Degradation of Metronidazole from Aqueous Environment Using Hydrothermally Synthesized ZnO, N-Doped ZnO, and ZnO/AC Nanoparticles

Table 4

Optical band gaps.

Complexes	Direct band gap (eV)
ZnO	2.8
ZnO (400°C)	2.7
N-ZnO	2.7
ZnO/AC	4.1