Development of highly visible-light-sensitive photocatalysts withsurface nanostructure controlled by cold plasma

利用等离子体-表面相互作用控制表面纳米结构的形成，开发了高可见光敏感的光催化剂，具体如下：（1）在TiO_2和过渡金属掺杂的TiO_2表面分别形成氮掺杂的表面层。很明显，它们的带隙随着表面层的形成而变窄。(2)采用等离子体化学气相沉积法在TiO_2表面形成含Cu层。等离子体CVD处理后的TiO_2可以实现多电子反应，其中的Cu被可见光激发电子还原。(3)以Nb掺杂的TiO_2为n型半导体，表面层掺杂氮，CuBi_2O_4为p型半导体的复合材料表现出Z型机制，即在半导体中每次可见光激发后，可见光激发的电子可以从n型半导体转移到p型半导体。

Highly visible-light-sensitive photocatalysts are developed with the formation of surface nanostructures controlled by plasma-surface interaction, as follows : (1) Nitrogen-doped surface layer are formed on surfaces of TiO_2 and transition metal-doped TiO_2, respectively. It becomes apparent that their band-gaps become narrow with the formation of the surface layer. (2) Cu-contained layer is formed on a surface of TiO_2 with plasma CVD using organometallic compound. Multi-electron-reactivity of the plasma CVD-treated TiO_2 can realize with the contained Cu reduced by visible-light-excited electrons. (3) Composite composed of Nb-doped TiO_2 as n-type semiconductor having nitrogen-doped surface layer and CuBi_2O_4 as p-type semiconductor shows Z-scheme mechanism in which visible-light-excited electron can be transferred form the n-type to the p-type semiconductor after each visible-light excitation in the semiconductors.