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The hybrid sol–gel coatings on AA2024-T3 were prepared with a silane coupling agent 3-glycidoxypropyltrimethoxysilane (GPTMS) and a metal alkoxide tetra-n-propoxyzirconium (TPOZ) as precursors. The effect of acetylacetone (AcAc) as a chelating agent on the corrosion protection properties of sol–gel coatings were evaluated and the optimal AcAc/TPOZ molar ratio was obtained. The sol–gel coatings were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The corrosion protection properties of the coatings were evaluated by means of potentiodynamic polarization study (PDS) and electrochemical impedance spectroscopy (EIS). It is demonstrated that AcAc avoids fast hydrolysis of TPOZ and benefits to form stable sols. The coating with AcAc/TPOZ molar ratio of 3 shows the best corrosion protection performance in 0.05 M NaCl solution. [ABSTRACT FROM AUTHOR]

Abstract: Molecular dynamic simulation was applied in analyzing the difference of surface damage during the impact of a large silica cluster on a crystal silicon substrate in dry and wet condition, respectively. The simulation results show that the damage of silicon substrate under the dry impact is more severe than that under the wet impact. A reason is that the water film buffers the impact of the incident cluster at the init stage under the wet impact. The more important reason is that the water film might be solidified into a continuous thin film at the cluster deformation stage. So, the considerable great impact energy of the cluster will be absorbed by the water film and transformed into thermal dissipation of energy between the simulation ensemble and the water film. [Copyright &y& Elsevier]

[Display omitted] • A novel core–shell-like heterostructure constructed by Co 3 S 4 -embedded in carbon-encapsulated BaRuO 3 (BaRuO 3 @CS- x) was fabricated. • The HER activity of BaRuO 3 @CS-0.1 is superior to that of Pt/C. • The intermetallic charge transfer between the Co of Co 3 S 4 and the Ru of BaRuO 3 is responsible for the enhanced HER activity. Constructing and manipulating heterostructure is an effective strategy to prepare electrocatalysts with excellent performance for water electrolysis. Herein, an efficient alkaline hydrogen evolution reaction (HER) electrocatalysts, Co 3 S 4 -embedded in carbon-encapsulated BaRuO 3 (BaRuO 3 @CS-0.1), was synthesized through the sacrificial template method of ZIF-67 encapsulated BaRuO 3 precursors. By inheriting the exceptional merits of different ingredients, this heterostructure catalyst BaRuO 3 @CS-0.1 enables intermetallic charge transfer between Ru and Co with boosted HER kinetics, and thus displaying higher catalytic activity towards HER, as evidenced by the intensively theoretical calculations and experimental measurements. BaRuO 3 @CS-0.1 exhibits excellent HER performance, with the lowered overpotentials of 26 mV to achieve 10 mA cm−2 in comparison to the pristine BaRuO 3 (51 mV), which is also superior to Pt/C catalyst at large current density. Moreover, this heterostructure also demonstrates comparable oxygen evolution reaction (OER) activities with the representative electrocatalysts, delivering current densities of 10 mA cm−2 at a potential of 1.546 V for overall water splitting. These findings provide a rational route to optimize the performance of bulk electrocatalysts and endow them with richer electrochemical activity through this composite strategy. [ABSTRACT FROM AUTHOR]

Highlights: [•] The impact of clusters on Si substrates covered by oxide films was studied by MD. [•] The optimal oxide film for the maximum of the number of atoms removed would occur. [•] The optimal oxide film is a continuous monolayer molecular structure. [•] The optimal oxide film is due to the combined effects of adhesion and penetration. [•] The contact–penetration–adhesion material removal process occurs during CMP process. [Copyright &y& Elsevier]

Abstract: Molecular dynamics (MD) simulation is applied in analyzing the material removal mechanism of silicon substrate under the impact of large porous silica cluster with different pore diameters. With the increasing of the pore diameter of the porous cluster, the number of the atoms removed from the impact silicon surface will firstly increase and then decrease until the cluster is adhered to the substrate, which is due to the combinational effects of plough of the cluster, adhesion between the cluster and the substrate, and permeation of the substrate atoms through the pore of the cluster. And adhesion is the most significant one among these three effects. Meanwhile, the damage of the impact substrate will become weaker due to the decreasing of the penetration depth with the increasing of the pore diameter. In addition, it is found that the effect of an enlarged real contact area between the cluster and the substrate is more significant than that of deeper penetration of the cluster in order to enhance the material removal rate (MRR) during the impact process. These findings are instructive in optimizing the process parameters to obtain lower surface roughness and higher material removal rate during the chemical mechanical polishing process. [Copyright &y& Elsevier]