Stable multiphasic 1T/2H MoSe2 nanosheets integrated with 1D sulfide semiconductor for drastically enhanced visible-light photocatalytic hydrogen evolution
Stable multiphasic 1T/2H MoSe2 nanosheets integrated with 1D sulfide semiconductor for drastically enhanced visible-light photocatalytic hydrogen evolution
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稳定的多相 1T/2H MoSe2 纳米片与一维硫化物半导体集成，可显着增强可见光光催化析氢
DOI：
10.1016/j.apcatb.2018.07.002
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发表时间：
2018-12-15
期刊：
影响因子：
--
通讯作者：
Tao, Xia
中科院分区：
文献类型：
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作者：
Li, Nan;Wu, Jiaojiao;Tao, Xia
在可见光催化析氢反应中，低成本、高效的无贵金属助催化剂是非常需要的。在此，我们报道了新型的和高效的无贵金属的多相MoSe 2纳米片的合成和表征，所述多相MoSe 2纳米片由金属IT相和半导体2 H相MoSe 2（记为1 T/2 H MoSe 2）组成，并且它们作为助催化剂与1D CdS纳米棒形成光催化异质结构（记为1 T/2 H-MC）。为了比较，常规的2 H MoSe 2和相应的异质结构2 H MoSe 2/CdS，即2 H-MC平行合成。光谱/电化学测试表明，1 T/2 H MoSe 2催化剂比2 H MoSe 2具有更窄的禁带宽度、更多的活性位和更好的导电性.结果表明，优化后的1 T/2 H-MC-10%催化剂的可见光（λ> 420 nm）光催化HER速率为93.4 mmol/g/h，明显高于裸CdS（10.8 mmol/g/h）、2 H-MC-10%（30.4 mmol/g/h）和Pt/CdS（50.4 mmol/g/h）。这样的H-2产生速率也超过了所有报道的基于MoSe 2的异质结构光催化剂。最重要的是，多相1 T/2 H MoSe 2在老化数月后保持稳定，并且1 T/2 H-MC-10%的HER活性被证明即使在8次可见光HER循环后也没有衰减。
Low-cost and efficient noble-metal-free cocatalysts on semiconductors are highly desirable for visible-light photocatalytic hydrogen evolution reaction (HER). Herein, we report the synthesis and characterizations of novel and high-efficiency noble-metal-free multiphasic MoSe2 nanosheets composed of metallic IT phase and semiconducting 2H phase MoSe2 (denoted as 1T/2H MoSe2), and their implementation as cocatalysts to form photocatalytic heterostructure with 1D CdS nanorods (denoted as 1T/2H-MC). For comparison, conventional 2H MoSe2 and corresponding heterostructure 2H MoSe2/CdS i.e. 2H-MC were synthesized in parallel. The spectroscopic/electrochemical assays show that the 1 T/2H MoSe2 cocatalyst exhibits narrower bandgap, more active sites and better conductivity with respect to 2H MoSe2. As a consequence, the optimized 1T/2H-MC-10% exhibits drastically enhanced visible-light (lambda > 420 nm) photocatalytic HER rate of 93.4 mmol/g/h, obviously higher than those of bare CdS (10.8 mmol/g/h), 2H-MC-10% (30.4 mmol/g/h) and Pt/CdS (50.4 mmol/g/h), respectively. Such an H-2 production rate also exceeds all reported MoSe2-based heterostructure photocatalysts. Most importantly, the multiphasic 1 T/2H MoSe2 remained stable after aging for several months and the HER activity of the 1 T/2H-MC-10% was demonstrated to have no decay even after 8 cycling of visible-light HER.