A three-dimensional graphene-based composite was prepared by a simple one-step in-site reduced-oxide method under atmospheric pressure. The obtained hydrogel was modified with 4-amino-benzenesulfonic acid and connected with ethylenediamine, and freeze-dried into an aerogel, which was characterized. Then the surface interaction with platinum (Pt, IV) was explored. The obtained aerogel showed good adsorption for Pt (IV) at acid conditions, giving a rising to the adsorption rate > 98% while pH ≥ 6. Using hexadecyl trimethyl ammonium bromide of 2% (m/V) as an eluent to desorb the Pt (IV) from the surface of the aerogel, a desorption rate of 81.1% was obtained in this process. Urea, buffer aquation and other surfactants were used in the desorption experiment to understand the adsorption mechanism between the aerogel and Pt (IV). In this work, hydrogen bond, van der Waals force and electronic interaction force mainly drove the adsorption process. For obtaining more purified Pt (IV), we used 0.5% CTAB to desorb Pd (II). A new three-dimensional graphene-based composite was prepared and the surface interaction between Pt (IV) and composite was experimented for understanding the adsorption mechanism and exploring its potential application in sample preparation in low concentration.

We prepared multilayered Si-based Ge quantum dots (Ge/Si QDs) by using magnetron sputtering technique and reported the corresponding morphology evolution. The increased temperature can improve the Si-isolated-layer crystallinity and Ge atom mobility to increase the density, size and spatial distribution uniformity of top-layer QDs. The morphology and vertical correlation between layers of QDs at different temperatures exhibited different phenomena or laws, and had been explained in this work, which made it possible to control the quality of multilayer QDs more effectively in the high-rate growth, and laid a foundation for the industrial production of active layers of optoelectronic devices.

The reduced graphene oxide aerogel modified by 4-chlorophenyl sulfoxide was obtained by a simple self-assemble process under the basic reduction-oxide condition, then freeze-dried for future using. The prepared aerogel was shortly named 4CS-rGO, which was characterized by fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, et al. 1 mg of 4CS-rGO composite was used as an adsorbent to adsorb Pd (Ⅱ) and Pt (Ⅳ) in 1.0 mL 4 mM Britton-Robinson buffer solution with various pH. The adsorption efficiency of Pd (Ⅱ) increased with the increase of pH, whereas the hydrolysis of Pd (Ⅱ) happened at pH 13, and the maximum adsorption efficiency of Pd (Ⅱ) was 91.82% at pH 12, which was mainly driven by electrostatic attraction. Besides, the adsorption behavior of the 4CS-rGO composite for Pt (Ⅳ) was explored to evaluate the possibility to isolate Pd (Ⅱ) and Pt (Ⅳ) ions by using aerogel. We found that, quite interestingly, hydrogen bond, hydrophobic interaction and van der Waals force can strongly conquer electrostatic repulsion driven Pt (Ⅳ) ions adsorption behaviour at pH 5, and Pt (Ⅳ) ions displaced by cationic surfactant. Moreover, a tighter Pt (Ⅳ) ions adsorption behaviour than Pd (Ⅱ) ions was observed while we used with/without 4-chlorophenyl sulfoxide modified the graphene to adsorb them respectively. While branched TBAB was easier and more effectively replaced the adsorbed Pt (Ⅳ) ions than strained CTAB.

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