4.4 UV-Vis analysis
UV-Vis spectrum of ZCB/r GO, and Taucs’ plot26for the indirect allowed transition of BZC and BZC/r GO composite are presented in Figure 4. Both BZC and BZC/r GO show characteristic absorption in the wavelength region of 200-500 nm. Upon incorporation of r GO, a bathochromic (red) shift in the wavelength region of 300-500 nm was observed. The wavelength maxima of BZC, 381 nm was shifted to 386 nm upon the incorporation of r GO. The optical band gap energy of BZC was 4.6 eV which was increased to 5.2 eV after the addition of r GO. The lower band-gap energy of BZC suggests that the electron can transfer quickly from the valence band to the conduction band compared to BZC/r GO composite.