超薄C-N层/二维金属硫化物插层交错复合材料的可控设计及光还原CO2制备碳氢燃料的性能与机理研究

The continued consumption of fossil fuels exacerbates CO2 emissions and energy crises which severely restricts economic development. Photocatalytic technology can achieve the conversion of CO2 into hydrocarbons to solve the energy crisis while reducing the content of CO2 in the atmosphere, and mitigate the the greenhouse effect. According to this project, the ultra-thin C-N layer/two-dimensional metal sulfide Intercalated and interlaced composite photocatalytic materials will be prepared by the auxiliary technique like hydrothermal and microwave. The effects of band structure and photocatalytic performance of C-N materials which caused by the defect energy level introduced by phosphorus and boron elements doping will be studied; The controllable synthesis technology and modulation methods of two-dimensional metal sulfide are to study; The size effect of ultra-thin C-N layer/two-dimensional metal sulfide composite photocatalytic materials will be studied; The intercalation structure and interfacial effects of composite photocatalytic materials are going to be studied; Studying on the structure-activity relationship and interfacial theories of layered compounds and intercalation agents of composite photocatalysts; The migration mechanism and interface transfer behavior of electrons during the photocatalytic process of composite materials will be researched; The mechanism and thermodynamics/Kinetic process of photocatalytic selective conversion of CO2 to prepare hydrocarbon fuel by composite materials are going to be studied. The activity and selectivity mechanism of ultra-thin C-N layer/two-dimensional metal sulfide composite photocatalytic materials for photocatalytic conversion of CO2 will be elucidate, and a model for the preparation of hydrocarbon fuels by photocatalytic reduction and conversion of CO2 will be established.

化石燃料的不断消耗加剧了CO2的排放和能源危机，严重制约经济的发展。光催化技术可实现将CO2转化为碳氢化合物解决能源危机的同时降低大气中CO2含量，缓解温室效应。据此本课题利用水热、微波等辅助技术制备超薄C-N层/二维金属硫化物插层交错复合光催化材料，研究P、B等元素掺杂所引入的缺陷能级对C-N材料能带结构及光催化性能的影响；研究二维金属硫化物的而可控合成技术及调变方法；研究超薄C-N层/二维金属硫化物复合光催化材料的尺寸效应；研究复合光催化材料的嵌插层间结构与界面效应；研究复合光催化材料层状化合物与插层剂客体间的构效关系及界面理论；研究复合材料光催化过程中电子的迁移机制及界面传递行为；研究复合材料光催化选择性转化CO2制备碳氢燃料的机理及热力学、动力学过程。阐明超薄C-N层/二维金属硫化物复合光催化材料催化转化CO2的活性与选择性机制，建立其光催化还原转化CO2制备碳氢燃料的模型。

二维金属硫化物独特的电化学特性与超薄C-N层状材料优异的层间效应，对增强光还原CO2转化碳氢化合物的活性与提高材料稳定性具有重要意义。本课题拟通过CO2分子的光催化转化过程为研究对象，利用煅烧处理、化学还原以及水热（溶剂热）技术制备多元多维插层复合光催化材料，探究多维插层材料的构筑思路与调控策略对催化性能的影响；为提高金属硫化物的稳定性，以金属硫化物为电子受体和空穴供体构建异质结，引入rGO材料构建插层体系有效降低金属硫化物的光腐蚀现象，提高其稳定性；调控不同类型插层组分（半导体/等离激元）与C-N/金属硫化物材料复合界面机制及构筑手段，探究以上过程对复合材料的结构影响；多元多维材料界面为光生电子空穴对的高效分离提供了有效路径。此外，该过程还提高了催化剂对CO2分子的捕获能力。通过对多元界面间光生载流子传输机制的研究及不同修饰手段对该过程的增强机理，归纳了插层结构对光还原CO2性能的提高机理；研究插层结构在光还原CO2过程当中所涉及的热/动力学过程；结合理论计算、原为红外以及13C同位素标定技术，对CO2的光还原过程进行探究；阐明不同插层客体对多元层间复合光催化材料的活性和催化稳定性的提高机制，建立光还原CO2转化碳氢燃料的反应模型；尝试从构效关系及多元界面理论对存在的科学问题进行解释；对光还原CO2过程中所涉及的理论问题进行探索，从理论上知道和解决C-N/金属硫化物多元插层复合光催化材料在实践应用中所存在的问题。