AgCl-based selective laser melting photocatalytic module for degradation of azo dye and E. coli

An innovative 3D printing procedure for producing a highly porous AgCl/Ag-0 photocatalyst was developed and tested for its stability and degradability of azo dye (Orange II) and bacteria (Escherichia coli). The AgCl/Ag-0 photocatalytic module was fabricated through selective laser melting (SLM), in which the AgCl powder was stacked in a thin layer (approximate average thickness of 30 mu m) on a platform and melted by a high-power laser beam layer by layer until the 3D module was created. The melting process may cause AgCl to transform into other compounds, which may, in turn, reduce the activity of photocatalysts; for this reason, the optimal laser power and scanning speed for constructing an SLM module were investigated; they were determined to be 26 W and at 385 mm/s. This photocatalytic module effectively degraded azo dye and sterilized E. coli. The degradation of azo dye was performed under visible and UV light irradiation, and the degradation kinetics was first-order reactions. Furthermore, the azo dye degradability (95%) of this photocatalyst module persisted for five cycles in our experiment. The sterilization of E. coli was accomplished within a 135-min test, and the degradation kinetics was also first-order reactions. The photocatalytic module fabricated through SLM not only exhibited the ability to degrade contaminants in the water but also had durability and reliability after repeated use.

Automated summary

The innovative 3D printing procedure developed an AgCl/Ag-0 photocatalytic module through selective laser melting, which effectively degraded azo dye and sterilized E. coli. The optimal laser power and scanning speed for constructing the module were determined to be 26 W and 385 mm/s. The degradation kinetics of both azo dye and E. coli were first-order reactions, and the photocatalytic module exhibited durability and reliability even after multiple cycles of use.