Temperature-controlled electrochemical switch based on layered double hydroxide/poly(N-isopropylacrylamide) ultrathin films fabricated via layer-by-layer assembly.
In this paper we report the fabrication of layered double hydroxide (LDH) nanoparticles/poly(N-isopropylacrylamide) (pNIPAM) ultrathin films (UTFs) via the layer-by-layer assembly technique, and their switchable electrocatalytic performance in response to temperature stimuli was demonstrated. X-ray diffraction and UV-vis absorption spectroscopy indicate a periodic layered structure with uniform and regular growth of the (LDH/pNIPAM)(n) UTFs; an interaction based on hydrogen bonding between LDH nanoparticles and pNIPAM was confirmed by X-ray-photoelectron spectroscopy and Fourier transform infrared spectroscopy. Temperature-triggered cyclic voltammetry and electrochemical impedance spectroscopy switch for the UTFs was obtained between 20 and 40 °C, accompanied by reversible changes in surface topography and film thickness revealed by atomic force microscopy and ellipsometry, respectively. The electrochemical on-off property of the temperature-controlled (LDH/pNIPAM)(n) UTFs originates from the contraction-expansion configuration of pNIPAM with low-high electrochemical impedance. In addition, a switchable electrocatalytic behavior of the (LDH/pNIPAM)(n) UTFs toward the oxidation of glucose was observed, resulting from the temperature-controlled charge transfer rate. Therefore, this work provides a facile approach for the design and fabrication of a well-ordered command interface with a temperature-sensitive property, which can be potentially applied in electrochemical sensors and switching.
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
Yibo
Y
Dou
Jingbin
J
Han
Tengli
T
Wang
Min
M
Wei
David G
DG
Evans
Xue
X
Duan
D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D002384:Catalysis; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D017971:Tin Compounds / Q000737:chemistry
D000178:Acrylamides; D000180:Acrylic Resins; D006878:Hydroxides; D011108:Polymers; D017971:Tin Compounds; C052970:poly-N-isopropylacrylamide; C109984:indium tin oxide