Electronic equipment Thermoelectric equipment 2 UV-Vis spectrophotometers 2 Anodizations 1 Azo dyes 1 Coatings 1 Copper 1 Copper oxide thin films 1 Different sizes 1 Electrical and optical properties 1 Electrical conductivity 1 Energy gap 1 Field emission microscopes 1 Methyl Orange 1 Nanoporous networks 1 Niobium oxide 1 Optical and electrical properties 1 Optical properties 1 Oxide films 1 Photocatalytic activities 1 Photocatalytic performance 1 Quartz substrate 1 Scanning electron microscopy 1 Sol-gel process 1 Sol-gel technique 1 Sol-gels 1 Solar simulator 1 Spin coating 1 Spin-coating method 1 Thin films 1