Metal oxide and hydroxide nanoarrays: Hydrothermal synthesis and applications as supercapacitors and nanocatalysts

Transition metal oxides/hydroxides nanoarrays for aqueous electrochemical energy storage systems

“…This method relies on the chemical reactions and solubility changes of substances in a sealed heated aqueous solution above ambient temperature and pressure to grow nanocrystals [19]. The nucleation process on the surface of substrate is quite slow, which avoids the mixed and disorderly arrangement.…”

“…The nucleation process on the surface of substrate is quite slow, which avoids the mixed and disorderly arrangement. The hydrothermal method has many advantages: i) this route is very versatile because the hydrothermal process occurs on a variety of materials, such as Ni(OH) 2 [46], MnO 2 [47], Co(OH) 2 [22,48], FeOOH [49], Cu(OH) 2 [50], ZnO [51], V 2 O 5 [52]; ii) the reaction parameters can be easily controlled including temperature, time and concentration, which would result in different morphologies, porosity and compositions of the final products [19,53] [58]), which offer an even higher porosity and mass-loading of the active layer.…”

“…The 1D nanostructure can offer a direct pathway for electron transfer and the high aspect ratio can facilitate the electrolyte penetration and maximize the utilization of the active materials [19,68].…”

“…Here in this paper we will summarize several fabrication processes of metal oxide and hydroxide materials with nanoarray architectures as well as their applications mainly in aqueous media. As well known, transition metal oxides and hydroxides are considered as the promising materials for next generation aqueous EES devices, owing to their multiple oxidation states that enable rich redox reactions for pseudocapacitance generation [18][19][20], while designing the electrochemically active materials into ordered nanoarrays architectures has been demonstrated effective for achieving higher performance. Thereby we would focus on the recent advances of nanoarray materials as high-performance electrodes for aqueous EES systems including SCs and batteries.…”

Hydrothermal Assisted Synthesis of Hierarchical Nanostructured Metal Oxide Thin Film

“…The technique can be used to synthesize thermodynamically stable and metastable states including novel materials that cannot be easily formed by other synthetic route. The hydrothermal synthesis is carried out in autoclaves which is sealed steel cylinder that can withstand at high temperature and pressure for a long time [6][7][8]. In hydrothermal synthesis materials takes for a longer reaction time.…”