2. Experimental Section
2.1 Materials
All chemicals can be used directly
without any further purification any more. Al nanoparticles (Al NPs)
(~100nm diameter) are purchased from Shanghai Nai-ou
Nano Technology Co., LTD, and the thickness of alumina shell on the
surface of Al NPs is about 5 nm, so the active aluminum content is about
64.5%. Potassium hypermanganate (KMnO4)
(>99.5%) and concentrated hydrochloric acid (HCl)
(36.0%~38.0%) are supplied by Shanghai Lingfeng
Chemical Reagent Co., LTD for further MnO2 synthesis.
MnO2 nanorods (MnO2 NRs) are synthesized
via hydrothermal method at 140 oC for 12 h, please see
Ref.[26-27]. Poly(VDF- ter- HFP-ter - TFE)
terpolymer
is selected from Shanghai 3F New Chemical Materials Co., LTD, with about
67.5% fluorine content. As for solvents and dispersant, ethyl alcohol,
deionized water and dimethylformamide (DMF) are purchased from Nanjing
Chemical Reagent Co., LTD.
2.2 Sample Preparation
The ratio of each component is
listed in Table 1. In a typical preparation experiment, the mixture of
Al NPs and MnO2 NRs is dispersed in ethyl alcohol by
using ultrasonic method. In the meanwhile, the corresponding poly(VDF-
ter- HFP-ter - TFE) terpolymer component is dissolved by DMF. Then, the
terpolymer -DMF solution is poured into the mixture of Al NPs and
MnO2 NRs as the precursor for further electrospray
method. The diagram of electrospray experiment is shown in Figure 1. The
precursor is put into the syringe with a 0.43 mm flat nozzle. The
distance between the end of nozzle and the receiving plate is about 10
cm, and there is a 14 kV DC voltage loaded onto the distance. The
precursor is ejected by a syringe pump with the velocity of 4.0 mL
h-1. During the process, the solvent volatilized and
solid-state samples attach to the receiving plate. Finally, the samples
are gently scraped off from the receiving plate for further tests.
Table 1 The detailed ratio of each component