Photocatalytic hydrogen peroxide production by anthraquinone-augmented polymeric carbon nitride
Photocatalytic hydrogen peroxide production by anthraquinone-augmented polymeric carbon nitride
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DOI：
10.1016/j.apcatb.2018.01.060
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发表时间：
2018-08-05
影响因子：
22.1
通讯作者：
Kim, Jae-Hong
中科院分区：
文献类型：
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作者：
Kim, Hyoung-il;Choi, Yeoseon;Kim, Jae-Hong
我们描述了利用蒽醌（AQ）的选择性催化特性用于太阳能光催化合成过氧化氢（H2 O2），作为基于有机溶剂和能源密集型行业基准工艺的绿色替代品，所述工艺也依赖于蒽醌催化。我们通过将AQ锚定到聚合氮化碳（C3 N4）上来实现这一点，聚合氮化碳是一种无金属的可见光光催化剂（带隙能量= 2.7 eV），先前已证明可用于选择性H2 O2合成。一个净H2 O2生产率为361 μ mol g（-1）h（-1）和表观量子产率（AQY）为19.5%，在380 nm激发下，实现使用AQ-augmented C3 N4在模拟1.5太阳光照下，在存在的有机电子供体（2-丙醇），这些结果分别是4.4倍和8.3倍高于裸C3 N4，分别报告。一系列实验分析证实了AQ助催化剂在以下方面的独特作用：（i）从C3 N4的导带捕获电子，从而减少无用的激子复合，这在裸C3 N4中是普遍的;（ii）有效地介导电子转移以驱动氢化反应，从而由AQ形成蒽氢醌（AQH（2））;和（iii）通过AQH（2）脱氢回AQ催化氧还原成H2 O2，导致H2 O2的容易和选择性形成。此外，减少分解所产生的H2 O2的C3 N4/AQ复合光催化剂，当与裸C3 N4或C3 N4与常见的金属助催化剂，如Pt和Ag的复合相比，被发现有助于显着提高H2 O2的生产，通过有机物和水的氧化。
We describe the exploitation of the selective catalytic property of anthraquinone (AQ) for solar photocatalytic synthesis of hydrogen peroxide (H2O2) as a green, sustainable alternative to organic-solvent-based and energy intensive industry-benchmark processes that also rely on AQ catalysis. We accomplished this by anchoring AQ onto polymeric carbon nitride (C3N4), a metal-free visible light photocatalyst (band gap energy = 2.7 eV), that has been previously demonstrated for selective H2O2 synthesis. A net H2O2 production rate of 361 mu mol g(-1) h(-1) and an apparent quantum yield (AQY) of 19.5% at 380 nm excitation were achieved using AQ-augmented C3N4 under simulated 1.sun illumination in the presence of an organic electron donor (2-propanol); these results were 4.4-fold and 8.3-fold higher than those reported for bare C3N4, respectively. A suite of experimental analyses confirmed the unique roles of AQ co-catalysis in (i) capturing electrons from the conduction band of C3N4, thereby reducing futile exciton recombination, which is otherwise prevalent in bare C3N4; (ii) effectively mediating electron transfer to drive hydrogenation reaction to form anthrahydroquinone (AQH(2)) from AQ; and (iii) catalyzing oxygen reduction to H2O2 through the dehydrogenation of AQH(2) back to AQ, resulting in the facile and selective formation of H2O2. In addition, the reduced decomposition of produced H2O2 by the C3N4/AQ composite photocatalysts, when compared to bare C3N4 or C3N4 composited with common metallic co-catalysts such as Pt and Ag, was found to contribute to the significant enhancement in H2O2 production through the oxidation of both organic and water.