Fabrication of 3D biomimetic composite coating with broadband antireflection,superhydrophilicity, and double p-n heterojunctions

The traditional single material with two-dimensional (2D) biomimetic moth-eye structures is limited by its narrowband antireflection and single functional capability.To overcome these disadvantages,we exploited wet etching and hydrothermal synthesis coupled with chemical oxidation for fabricating a threedimensional (3D) biomimetic moth-eye coating with ternary materials (polypyrrole nanoparticles,TiO2 nanorods,and Si micropyramids,i.e.,PPy/TiO2/Si-p).This coating reduced the reflectivity to ＜4％ at wavelengths ranging from 200 to 2,300 nm and exhibited remarkable superhydrophilicity with a low water contact angle of 1.8°.Moreover,the composite coating had double p-n heterojunctions,allowing the high-efficiency separation of photogenerated carriers.The photocurrent density of PPy/TiO2/Si-p was more than three times higher than that of TiO2/Si-p at a positive potential of 1.5 V.The proposed method provides a means to enhance solar energy conversion.     

Study on the microstructures,electrical resistance and mechanical properties of sputtering chromium target by HP,HIP and canning–HIP processes

In recent years, pure chromium (Cr) targets have been commonly used in metal surface coating treatment and flat-panel displays. In the traditional production of a pure Cr-target, there is a greater use of casting methods; however, the metal ingot frequently suffers from ingredient segregation, porosity and non-uniform microstructure defects. Powder metallurgy (PM) is a good method for fabricating high melting materials with better microstructure and properties. This study produced Cr targets using hot pressing (HP), hot isostatic pressing (HIP) and canning–HIP of PM technology. The experimental results showed that the Cr targets made by HP–HIP can further improve the density and mechanical properties. The relative density increases from 98.8% to 99.3%. Canning–HIP of the Cr target, in particular, can provide smaller grain size (50 μm), lower porosity about 0.3%, and increased relative density to 99.7%, with a TRS of up to 58 MPa. The canning–HIP process also shows the optimal electrical resistivity (8.003 × 10^− 5 Ω-cm), which suits for applications in the sputtering process.     

ATP/ZnO纳米复合材料的制备及其对亚甲基蓝吸附性能的影响

以硫酸锌和碳酸铵为原料,采用化学沉淀法在凹凸棒土(ATP)的表面负载纳米氧化锌,合成了ATP/ZnO纳米复合材料,以吸附亚甲基蓝为模型反应,研究了加料方式、氧化锌负载量、反应温度、煅烧温度和煅烧时间等制备条件对复合材料吸附性能的影响.结果表明:当采用碳酸铵溶液滴加到ATP浆料和硫酸锌混合液、氧化锌负载量为m(ZnO):m(ATP)=1:5、煅烧温度500℃、煅烧时间2h、反应温度为60℃时制备的复合材料吸附性能较好,对亚甲基蓝的去除率达到95.5%.