Environmental Remediation Materials Unit, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
J Am Chem Soc. 2012 Feb 1;134(4):1974-7. doi: 10.1021/ja210610h. Epub 2012 Jan 20.
A strategy of reaction-environment modulation was employed to change the surface property of a semiconductor photocatalyst to enhance its photocatalytic performance. Surface alkalinization induced by a high alkalinity of the solution environment significantly shifted the surface energy band of a SrTiO(3) photocatalyst to a more negative level, supplying a strong potential for H(2)O reduction and consequently promoting the photocatalytic efficiency of H(2) evolution. This mechanism is also applicable for visible-light-sensitive La,Cr-codoped SrTiO(3) photocatalyst, which hence, could achieve a high apparent quantum efficiency of 25.6% for H(2) evolution in CH(3)OH aqueous solution containing 5 M NaOH at an incident wavelength of 425 ± 12 nm.
采用反应-环境调控策略改变半导体光催化剂的表面性质，以提高其光催化性能。溶液环境的高碱性诱导的表面堿化作用显著将 SrTiO(3)光催化剂的表面能带移至更负的水平，为 H(2)O 还原提供了强大的动力，从而促进了 H(2)释放的光催化效率。这种机制也适用于可见光敏感的 La、Cr 共掺杂 SrTiO(3)光催化剂，因此，在 425 ± 12nm 的入射波长下，在含有 5MNaOH 的 CH(3)OH 水溶液中，光解水制氢的表观量子效率可高达 25.6%。
