Location and State of Pt in Platinized CdS/TiO2 Photocatalysts for Hydrogen Production from Water under Visible Light
Location and State of Pt in Platinized CdS/TiO2 Photocatalysts for Hydrogen Production from Water under Visible Light
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DOI：
10.1021/jp804699c
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发表时间：
2008-11-06
影响因子：
3.7
通讯作者：
Lee, Jae Sung
中科院分区：
文献类型：
--
作者：
Jang, Jum Suk;Choi, Sun Hee;Lee, Jae Sung
采用光沉积（PD）、湿法浸渍（WI）和化学还原（CR）等不同方法对CdS/TiO2复合光催化剂进行铂化，并研究其在可见光下从水中制氢的性能。所有 Pt 物种均处于金属态，但 PD 和 WI 光催化剂含有缺电子 Pt。特别是，在 WI 催化剂中发现了 Pt-Ti 的形成，这导致了 Pt 的电子缺陷。由于光电子从激发的 CdS 向 Pt 的有利扩散，这两种缺电子 Pt 光催化剂表现出更高的析氢速率。在 PD 和 WI 光催化剂之间，PD 催化剂表现出较低的速率，因为催化剂中的部分 Pt 位于 US 上，而对于 WI 和 CR 催化剂，所有 Pt 物质都位于 TiO2 纳米颗粒上。结果表明，Pt 的位置和电子态对于铂化 CdS/TiO2 光催化剂在水制氢中的高性能非常重要。
CdS/TiO2 composite photocatalysts were platinized by different methods such as photodeposition (PD), wet impregnation (WI), and chemical reduction (CR), and studied for hydrogen production from water under visible light. All Pt species were in the metallic state, yet PD and WI photocatalysts contained electron-deficient Pt. In particular, Pt-Ti formation was identified in the WI catalyst, which contributed to electron deficiency of Pt. These two photocatalysts of electron-deficient Pt exhibited higher rates of hydrogen evolution due to favorable diffusion of photoelectrons from excited CdS toward the Pt. Between PD and WI photocatalysts, the PD catalyst showed a lower rate because part of the Pt in the catalyst resided on US, whereas all Pt species were located on TiO2 nanoparticles for WI and CR catalysts. The results indicate that the location as well as the electronic state of Pt is important for the high performance of platinized CdS/TiO2 photocatalysts in hydrogen production from water.