Fabrication of homogeneously distributed (HD) macropores by breath figure process is an active research area. Adopting the process, for the first time, we report the fabrication of HD macro with nested meso (hierarchical) porous nanocrystalline zinc indium oxide conducting sol-gel thin film on glass by dip-coating at 45-50% room relative humidity (RH) from a solution in ethanol-2-butanol (1:1, w/w) medium with a 1:1, Zn:In ratio. In this process, solution composition and RH are found to play key roles on HD macropore generation. The film is highly promising toward visible-light-driven photoelectrochemical water splitting.
Keywords: breath figure process; hierarchical porous film; photoelectrochemical activity; sol−gel; zinc indium oxide.