Fabrication of mesoporous nickel pyrophosphate electrodes and their transformation to nickel hydroxide with decent capacitance in alkaline media
The development of high-energy-density electrodes is paramount for the advancement of renewable and clean energy storage materials. In this study, we have devised a synthetic approach to fabricate mesoporous Ni 2 P 2 O 7 ( m -NiPP) electrodes with a decent charge capacity. The method involves the fo...
Gespeichert in:
Veröffentlicht in: | Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2023-10, Vol.11 (41), p.22384-22395 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The development of high-energy-density electrodes is paramount for the advancement of renewable and clean energy storage materials. In this study, we have devised a synthetic approach to fabricate mesoporous Ni
2
P
2
O
7
(
m
-NiPP) electrodes with a decent charge capacity. The method involves the formation of a liquid crystalline mesophase from an aqueous solution containing nickel nitrate hexahydrate salt (Ni(
ii
)), pyrophosphoric acid (PPA), and a non-ionic surfactant (P123). The mesophase solidifies through the polymerization of Ni(
ii
) ions and PPA, ultimately forming a mesostructured Ni
2
H
x
P
2
O
7
(NO
3
)
x
·
n
H
2
O semi-solid, which can be subsequently calcined to yield mesoporous Ni
2
P
2
O
7
(
m
-NiPP). The gelation and polymerization process can be monitored using gravimetric, ATR-FTIR, XRD, and POM techniques as water evaporates during the transformation. The results reveal that the reaction between the Ni(
ii
) ion and PPA initiates in the solution phase, continues in the gel phase, and concludes upon gentle heating. The same clear aqueous solution can be coated onto a substrate, such as FTO or graphite rods, and then calcined at various temperatures to produce the
m
-NiPP electrodes, composed of spherical mesoporous NiPP particles. These electrodes remain amorphous over a wide temperature range, but crystallize at approximately 700 °C while retaining their porous structure. However, when exposed to a 3 M KOH solution, the spherical
m
-NiPP particles undergo a transformation into β-Ni(OH)
2
particles. These transformed particles are approximately 1.5 nm thick, equivalent to 3-4 layers, and 7 nm wide, all while maintaining their spherical morphology. This transformation process occurs rapidly for amorphous
m
-NiPP and proceeds more slowly in the case of crystalline
m
-NiPP. The resulting electrodes exhibit a substantial charge capacity of 422 C g
−1
and an impressive specific capacitance of over 1407 F g
−1
.
A novel synthesis method has been devised to create mesoporous nickel pyrophosphate coated graphite electrodes, which undergo a chemical conversion into nickel hydroxide nanoflakes with a notable charge capacity in alkaline media. |
---|---|
ISSN: | 2050-7488 2050-7496 |
DOI: | 10.1039/d3ta05578g |