Search

To improve light usage, Ag and Cu were co-impregnated with nano-ZnO, and the mesoporous silica gel (meso-SiO2) was chosen as the carrier. The sol-gel method was used to successfully construct a composite photocatalyst with 3 percent Ag/0.1 percent Cu/nano-ZnO/meso-SiO2. For the evaluation of the photocatalytic activity of the as-prepared catalysts, Reactive Black 5 was used as a simulated organic pollutant in aqueous. The results revealed that uniform spherical nano-ZnO particles with a diameter of 10 nm were attached to the surface and mesopore of meso-SiO2. The average pore width and specific surface area of this composite were 7.06 nm and 305 m2.g-1, respectively. The optimal amount of loaded Ag and Cu were 3% and 0.1%, respectively, which resulted in around 100% removal of Reactive Black 5 after 280 min UV-light irradiation. The degradation process followed pseudo-first-order kinetics. Ag and Cu-loaded nano-ZnO/SiO2 could be advantageous for suppressing the recombination of photo-generated holes and electrons, thus improving the degradation efficiency. The constant of degradation rate and adsorption equilibrium of 3%Ag/0.1%Cu/nano-ZnO/meso-SiO2 were 0.049 min–1 and 2.14 L.g-1, respectively. After three reuses, the Ag/Cu/ZnO/meso-SiO2 photocatalyst remained very stable during the photocatalytic process with no loss of photocatalytic activity. According to the GC-MS results, a probable degradation mechanism was estimated.

In order to study the progressive collapse resistance of the panel-rod composite latticed shell, a static test was performed on two latticed shells with the same size, one of which was removed a key member. The results of experiments and numerical simulations show that the composite reticulated shells were damaged due to the fracture of some members and the shearing of some rivets. Compared with the complete latticed shell, the bearing capacity of the latticed shell which was removed a key member did not decrease too much, but its displacement of the joints increased significantly. The phenomenon indicated that the removal of the key member had a certain effect on the progressive collapse resistance of the composite latticed shell. The key members of the composite latticed shell must be locally strengthened.