Photo-degradation catalyst screening by high throughput experiments

Abstract

A high throughput fluorescence photo-imaging method has been developed for the screening of photo-degradation catalysts. When employed to analyze the photo-degradation of 1,6-hexamethylenediamine (the probe molecule), the method produced results that are comparable to that when methyl orange was employed as a probe molecule and UV spectrometry as an analysis device. We found that the variation trends in catalytic activity over the same group of catalysts are the same in both cases. The results indicate that the fluorescence photo-imaging method is applicable to the screening of photo-degradation catalysts. For comparison, mesoporous catalysts of high specific surface area prepared by using P123 (HO(CH 2CH 2O) 20(CH 2CH(CH 3)O) 70(CH 2CH 2O) 20H) as a template and “regular” catalysts (those prepared without P123) were tested. The results showed that most of the former catalysts are superior to the latter counterparts. Our study also revealed that the addition of ZrO 2 to TiO 2 did not result in significant improvement in catalytic activities, whereas marked improvement was observed when Nb 2O 5 or WO 3 was added to TiO 2. When Nb 2O 5 and WO 3 were co-doped to TiO 2, the tertiary catalysts exhibited higher catalytic activities. The catalysts containing 20–30% of Nb 2O 5 and 10–20% of WO 3 (balanced with TiO 2) are superior to any of pure TiO 2, Nb 2O 5, WO 3, and the binary catalysts composed of any two of TiO 2, Nb 2O 5, and WO 3. Our study has demonstrated that besides the traditional TiO 2-domain catalysts, active photo-degradation catalysts can be prepared by combination of Nb 2O 5, WO 3, and ZrO 2.