Research Institute of Photocatalysis, State Key Laboratory Breeding Base of Photocatalysis, Fuzhou University, Fuzhou 350002, People's Republic of China.
ACS Appl Mater Interfaces. 2012 Apr;4(4):2273-9. doi: 10.1021/am300272f. Epub 2012 Apr 12.
Different pathways for the degradation of rhodamine (RhB) as well as different activity order for the degradation of RhB and methyl orange (MO) were observed over hexagonal ZnIn(2)S(4) microspheres and cubic ZnIn(2)S(4) nanoparticles. A detailed study of the physicochemical and surface properties of these two ZnIn(2)S(4) polymorphs has been carried out to elucidate these phenomena. The results reveal that hexagonal ZnIn(2)S(4) microspheres are composed of nanolamella petals growing in the ab plane, i.e., the negative (0001) S plane. This negative (0001) S plane not only is favorable for the adsorption of the cationic dye RhB via -N(Et)(2) groups but also can accumulate the photogenerated holes. These make the hole-directed photocatalytic de-ethylation of RhB more expedient over hexagonal ZnIn(2)S(4) microspheres. This negative (0001) S plane of hexagonal ZnIn(2)S(4) microspheres also shows promoting effect for the degradation of cationic dye like MB, but not for the degradation of anionic dye like MO. Our result provides some new insights in how the surface facet can take effect on influencing the performance of a photocatalyst and why different polymorphs can exhibit different photocatalytic performance.
在六方相和立方相的 ZnIn2S4 微球和纳米粒子上，观察到罗丹明（RhB）的降解途径不同，以及 RhB 和甲基橙（MO）的降解活性顺序不同。对这两种 ZnIn2S4 多晶型物的物理化学和表面性质进行了详细研究，以阐明这些现象。结果表明，六方相 ZnIn2S4 微球由在 ab 平面上生长的纳米薄片花瓣组成，即负（0001）S 平面。这个负（0001）S 平面不仅有利于阳离子染料 RhB 通过 -N(Et)(2)基团的吸附，而且可以积累光生空穴。这使得空穴定向的 RhB 的光催化去乙基反应在六方相 ZnIn2S4 微球上更加便捷。六方相 ZnIn2S4 微球的这个负（0001）S 平面也对阳离子染料如 MB 的降解表现出促进作用，但对阴离子染料如 MO 的降解没有促进作用。我们的结果为表面晶面如何影响光催化剂的性能以及为什么不同的多晶型物表现出不同的光催化性能提供了一些新的见解。
