Enhanced CO2 photocatalytic reduction on alkali-decorated graphitic carbon nitride
Enhanced CO2 photocatalytic reduction on alkali-decorated graphitic carbon nitride
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碱修饰石墨氮化碳的增强 CO2 光催化还原
DOI：
10.1016/j.apcatb.2017.05.064
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发表时间：
2017-11-05
影响因子：
22.1
通讯作者：
Wang, Lianzhou
中科院分区：
文献类型：
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作者：
Sun, Zhuxing;Fischer, Julia Melisande Theresa Agatha;Wang, Lianzhou
在这项工作中，氢氧化钾（KOH）在g-C3N4上的修饰显着提高了石墨碳氮化物（g-C3N4）上二氧化碳（CO2）的可见光光催化还原性能。更重要的是，通过各种表征、控制实验和密度泛函理论 (DFT) 计算，深入讨论了 KOH 的作用。结果发现，KOH 修饰除了显着增强 CO2 吸附能力外，对 g-C3N4 的形貌、元素态、BET 表面积和光吸附没有任何显着差异。 KOH对g-C3N4的促进作用主要是由氢氧根离子（OH-）发挥作用，既充当空穴受体又充当驱动力，以保持催化剂表面上动态稳定的H2CO3量（可能是要还原的CO2的主要形式）。此外，利用计算结果揭示并进一步解释了NaOH和KOH对g-C3N4的不同程度的影响。这项研究补充了目前对碱促进光催化过程的理解，并为二氧化碳光催化还原机制提供了新的见解。 (C) 2017 年由 Elsevier B.V. 出版
In this work, visible -light photocatalytic reduction performance of carbon dioxide (CO2) on graphitic carbon nitride (g-C3N4) was significantly promoted by the decoration of potassium hydroxide (KOH) on g-C3N4. More importantly, the role of KOH was thoroughly discussed via various characterizations, control experiments and density functional theory (DFT) calculations. It was found that KOH decoration did not result in any significant difference regards to the morphology, elemental states, BET surface area and light adsorption of g-C3N4 except a drastically enhanced CO2 adsorption capacity. The promotion effect of KOH on g-C3N4 was mainly contributed by the hydroxide ion (OH-) functioning as both a hole accepter and a driving force to keep a dynamically stable amount of H2CO3 (probably the major form of CO2 to be reduced) on the surface of the catalyst. Moreover, the different extents of influence of NaOH and KOH on g-C3N4 were revealed and further explained using computational results. This study supplements current understanding on alkali-promoted photocatalytic processes and provides new insights into the mechanism of CO2 photocatalytic reduction. (C) 2017 Published by Elsevier B.V.