Porous 3D flower-like CoAl-LDH nanocomposite with excellent performance for NO₂ detection at room temperature

Abstract

The 3D flower-like CoAl-layered double hydroxide (CoAl-LDH) was successfully prepared using the functional template agent of fluoride ions via a facile one-step hydrothermal route. Various techniques proved that all the samples presented 3D flower-like microstructural morphology. Representatively, the CA-2 sample, which was synthesized with the molar ratio of Co : Al of 3.65 : 1, had considerably abundant pores in its thin nanosheets. The average pore size was 2-4 nm, the specific surface area was equal to 49.45 m 2 g À1 , and the thickness of nanosheets was approximately 3.068 nm. The CA-2 sample showed an excellent response to 0.01-100 ppm NO 2 with ultrafast response/recovery time at room temperature (RT). The detection limit of the sensor even reached 10 ppb. The superior gas sensing performance could be attributed to the synergistic effects of the functional template agent of fluoride ions and specific porous 3D flower-like nanostructure. The current study showed that the 3D flower-like CoAl-LDHs might a promising material in practical detection of NO 2 at RT. Scheme 2 Schematic for the mechanism of NO 2 sensing for CoAl-LDHs. (a) SEM image of 3D flower-like CA-2 on Au electrode; (b and c) the model with response procedure of gas sensing; (d) I-V curve measured for CA-2 sensor in air and 50 ppm NO 2 exposure at RT; (e) IR spectra of CA-2 before and after NO 2 gas detection (CA-2 test NO 2 gas sensing for 2 h).21918 | RSC Adv., 2019,9,[21911][21912][21913][21914][21915][21916][21917][21918][21919][21920][21921] This journal is

Recent Advances in Layered Double Hydroxide-Based Electrochemical and Optical Sensors

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