Physics Department and Nanotechnology Research Center, National Dong Hwa University, Hualien, Taiwan 97401.
J Am Chem Soc. 2010 Aug 18;132(32):10982-3. doi: 10.1021/ja909901f.
Rutile TiO(2) nanoparticles with new sites for effectively trapping photogenerated holes have been prepared by reacting the TiO(2) nanoparticles prepared in hydrogen atmosphere with molecular oxygen at elevated temperatures. The observed g values and the occurrence of (47)Ti and (49)Ti octet hyperfine pattern allowed us to assign this EPR active center to surface oxygen centered anion radical with two coordinating titaniums. The effective trapping of photogenerated holes by these new sites inhibits the electron-hole recombination and results in an enhanced photocatalytic activity under visible light by a factor of 2.5 compared with samples prepared parallel in air. Oxidation of reduced TiO(2) apparently is a simple low-cost and promising route for improving the photoactivity of TiO(2).
锐钛矿型 TiO(2) 纳米粒子具有新的捕获光生空穴的活性位，通过在高温下将在氢气气氛中制备的 TiO(2) 纳米粒子与氧气反应制得。观察到的 g 值和 (47)Ti 和 (49)Ti 八重超精细图案的出现，使我们能够将这个 EPR 活性中心分配给表面氧中心阴离子自由基，其中有两个配位钛。这些新的活性位能够有效地捕获光生空穴，抑制电子-空穴复合，使得在可见光下的光催化活性提高了 2.5 倍，与在空气中平行制备的样品相比。显然，氧化还原 TiO(2) 是一种简单、低成本、有前途的提高 TiO(2) 光活性的方法。
