Construction of 2D/2D Bi2Se3/g-C3N4 nanocomposite with High interfacial charge separation and photo-heat conversion efficiency for selective photocatalytic CO2 reduction
Construction of 2D/2D Bi2Se3/g-C3N4 nanocomposite with High interfacial charge separation and photo-heat conversion efficiency for selective photocatalytic CO2 reduction
复制标题
DOI：
10.1016/j.apcatb.2020.119232
复制
发表时间：
2020-11-15
影响因子：
22.1
通讯作者：
Zhang, Gaoke
中科院分区：
文献类型：
--
作者：
Huang, Yanhong;Wang, Kai;Zhang, Gaoke
太阳能驱动的二氧化碳转化为高价值燃料被认为是缓解温室效应和能源危机问题的一个有前途的战略。然而，电荷复合速度快、光利用率差、选择性低等问题仍然限制了光催化CO2还原的效率。在这项工作中，开发了一种新型的2D/2D Bi2Se3/g-C3N4异质结复合材料，以研究其对CO2选择性还原的光催化活性。幸运的是，二维Bi2Se3和二维g-C3N4之间形成了密切的相互作用，这对电荷的分离和转移非常有利。在该复合材料中，Bi2Se3不仅起到助催化剂的作用，而且通过有效的光热转换，在光催化反应中起到额外加热器的作用。正如预期的那样，2D/2D Bi2Se3/g-C3N4复合材料在全光谱照射下，将CO2还原为CO的光催化能力大大提高，比原始g-C3N4高约6.3倍。值得注意的是，CO2还原的产物几乎是100%的CO，没有其他碳产物，并且在H-2演化过程中，CO的选择性大于90%。实验测试和DFT计算证实，Bi2Se3/g-C3N4复合材料的光催化CO2还原能力优于其他同类材料，应归因于高度改善的电荷分离和强大的光热转换效率的协同作用。同时，利用原位傅里叶红外对CO2还原过程进行了详细研究。本研究提出的复合材料可能为开发高效的光催化CO2还原成有价值的燃料提供了潜在的策略。
Solar-energy-driven CO2 conversion into high-valued fuels has been considered as a promising strategy to alleviate the greenhouse effect and energy crisis problems. However, the rapid charge recombination, poor light utilization and low selectivity, etc. still limit the efficiency of photocatalytic CO2 reduction. In this work, a novel 2D/2D Bi2Se3/g-C3N4 heterojunction composite has been developed to investigate the improved photocatalytic activity towards CO2 reduction selectively. Fortunately, an intimate interaction was formed between 2D Bi2Se3 and 2D g-C3N4, which is very beneficial for the charge separation and transfer. In this composite, Bi2Se3 not only acted as a cocatalyst liked role, but also played as an extra heater for photocatalytic reaction by effective phototo-heat conversion. As expected, the 2D/2D Bi2Se3/g-C3N4 composite presented much improved photocatalytic ability for CO2 reduction to CO, which is about 6.3 times higher than that of pristine g-C3N4 under the irradiation of full spectrum. Notably, the product from CO2 reduction was nearly 100% CO without other carbon products, and the selectivity for CO was greater than 90% over H-2 evolution. The experimental tests and DFT calculations confirmed that the superiority of photocatalytic CO2 reduction ability of Bi2Se3/g-C3N4 composite over other counterparts should be attributed to the synergetic effect of highly improved charge separation and strong photo-to-heat conversion efficiency. Meanwhile, the CO2 reduction process was studied by in-situ FTIR in detail. The as-proposed composite in this work might provide a potential strategy for developing high efficiency of photocatalytic CO2 reduction to valuable fuels.