Pt-Cu bimetallic alloy nanoparticles supported on anatase TiO2: highly active catalysts for aerobic oxidation driven by visible light.
Pt-Cu bimetallic alloy nanoparticles supported on anatase TiO2: highly active catalysts for aerobic oxidation driven by visible light.
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DOI：
10.1021/nn403954p
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发表时间：
2013-09
期刊：
影响因子：
17.1
通讯作者：
Yasuhiro Shiraishi;Hirokatsu Sakamoto;Yoshitsune Sugano;S. Ichikawa;T. Hirai
中科院分区：
文献类型：
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作者：
Yasuhiro Shiraishi;Hirokatsu Sakamoto;Yoshitsune Sugano;S. Ichikawa;T. Hirai
可见光（λ > 450 nm）照射负载于纳米TiO 2上的Pt-Cu纳米合金纳米颗粒（~3-5 nm）可有效促进好氧氧化。这是facilicated通过带间激发的Pt原子的可见光，然后由激活的电子转移到的Pt的导带。在纳米颗粒上形成的正电荷氧化基材，导带电子还原分子氧，促进光催化循环。在550 nm单色光照射下，Pt-Cu合金催化剂上反应的表观量子产率约为17%，远高于单金属Pt催化剂上的表观量子产率（约7%）。Cu与Pt的合金化降低了纳米颗粒的功函数，并降低了在纳米颗粒/Pt异质结处产生的肖特基势垒的高度。这促进了从光活化的纳米颗粒到纳米粒子的有效电子转移，导致增强的光催化活性。Pt-Cu合金催化剂可被太阳光成功活化，并可在环境温度下有效和选择性地对醇类进行有氧氧化。
Visible light irradiation (λ > 450 nm) of Pt-Cu bimetallic alloy nanoparticles (~3-5 nm) supported on anatase TiO2 efficiently promotes aerobic oxidation. This is facilicated via the interband excitation of Pt atoms by visible light followed by the transfer of activated electrons to the anatase conduction band. The positive charges formed on the nanoparticles oxidize substrates, and the conduction band electrons reduce molecular oxygen, promoting photocatalytic cycles. The apparent quantum yield for the reaction on the Pt-Cu alloy catalyst is ~17% under irradiation of 550 nm monochromatic light, which is much higher than that obtained on the monometallic Pt catalyst (~7%). Cu alloying with Pt decreases the work function of nanoparticles and decreases the height of the Schottky barrier created at the nanoparticle/anatase heterojunction. This promotes efficient electron transfer from the photoactivated nanoparticles to anatase, resulting in enhanced photocatalytic activity. The Pt-Cu alloy catalyst is successfully activated by sunlight and enables efficient and selective aerobic oxidation of alcohols at ambient temperature.