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An oxalate-pyrolysis method was proposed for the fabrication of an integral Co3O4 catalyst towards PMS activation to degrade MB.

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For the purpose of endowing TiNb alloy with antibacterial function, a two-step strategy was proposed to fabricate Ag-incorporated TiO2 film on TiNb substrate in this study. X-ray diffraction (XRD), Field-emission scanning electron microscopy (FESEM) and X-ray photoelectron microscopy (XPS) were used to characterize the crystal phases, morphologies and chemical compositions of the samples. The results showed that a layer of anatase TiO2 film with two kinds of morphologies was formed by hydrothermal treatment of TiNb alloy in NH4F-H2O2 solution. When the as-obtained TiNb-based TiO2 film was subjected to a further ultraviolet light irradiation in AgNO3 solution, metallic Ag granules with size range from 60 nm to 1.3 μm were uniformly deposited on the surface of TiO2 particles. Escherichia coli (E. coli) was selected as a model to estimate the bacteriostatic effect of the Ag-TiO2 film. The experimental result indicated that Ag-incorporated TiO2 exhibited excellent antibacterial activity against E. coli. It suggests that this two-step method for preparation of Ag-TiO2 composite film may provide an alternative strategy to reduce bacterial infection for Ti-implants in clinical application.

In this work, hierarchical flower-like CoOOH assembled from many nanoflakes with a thickness of 20 nm was fabricated by a simple chemical bath deposition (CBD) method, and its performance as a heterogenous catalyst to activate peroxymonosulfate (PMS) for degradation of methylene blue (MB) solution was explored. The results show that CoOOH/PMS is a high efficient system for MB removal, in which 91.95% degradation of MB can be realized within 25 min. Influences of process parameters, including dosage of PMS, addition of catalyst, and co-existed anions on MB degradation were also investigated. It is found that the degradation rate of MB increases with the increase of the amount of PMS from 0.15 mmol·L-1 to 0.45 mmol·L-1. In such PMS concentrations ranges, CoOOH catalyst amount of 0.03 g·L-1 is adequate for PMS activation in the reaction system. The presence of Cl-1and HCO3- anions has a negative effect on MB degradation, while SO42- has no significant influence. In addition, quenching experiments were conducted and SO4 ·- is confirmed as the main active specie during the MB degradation process. Moreover, cycling runs proven that CoOOH could be re-used to activate PMS for MB degradation without notable activity reduction. These results suggest that hierarchical CoOOH is a promising PMS activator for organic pollutant removal.