Selective Photocatalytic Reduction of CO2 to CH4 Modulated by Chloride Modification on Bi2WO6 Nanosheets
Selective Photocatalytic Reduction of CO2 to CH4 Modulated by Chloride Modification on Bi2WO6 Nanosheets
复制标题
Bi2WO6 纳米片上氯化物修饰调节 CO2 选择性光催化还原为 CH4
DOI：
10.1021/acsami.0c11551
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发表时间：
2020-12-09
影响因子：
9.5
通讯作者：
Li, Zhong-Jun
中科院分区：
文献类型：
--
作者：
Li, Yan-Yang;Fan, Jun-Sheng;Li, Zhong-Jun
太阳能光催化CO2还原为CH 4被认为是缓解能源危机和温室效应的一条有效途径。然而，现有的CO2光还原技术往往忽视光氧化半反应的作用以及水氧化产生的质子对CH 4生成的影响，导致CO2转化效率低，CH 4选择性差。在本研究中，一系列的氯化物修饰的Bi 2 WO 6纳米片的构建，在氯化物辅助光催化水氧化的观点。结果表明，合成的样品的甲烷产率可以提高到约10倍，相比没有Cl-改性。此外，CH 4的选择性还可以通过氯离子的负载量来调节，Bi 2 WO 6的负载量为51.29%，最高可达94.98%。氯化物改性不仅改变了催化剂的形貌，而且改变了水的氧化途径，从而提高了产物收率。对中间产物的进一步研究和密度泛函理论计算证实，Bi 2 WO 6纳米片上的Cl-不仅促进了H2O的氧化，而且降低了中间产物 *CHO生成的能垒，从而促进了CH 4的生成。本文获得的结果可以提供一些启发性的见解设计的高选择性的光催化剂，有效的CO2还原。
Solar-driven photocatalytic CO2 reduction into CH4 with H2O is considered to be a promising way to alleviate the energy crisis and greenhouse effect. However, current CO2 photoreduction technologies tend to overlook the role of photooxidation half reaction as well as the effect of the protons produced by water oxidation on CH4 generation, resulting in low CO2 conversion efficiency and poor CH4 selectivity. In the present study, a series of chloride-modified Bi2WO6 nanosheets were constructed in view of chloride-assisted photocatalytic water oxidation. The results show that the CH4 yield of the synthesized sample can be enhanced up to about 10 times compared to that with no Cl- modification. Besides, the selectivity of CH4 can be regulated by the loading amount of chloride, varying from 51.29% for Bi2WO6 to 94.98% for the maximum. The increase of product yield is attributed to chloride modification, which not only changed the morphology of the catalyst, but also modified the pathway of water oxidation. Further studies on intermediate products and the density functional theory calculation confirm that the Cl- ions on Bi2WO6 nanosheets not only promote H2O oxidation, but also lower the energy barrier for intermediate *CHO generation, thus facilitating CH4 production. The results gained herein may provide some illuminating insights into the design of a highly selective photocatalyst for efficient CO2 reduction.