Carbon nitride with electron storage property: Enhanced exciton dissociation for high-efficient photocatalysis
Carbon nitride with electron storage property: Enhanced exciton dissociation for high-efficient photocatalysis
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DOI：
10.1016/j.apcatb.2018.05.003
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发表时间：
2018-11
期刊：
影响因子：
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通讯作者：
Zhenxing Zeng;X. Quan;Hongtao Yu;Shuo Chen;Yaobin Zhang;Huimin Zhao;Shushen Zhang
中科院分区：
文献类型：
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作者：
Zhenxing Zeng;X. Quan;Hongtao Yu;Shuo Chen;Yaobin Zhang;Huimin Zhao;Shushen Zhang
激子效应源于电子与空穴之间的库仑吸引，在聚合物材料的光催化过程中起着重要的作用，但长期以来一直被忽视。从热载流子产生的角度出发，提出将Frenkel激子解离作为提高聚合物光催化剂光催化性能的有效途径。在此，我们以石墨化碳氮化物(g-C3N4)为例，验证了赋予g-C3N4电子存储能力可以通过从电子储存位附近的束缚电子-空穴对中提取电子来促进激子解离，从而提高热载流子的获得率，抑制电荷复合。得益于这些优点，所制备的材料对析氢和产生过氧化氢都表现出良好的光催化性能。结果表明，氢气在420 nm处的表观量子产率(AQY)达到55%，远高于已报道的大多数聚合物材料。这项研究为利用激子工程设计高性能太阳能转化的高性能聚合物光催化剂提供了一条新途径。
Excitonic effect, originated from the strong Coulomb attraction between electron and hole, plays an important role in the photocatalytic process of polymeric materials but has been long ignored. In view point of hot-carriers generation, the dissociation of Frenkel excitons is proposed as an effective way to improve the photocatalytic performance of polymeric photocatalysts. Herein, by taking graphitic carbon nitride (g-C3N4) as an example, we verify that endowing g-C3N4with electron storage ability can facilitate exciton dissociation by extracting electrons from bound electron-hole couples around the electron stotage sites, therefore enhancing the hot-carriers harvest and suppressing the charge recombination. Benefiting from these advantages, the as-prepared material demonstrates excellent photocatalytic performance for both H2evolution and H2O2generation. As a result, the apparent quantum yield (AQY) for H2evolution at 420 nm reaches 55%, which is much higher than most of the reported polymeric materials. The study described here offers a new way for designing advanced polymeric photocatalysts toward high performance solar energy conversion via excitonic engineering.