Janus 双层结通过原子级电荷流导向实现优越的可见光制氢。
Superior visible light hydrogen evolution of Janus bilayer junctions via atomic-level charge flow steering.
机构信息
Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Institute of Environmental Chemistry, College of Chemistry, Central China Normal University, Wuhan 430079, China.
Institute of Nanoscience and Nanotechnology, College of Physical Science and Technology, Central China Normal University, Wuhan 430079, China.
出版信息
Nat Commun. 2016 May 9;7:11480. doi: 10.1038/ncomms11480.
Although photocatalytic hydrogen evolution (PHE) is ideal for solar-to-fuel conversion, it remains challenging to construct a highly efficient PHE system by steering the charge flow in a precise manner. Here we tackle this challenge by assembling 1T MoS2 monolayers selectively and chemically onto (Bi12O17) end-faces of Bi12O17Cl2 monolayers to craft two-dimensional (2D) Janus (Cl2)-(Bi12O17)-(MoS2) bilayer junctions, a new 2D motif different from van der Waals heterostructure. Electrons and holes from visible light-irradiated Bi12O17Cl2 are directionally separated by the internal electric field to (Bi12O17) and (Cl2) end-faces, respectively. The separated electrons can further migrate to MoS2 via Bi-S bonds formed between (Bi12O17) and MoS2 monolayers. This atomic-level directional charge separation endows the Janus bilayers with ultralong carrier lifetime of 3,446 ns and hence a superior visible-light PHE rate of 33 mmol h(-1) g(-1). Our delineated Janus bilayer junctions on the basis of the oriented assembly of monolayers presents a new design concept to effectively steer the charge flow for PHE.
虽然光催化析氢（PHE）是太阳能转化为燃料的理想选择，但通过精确控制电荷流动来构建高效的 PHE 系统仍然具有挑战性。在这里，我们通过选择性地和化学地将 1T-MoS2 单层组装到 Bi12O17Cl2 单层的（Bi12O17）端面上来解决这一挑战，从而构建二维（2D）Janus（Cl2）-（Bi12O17）-（MoS2）双层结，这是一种不同于范德华异质结构的新型 2D 结构。来自 Bi12O17Cl2 的可见光照射的电子和空穴分别通过内部电场定向分离到（Bi12O17）和（Cl2）端面。分离的电子可以通过在（Bi12O17）和 MoS2 单层之间形成的 Bi-S 键进一步迁移到 MoS2。这种原子级的定向电荷分离使 Janus 双层具有超长的载流子寿命 3446 ns，因此具有优异的可见光 PHE 速率 33 mmol h(-1) g(-1)。我们基于单层定向组装的明确的 Janus 双层结提出了一种新的设计概念，可有效控制 PHE 的电荷流动。
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