Fabrication of 3D biomimetic composite coating with broadband antireflection, superhydrophilicity, and double p-n heterojunctions
biomimetic composite coating, broadband antireflection, superhydrophilicity, double p-n heterojunctions
ABSTRACT 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.
Tsinghua University Press
Gang Shi,Xin Zhang,Jianhua Li,Haiyan Zhu,Ying Li,Liping Zhang,Caihua Ni,Lifeng Chi, Fabrication of 3D biomimetic composite coating with broadband antireflection, superhydrophilicity, and double p-n heterojunctions. NanoRes.2017, 10(7): 2377–2385