Photocatalytic Overall Water Splitting Promoted by Two Different Cocatalysts for Hydrogen and Oxygen Evolution under Visible Light
Photocatalytic Overall Water Splitting Promoted by Two Different Cocatalysts for Hydrogen and Oxygen Evolution under Visible Light
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DOI：
10.1002/anie.201001259
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Domen, Kazunari
中科院分区：
文献类型：
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作者：
Maeda, Kazuhiko;Xiong, Anke;Domen, Kazunari
使用颗粒光催化剂和太阳能的整体水分解作为从可再生资源大规模生产H2而不排放二氧化碳的潜在手段已经引起了显著的关注。[1，2]反应分三步进行：1）光催化剂吸收大于材料带隙能量的光子能量，并在本体中产生光激发的电子-空穴对，2）光激发的载流子分离并迁移到表面而不复合，3）吸附的物种被光生电子和空穴还原和氧化，分别产生H2和O2。前两个步骤强烈依赖于光催化剂的结构和电子性质，而第三个步骤则由额外的催化剂（称为助催化剂）促进。因此，光催化剂和助催化剂的协调发展是非常重要的。由于大多数光催化剂的表面不存在析氢活性位，因此本课题组近年来致力于研究光催化剂表面的析氢活性位。[2b]使用GaN和ZnO的固溶体（下文中缩写为GaN：ZnO），其可以收获高达约100 nm的可见光子。500 nm，[3]含铬过渡金属氧化物[4]或贵金属/氧化铬（核/壳）纳米颗粒（NP）[5]已被证明用作H2析出助催化剂，导致高效的
Overall water splitting using a particulate photocatalyst and solar energy has attracted significant attention as a potential means of large-scale H2 production from renewable resources without carbon dioxide emission.[1, 2] The reaction occurs in three steps: 1) the photocatalyst absorbs photon energy greater than the band-gap energy of the material and generates photoexcited electron–hole pairs in the bulk, 2) the photoexcited carriers separate and migrate to the surface without recombination, and 3) adsorbed species are reduced and oxidized by the photogenerated electrons and holes to produce H2 and O2, respectively. The first two steps are strongly dependent on the structural and electronic properties of the photocatalyst, while the third step is promoted by an additional catalyst (called cocatalyst). Therefore, it is important to develop a photocatalyst and a cocatalyst in harmony.Recently, our group has focused on active sites for H2 evolution on the surface of a photocatalyst, because most photocatalysts lack surface H2 evolution sites.[2b] Using a solid solution of GaN and ZnO (abbreviated GaN: ZnO hereafter) that can harvest visible photons up to ca. 500 nm,[3] chromium-containing transition-metal oxides [4] or noble-metal/chromia (core/shell) nanoparticles (NPs)[5] have been shown to function as H2 evolution cocatalysts, resulting in efficient