Titanium dioxide/carbon nitride nanosheet nanocomposites for gas phase CO2 photoreduction under UV-visible irradiation
Titanium dioxide/carbon nitride nanosheet nanocomposites for gas phase CO2 photoreduction under UV-visible irradiation
复制标题
DOI：
10.1016/j.apcatb.2018.10.023
复制
发表时间：
2019-03-01
影响因子：
22.1
通讯作者：
Petit, Camille
中科院分区：
文献类型：
--
作者：
Crake, Angus;Christoforidis, Konstantinos C.;Petit, Camille
在光催化领域，特别是CO2光还原领域，纳米复合材料的配方提供了设计具有独特的一组结构、光电和化学特征的材料平台的途径，从而解决了单相材料的缺点并允许协同效应。采用水热原位生长法制备了由二氧化钛（TiO 2）和氮化碳纳米片（CNNS）组成的无机/有机复合光催化剂。具体而言，使用预先形成的CNNS来合成TiO 2/CNNS异质结构，并控制TiO 2小面的形成。这种合成方法通过增加CO2吸附容量和促进电荷转移来改善催化性能。这些材料通过各种光谱、成像和分析技术进行了表征，以研究它们的结构（从纳米到宏观）、化学和光学特性。在CNNS上有效地生长了TiO 2纳米颗粒。测量了复合材料的CO2吸附能力，并测试了它们在UV-Vis照射下以氢气作为还原剂在非均相气-固系统中的CO2光还原，以将联合收割机CO2捕获和转化结合成一个单步过程。在不添加任何贵金属助催化剂的情况下进行催化测试。与其组成材料相比，该复合材料表现出增强的CO2吸附能力和光催化CO2转化率（> 10倍增加），并且优于TiO 2 P25基准材料。具有更多{001} TiO 2晶面的TiO 2/CNNS复合材料的催化活性最高。使用瞬态吸收光谱（TAS）的进一步调查显示，控制面形成改善界面转移在TiO 2/CNNS结。基于光谱分析以及CO2吸附和CO2转化结果，提出了光催化机理。
In the field of photocatalysis and particularly that of CO2 photoreduction, the formulation of nanocomposites provids avenues to design a material platform with a unique set of structural, optoelectronic and chemical features thereby addressing shortcomings of single-phase materials and allowing synergistic effects. In this work, inorganic/organic composite photocatalysts for CO2 reduction comprised of titanium dioxide (TiO2) and carbon nitride nanosheets (CNNS) were synthesized using a hydrothermal in-situ growth method. Specifically, preformed CNNS were used to synthesize TiO2/CNNS heterostructures with control over the TiO2 facet formation. This synthesis approach improved the catalytic properties by increasing CO2 adsorption capacity and facilitating charge transfer. The materials were characterised by various spectroscopic, imaging, and analytical techniques to investigate their structural (from nano- to macroscale), chemical, and optical properties. TiO2 nanoparticles were efficiently grown on the CNNS. The CO2 adsorption capacity of the composites was measured, and they were tested for CO2 photoreduction under UV-Vis illumination with hydrogen as the reducing agent in a heterogeneous gas-solid system to combine CO2 capture and conversion into a single-step process. Catalytic tests were performed without adding any precious metal co-catalyst. The composites exhibited enhanced CO2 adsorption capacity and photocatalytic CO2 conversion compared to their constituent materials ( > ten-fold increase) and outperformed the TiO2 P25 benchmark material. The TiO2/CNNS composite with more {001} TiO2 facets was the most catalytically active. Further investigations using transient absorption spectroscopy (TAS) revealed the control of facet formation improved interfacial transfer at the TiO2/CNNS junction. A photocatalytic mechanism was proposed based on the spectroscopic analyses as well as the CO2 adsorption, and CO2 conversion results.