posted on 2023-10-23, 16:33authored byYanqing Wei, Yize Zhao, Yue Liu, Na Luo, Zunchang Gao, Pu Hou, Yang Liu, Yanhua Zhang, Pengfei Huo
Nanochannel ionic diodes require extremely complex and
expensive
fabrication processes. Polyelectrolyte ionic diodes attracted widespread
attention among ionic rectification systems due to their simplicity
of development and the ability to break the size limits of the nanochannel.
However, enhancement of their rectification ratio is still in the
exploratory stage. In this study, chitosan (CS) hydrogels and sodium
polyacrylate (PAAs) hydrogels were prepared as the substrates for
the heterostructured ionic diodes. 5,10,15,20-Tetrakis(4-aminophenyl)-21H,23H-porphyrin
(TAPP) was selected to regulate the rectification ratio of ionic diodes.
By adding 0.05 wt % TAPP to the CS hydrogel, the rectification ratio
of the ionic diode can be increased to 10, which is 4 times larger
than that of the undoped ionic diode. In contrast, the rectification
ratio of the ionic diodes with TAPP added in the PAAs hydrogel decreases
to 2. In addition, the ionic diode composed of the TAPP-doped CS hydrogel
and PAAs hydrogel has the characteristics of a high open-circuit voltage.
The open-circuit voltage of the 10 mm × 10 mm × 4 mm heterojunction
hydrogel reached 370 mV. The ionic diodes can be used as a self-powered
power supply device.