Influence of Cu distribution on photocatalytic activity of Cu-doped titania prepared using metal alkoxides

Photocatalytic activity of Cu-doped titania prepared by controlling the Cu distribution

“…The Cu-TiO 2 prepared by adding the Cu after the longer reaction period of TTIP, i.e., P-Cu-2 and especially P-Cu-3, clearly exhibited a much faster reaction rate, i.e., higher activity. 12) The Cu-TiO 2 prepared by adding the Cu before the TTIP reaction and after the shorter reaction period of TTIP, i.e., P-Cu-1 and P-Cu-2, demonstrated lower performances due to formation of the oxygen defects and Cu + species. With respect to the Cu content, 0.070.09 mol % Cu and 0.11 mol % Cu were the most effective amount for P-Cu-1 and P-Cu-3 and for P-Cu-2, Fig.…”

“…11),12) This is significantly enhanced on the particle surface whereas the charges are delocalized in the bulk. 12)…”

“…On the other hand, the titania prepared by adding copper alkoxide after some reaction period of titanium alkoxide demonstrated a higher performance than that prepared by initially mixing the copper and titanium alkoxides. 12) This result indicated that the high Cu localization on only the titania surface rather than the high dispersion inside the titania bulk increased its photocatalytic function. Therefore, the copper and titanium ions should not be necessarily homogeneously mixed for the high photocatalytic performance.…”

“…This interaction is influenced by the Cu distribution in the titania nanoparticle due to structural factors such as accessibility and interactivity of the reactants. 12) However, the Cu distribution at an atomic level is difficult to be visually observed by general analyses because the amount of the effective Cu is very low, i.e., much less than 1 mol % versus the Ti amount. 11), 12) In our previous study, Cu-doped titania (Cu-TiO 2 ) was prepared by the refluxing of a homogeneous mixture of copper and titanium alkoxides.…”

“…12) However, the Cu distribution at an atomic level is difficult to be visually observed by general analyses because the amount of the effective Cu is very low, i.e., much less than 1 mol % versus the Ti amount. 11), 12) In our previous study, Cu-doped titania (Cu-TiO 2 ) was prepared by the refluxing of a homogeneous mixture of copper and titanium alkoxides. 11),12) The refluxing improved the Cu 2+ dispersion in the titania and formed effective Ti-O-Cu bonds, which induced the electronic interaction between the Ti and Cu.…”