One-pot fabrication of a double Z-scheme CeCO3OH/g-C3N4/CeO2 photocatalyst for nitrogen fixation under solar irradiation
One-pot fabrication of a double Z-scheme CeCO3OH/g-C3N4/CeO2 photocatalyst for nitrogen fixation under solar irradiation
复制标题
一锅法制备双 Z 型 CeCO3OH/g-C3N4/CeO2 太阳光固氮光催化剂
DOI：
10.1039/c9cy00281b
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发表时间：
2019-06-07
影响因子：
5
通讯作者：
Wang, Xin
中科院分区：
文献类型：
--
作者：
Feng, Xiangwen;Chen, Huan;Wang, Xin
以CeCl 3和石墨化氮化碳（g-C3 N4）为前驱体，采用原位自牺牲水热法制备了CeCO 3OH/g-C3 N4/CeO 2三元光催化剂（简称2Ce-CN）。在不添加任何牺牲剂的情况下，2Ce-CN表现出约1.16mM g-1h-1的增强的固氮活性，这是原始g-C3 N4的4倍。氮光固定性能归因于以下原因的组合。首先，氮在Ce 3+位的化学吸附激活了氮。N键。第二，CeO_2的导带（CB）中的光生电子转移到g-C_3 N_4的价带（VB），而g-C_3 N_4的CB中的电子转移到CeCO_3OH的VB中，这是紧密接触化学结合界面的结果。这种电子转移被证明是一个双Z-计划机制。电荷载流子复合的速率降低，在CeCO 3OH的CB中留下更多的电子以将吸附的氮还原成氨。第三，CeO 2中Ce 4+和Ce 3+之间的价态变化进一步促进了氮的加氢反应。这种简单的自牺牲方法为设计具有优异光催化活性的功能g-C3 N4提供了另一种视角。
A CeCO 3 OH/g-C3N4/CeO2 ternary photocatalyst (abbreviated as 2Ce-CN) was synthesized by a facile in situ self-sacrificing hydrothermal method, using CeCl3 and graphitic carbon nitride (g-C3N4) as precursors. 2Ce-CN exhibited an enhanced nitrogen photofixation activity of approximately 1.16 mM g -1 h -1 without adding any sacrificial agent, which was four times higher than that of pristine g-C3N4. The nitrogen photofixation performance was attributed to a combination of the following reasons. First, the chemical adsorption of nitrogen at Ce3+ sites activated the N. N bond. Second, photogenerated electrons in the conduction band (CB) of CeO2 transferred to the valence band (VB) of g-C3N4, while electrons in the CB of g-C3N4 transferred to the VB of CeCO3OH, as a result of the intimate-contact chemically-bound interface. This electron transfer is shown to be a double Z-scheme mechanism. The rate of charge carrier recombination was reduced, leaving more electrons in the CB of CeCO3OH to reduce the adsorbed nitrogen to ammonia. Third, the valence change between Ce4+ and Ce3+ in CeO2 further promoted the nitrogen hydrogenation reaction. This simple self-sacrificing method provides an alternative perspective for designing functional g-C3N4 with excellent photocatalytic activity.