exhibited a good linear relationship, with the detection limits in the range of 5-500 μg L(-1). Thus, due to the stability, reproducibility and quantitative results, the prepared substrate could be used as a potential SERS sensor for the analysis of environmental pollutants.

Antimony telluride (Sb2Te3) and its based alloys are of importance to p-type semiconductors for thermoelectric applications near room temperature. Herein, we report a simple, low-energy intensive, and scalable surfactant-assisted reflux method for the synthesis of Sb2Te3 nanoparticles in the solvent ethylene glycol (EG) at low temperatures (120-180 °C). The formation mechanism of platelike Sb2Te3 nanoparticles is proposed. Also, it is found that the size, shape, and chemical composition of the products could be controlled by the introduction of organic surfactants (CTAB, PVP, etc.) or inorganic salts (EDTA-Na2, NaOH, etc.). Additionally, the collected Sb2Te3 nanoparticles were further fabricated into nanostructured pellets using cold-compaction and annealing techniques. Low resistivity [(7.37-19.4) × 10(-6) Ω m], moderate Seebeck coefficient (103-141 μV K(-1)), and high power factor (10-16 × 10(-4) W m(-1) K(-2)) have been achieved in our Sb2Te3-nanostructured bulk materials. The relatively low thermal conductivity (1.32-1.55 W m(-1) K(-1)) is attained in the nanobulk made of PVP-modified nanoparticles, and values of ZT in the range of 0.24-0.37 are realized at temperatures ranging from 50 to 200 °C. Our researches set forth a new avenue in promoting practical applications of Sb2Te3-based thermoelectric power generation or cooling devices.

A scintillation screen with ultrahigh spatial resolution, fast decay time, and high stability is the key to commercial application. Herein, a pixelated‐structure scintillation screen of CsPbBr3 nanocrystal arrays based on anodized aluminum oxide (AAO) is reported, and its scintillation properties for X‐ray imaging are explored. It is of note that ultrahigh spatial resolution (2 µm), fast photoluminescence decay time (9 ns), and high stability (>42 d) are successfully achieved by the pixelated CsPbBr3‐AAO arrays scintillation screen. Considering the decent scintillation properties and high stability, one has reason to assume that the pixelated CsPbBr3‐AAO arrays scintillation screen may find an application as a new X‐ray scintillation screen.

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