Synthesis of cu-doped WO3 materials with photonic structures for high performance sensors

Authors

Shenmin Zhu, Shanghai Jiao Tong University, Dongchuan Road, Shanghai
Xinye Liu, Shanghai Jiao Tong University, Shanghai
Zhixin Chen, University of WollongongFollow
Chunjiao Liu, State Key Laboratory of Metal Matrix Composites
Chuanliang Feng, State Key Laboratory of Metal Matrix Composites
Jiajun Gu, Shanghai Jiao Tong Uni
Qinglei Liu, Shanhai Jiao Tong Uni
Di Zhang, Shanghai Jiao Tong University, 800 Dongchuan Road, ShanghaiFollow

RIS ID

34022

Publication Details

Zhu, S., Liu, X., Chen, Z., Liu, C., Feng, C., Gu, J., Liu, Q. & Zhang, D. (2010). Synthesis of Cu-doped WO₃ materials with photonic structures for high performance sensors. Journal of Materials Chemistry, 20 (41), 9126-9132.

Abstract

Cu-doped photonic crystal (PC) WO₃ replicas from Morpho butterfly wings have been prepared by using a combined sol–gel templating and calcination method. The exact replications in the Cu-doped PC WO₃ replicas at the micro- and nanoscales were confirmed by scanning electronic microscopy (SEM) and transmission electron microscopy (TEM). A combination of X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Raman and X-ray photoelectron spectra (XPS) measurements revealed that copper does not form clusters, but is randomly distributed inside the WO₃ matrix lattice. The optical properties of the Cu-doped PC WO₃ replica as well as the Morpho butterfly wing template were investigated by using reflectance spectroscopy, and it was found that the reflected light chromaticity of the Cu-doped PC WO₃ replica was inherited from the PC Morpho butterfly wings. Cu-doped WO₃ replicas without photonic crystal structures (Cu-W replica) were also fabricated in the same way as the Cu-doped PC WO₃ replica but using Euploea mulciber butterfly wings as the template. Chemical sensors fabricated from the Cu-doped PC WO₃ as well as the non-PC Cu-doped WO₃ replicas were tested for a range of gases: (CH₃)₃N (TMA), NH₃, C₂H₅OH, HCHO, CH₃OH, acetone, H₂, CO and NO₂ and they showed a high selectivity for TMA. The sensitivity of the Cu-doped PC WO₃ replica sensors can reach up to 2.0 for a trimethylamine concentration as low as 0.5 ppm at 290 °C. The high sensitivity of the Cu-doped WO₃ replica sensors to TMA is attributed to the catalytic effect of Cu on the reaction between the testing gas and the oxide surface. Furthermore, the Cu-doped PC WO₃ replica sensor is twice as sensitive as the Cu-doped non-PC WO₃ replica to trimethylamine. This may be explained by the photonic crystal structure of the Cu-doped PC WO₃.