In recent years, a variety of research has focused on the impact of creep on operating cross-fault diversion tunnels. Specifically, the creep effect on the cross-fault diversion tunnels is particularly significant. Time-dependent deformation of surrounding rocks during construction and service directly affects the structural safety of hydraulic tunnels.
Whereas N-TiO 2 was more photoactive than commercial undoped TiO 2, the introduction of nitrogen in ZnO wurtzite resulted in a drastic reduction in photocatalytic activity, with only 45% EBT discoloration compared to total color removal obtained with the commercial ZnO sample, suggesting intrinsic limitations for doping of this class of semiconductors. Different behavior was observed under UV irradiation. Both N-doped semiconductors evidenced an improvement in photocatalytic activity under visible light irradiation (62% and 20% EBT discoloration for N-TiO 2 and N-ZnO, respectively) in comparison with the undoped samples, which were inactive in the presence of visible light. The photocatalysts were tested for the degradation of Eriochrome Black T (EBT), which was selected as a model azo dye. Compared to undoped samples, the introduction of nitrogen in the semiconductor lattice resulted in a shift of band-gap energy to a lower value: 3.0 eV for N-ZnO and 2.35 eV for N-TiO 2. The chemico-physical characteristics of synthesized samples were studied by Raman spectroscopy, X-ray diffraction, SEM analysis, N 2 adsorption–desorption at −196 ☌, and diffuse reflectance spectroscopy. N-doped TiO 2 (N-TiO 2) and N-doped ZnO (N-ZnO) were synthesized utilizing ammonia as a dopant source.
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