The invention relates to a
supercapacitor in the field of microcapacitors, in particular to a TiO2 / NiO three-dimensional inter-digital
microelectrode and a preparing method of the
microelectrode. According to the preparing method of the
electrode, at first, an insulating layer is oxidized on the surface of a
silicon substrate, then a metallic
titanium layer is sputtered, the micromachining technology is used for preparing a
titanium three-dimensional inter-digital
microelectrode body, the microelectrode body is placed into an HF solution to be oxidized in an anodic mode to form a well-aligned TiO2
nanotube array, NiO is prepared in TiO2 nanotubes through an electrolytic deposition method, and finally the three-dimensional inter-digital microelectrode body with a NiO active material is filled with a KOH
electrolyte. The principle that a TiO2
nanotube material with the high specific surface area and NiO can react in a reversible
redox mode in the KOH
electrolyte is utilized for designing a three-dimensional inter-digital microelectrode structure of a
pseudocapacitance mechanism, and specific
capacitance of a
capacitor is greatly increased compared with a traditional sandwich structure.