“…In 2 O 3 as a transparent conductive oxide has recently drawn attention because of a wide band gap (2.9–3.75 eV), a high electrical conductivity, high optical transmittance, and excellent luminescence . Such versatility enables In 2 O 3 to be used in various applications such as solar cells, anti-reflection coating, gas sensors, thin-film transistors, lithium ion batteries, optoelectronics , devices, and supercapacitors. − As for the supercapacitor application, a large number of In 2 O 3 nanostructures were investigated, including In 2 O 3 -based nanorods , and nanospheres, In 2 O 3 -nanowires/carbon nanotubes or macroporous carbon or mesoporous carbon or reduced graphene oxide, hierarchical NiO–In 2 O 3 microflowers (3-D)/nanorods (1-D), and other In 2 O 3 nanowires (i.e., nanotowers, nanocones, or nanobouquets) . However, these In 2 O 3 nanostructures with different morphologies are usually prepared by potentiodynamic deposition, chemical vapor deposition (CVD), pulsed laser deposition, thermal decomposition, and hydrothermal method. ,− Meanwhile, these In 2 O 3 nanostructures were reported to be fabricated on carbon materials, planar silicon substrates, or metal collectors.…”