Black phosphorus quantum dots (BPQDs) have recently obtained great attention owing to their outstanding properties, such as high hole mobility, quantum confinement effect, and edge effect. At present, several methods have been applied to prepare BPQDs using black phosphorus as precursor. In this study, BPQDs are obtained via shock-induced phase transformation using ball-milled red phosphorus nanopowder as precursor. The red phosphorus powder was ball-milled and shocked to induce phase transformation at transient high pressure and temperature. Multiple techniques are applied to characterize the recovered samples, including x-ray diffraction, Raman spectroscopy, transmission electron microscopy, and atomic force microscope. The characterization results demonstrate that the majority of recovered sample is BPQDs with a lateral size of 2–10 nm and a thickness of 0.9–2 nm. In addition, the formation mechanism of BPQDs under shock treatment was carefully analyzed, consisting of phase transformation induced by shock loading and exfoliation by tensile and shear effects. Furthermore, this study also confirms that the micromorphology of precursor is critical to the formation of BPQDs. This research provides an efficient one-step path to prepare BPQDs using ball-milled red phosphorus nanopowder as precursor.

Black phosphorene has received great attention owing to its outstanding properties, such as unique layer-dependent properties in the band gap. In this study, a unique mechanical exfoliation route, liquid-electric effect,...

Si nanoparticle features multiple excellent properties, such as high theoretical capacity of 4200 mAh/g and low volume expansion effect, and it is regarded as an outstanding anode electrode material for Li-ion batteries. In this study, we obtained Si nanoparticles through pulsed discharge of Si strips and analyzed the pulsed discharge process based on recorded current data. The recovered samples were characterized by various techniques, such as XRD, Raman spectroscopy, SEM, and TEM. The characterization results confirm that the recovered samples are smooth spherical Si nanoparticles smaller than 200 nm. Our investigation reveals that the charging voltage is a key factor to adjust the size distribution of recovered Si nanoparticles. In the charging voltage range of 4–7 kV, the increase of charging voltage value decreases D90 (the particle size at the 90% undersize point in the size distribution) of recovered Si nanoparticles from 48.7 to 24.9 nm. In the charging voltage range of 7–12 kV, the increase of charging voltage value increases D90 of recovered Si nanoparticles from 24.9 to 66.5 nm. Thus, the critical charging voltage value is 7 kV, at which condition D90 of formed Si nanoparticles is the minimum (24.9 nm). In addition, the analysis of discharge current curves indicates three discharge stages, including semiconductor joule heating, conductor joule heating, and plasma discharge, which possess correlation to the size distribution of formed Si nanoparticles.

In this study, the highly crystalline black phosphorus nanosheets are obtained via shock-induced phase transformation. Red phosphorus powder is filled in sample container and treated by high shock pressure...

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