Bismuth-copper vanadate BiCu2VO6 as a novel photocatalyst for efficient visible-light-driven oxygen evolution.
Bismuth-copper vanadate BiCu2VO6 as a novel photocatalyst for efficient visible-light-driven oxygen evolution.
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DOI：
10.1002/cphc.200500278
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发表时间：
2005-12
期刊：
影响因子：
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通讯作者：
Haimei Liu;Ryuhei Nakamura;Y. Nakato
中科院分区：
文献类型：
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作者：
Haimei Liu;Ryuhei Nakamura;Y. Nakato
利用金属氧化物光催化剂对水和有机化合物进行光氧化，从太阳能转化（水裂解）[1，2]和环境清洁的角度来看，已经引起了强烈的关注。[3]这种方法的一个很大的优点是它提供实用的低成本系统的潜在能力。到目前为止，已经对仅在UV光照射下起作用的TiO 2光催化剂进行了大量研究。为了在太阳光照射下获得高的光反应产率，开发高效、稳定、可见光响应的光催化剂是必不可少的。众所周知，WO 3是稳定的，并且可以在可见光照射下将水光氧化成O2和H+，[4，5]但是其带隙（Eg= 2.8 eV）对于有效的太阳光吸收来说仍然太大。此外，导带边缘太深，光激发电子不能放出氢。近年来，人们努力寻找有效的可见光响应光催化剂，并发现了相当数量的化合物，如N-，[6，7] C-，[8]或S-掺杂的[9] TiO 2，Cr和Sb共掺杂的TiO 2，[10] BiVO 4，[11]和TaON。[12]有趣的是，对于大多数这些光催化剂，可见光响应是通过引入一个新的中间间隙水平以上的O-2 p价带，这是有利于保持导带边能量高，也就是说，为获得有效的还原反应的电子在导带。特别是，BiVO 4（Eg= 2.4 eV）是非常感兴趣的，因为据报道，这种化合物具有混合的Bi-6s和O-2 p价带，并显示出高的光催化O2的释放活性。[11]最近，我们研究了一系列新的混合金属氧化物，表示为BiMII 2 VO 6（MII：二价金属，如Zn II和Cu II），目的是通过能带调制提高光催化活性。在这里，我们报告说，BiCu 2 VO 6显示出更高的活性的光催化析氧相比，BiVO 4。结果很重要，
Photo-oxidation of water and organic compounds with metaloxide photocatalysts has been attracting strong attention in view of solar energy conversion (water splitting)[1, 2] and environmental cleaning.[3] A large merit of this method is its potential ability of providing practicable low-cost systems. Up to now, a large number of studies have been performed on a TiO2 photocatalyst that works only under UV-light irradiation. To get high photoreaction yields under solar light irradiation, development of efficient and stable, visible-light responsive photocatalysts is indispensable. It is well known that WO3 is stable and can photo-oxidize water into O2 and H+ under visible light irradiation,[4, 5] but its band-gap (Eg= 2.8 eV) is still too large for efficient solar-light absorption. Besides, the conduction band edge is too deep for photoexcited electrons to evolve hydrogen. Recently, much effort has been made to search for efficient visible-light-responsive photocatalysts and a considerable number of compounds have been found, such as N-,[6, 7] C-,[8] or S-doped [9] TiO2, Cr and Sb co-doped TiO2,[10] BiVO4,[11] and TaON.[12] Interestingly, for most of these photocatalysts, the visible-light responses are given by introduction of a new mid-gap level above the O-2p valence band, which is favorable for keeping the conduction band edge energetically high, that is, for obtaining effective reduction reactions by electrons in the conduction band. In particular, BiVO4 (Eg= 2.4 eV) is of much interest, because it is reported that this compound has the mixed Bi-6s and O-2p valence band and shows high activity for photocatalytic O2 evolution.[11]Recently, we have studied a novel series of mixed metal oxides, denoted by BiMII 2VO6 (MII: divalent metals such as ZnII and CuII), with the aim to improve the photocatytic activity through energy band modulation. Herein, we report that BiCu2VO6 shows higher activity for the photocatalytic oxygen evolution compared to BiVO4. The result is quite important,