Extending the light transmission in the continuous flow photocatalytic process by 3D printed silica packing

One of the most important limitations to the development of photocatalytic process is the light damping in the reaction medium, as described by the Beer-Lambert Law. To address this issue, we developed a new approach by 3D printing the silica glasses to extend the light transmission. We first compared and selected the photosensitive components, and then regulated the debinding and sintering procedure based on the thermogravimetry data. The 3D printed transparent silica cylinders were used as catalyst carriers in a packed bed micro photocatalytic reactor (MPR) for the methylene blue degradation. We also studied the catalyst support using opaque Al 2 O 3 , and a catalyst suspension system for comparison. The results indicated that the use of printed silica as carriers significantly enhanced the reaction efficiency of the MPR. The once-coated MPR demonstrated a remarkable degradation efficiency of 91.4 % with a short residence time of just 9.7 s. This improvement was attributed to the high transparency of silica, which extended the permeation of UV light within the system. Finally, we investigated the scale up effect, which demonstrated that size effects and mass transfer played crucial roles in the MPR.