Photocatalytic hydrogen production using twinned nanocrystals and an unanchored NiSx co-catalyst
Photocatalytic hydrogen production using twinned nanocrystals and an unanchored NiSx co-catalyst
复制标题
使用孪生纳米晶体和非锚定 NiSx 助催化剂光催化制氢
DOI：
10.1038/nenergy.2016.151
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发表时间：
2016-09-26
期刊：
影响因子：
56.7
通讯作者：
Guo, Liejin
中科院分区：
文献类型：
--
作者：
Liu, Maochang;Chen, Yubin;Guo, Liejin
促进电荷分离以及表面氧化还原反应被认为是改善半导体催化的太阳能氢气产生的核心。为此，由紧密连接的光吸收剂和助催化剂组成的光催化剂受到了极大的关注。在这里，我们将一种高效的Cd_(0.5)Zn_(0.5)S(CZS)纳米孪晶光催化剂与NiS_x助催化剂结合起来用于光产氢。结果表明，以Na2 S/Na2 SO3为空穴清除剂，水中光催化制氢在42 5 nm处的内量子效率接近10 0%。我们的结果表明，NiSx助催化剂并不固定在宿主CZS纳米孪晶的表面，而是以独立的亚纳米团簇的形式存在于反应溶液中。我们认为电荷转移是通过CZS和NiSx团簇之间的碰撞来完成的，这有助于电荷分离并抑制返回反应，导致悬浮液中的高减水率。
Facilitating charge separation as well as surface redox reactions is considered to be central to improving semiconductor-catalysed solar hydrogen generation. To that end, photocatalysts comprising intimately interfaced photo absorbers and co-catalysts have gained much attention. Here, we combine an efficient Cd 0.5 Zn 0.5 S (CZS) nanotwinned photocatalyst with a NiS x co-catalyst for photogeneration of hydrogen. We find that an internal quantum efficiency approaching 100% at 425 nm can be achieved for photocatalytic H 2 production from water with Na 2 S/Na 2 SO 3 as hole scavengers. Our results indicate that the NiS x co-catalyst is not anchored on the surface of the host CZS nanotwins and instead exists in the reaction solution as freestanding subnanometre clusters. We propose that charge transfer is accomplished via collisions between the CZS and NiS x clusters, which aids charge separation and inhibits back reaction, leading to high water reduction rates in the suspension.