石墨烯作为一种结构、性能独特的二维碳材料在CO2还原转化过程中展现出良好的应用前景，寻找石墨烯丰富的碳质前驱体和可控制备方法是实现其大规模应用的基础。煤炭作为一种富碳矿物资源，含有丰富的官能团和高芳香度纳米石墨微晶结构。以煤炭及其衍生物为碳源制备高附加值石墨烯材料具有独特优势，是同时实现煤炭材料清洁化利用和石墨烯低成本实际应用的重要途径。针对不同变质程度煤种，从化学组成和煤质结构出发，通过适当的分子剪裁和化学结构组装，成功实现了系列多尺度、多形态煤基石墨烯材料的可控制备。常用的制备方式包括：机械力剪切、化学插层氧化、电化学剥离、气相沉积、阳极电弧放电及液相自组装等。如通过化学氧化或超声物理剪裁煤大分子结构制备零维石墨烯量子点；煤炭热解得到的含碳烃类小分子气体通过化学气相沉积制备二维石墨烯薄膜；煤炭高温石墨化后通过物理或化学剥离得到二维石墨烯纳米片；二维石墨烯经过结构自组装制备三维石墨烯气凝胶。由于煤基石墨烯的组成及其表界面结构具有易调控、可修饰等特性，其在CO2还原过程中展现出良好的催化活性。通过总结煤基石墨烯系列材料在CO2光催化、电催化以及光电催化转化过程中的最新研究，认为煤基石墨烯通过增大反应活性位点和改变催化剂表面结构，能够有效提高CO2还原过程的效率和选择性。最后，针对煤基石墨烯组成和结构的调控，以及CO2还原催化剂的结构设计进行了展望。

As a two-dimensional carbon material with unique structure and properties, graphene shows a good application prospect in the process of CO2 reduction and conversion. Searching for abundant carbonaceous precursors and controllable preparation methods of graphene is the basis for its large-scale application. As a promising mineral resource with rich carbon, coal contains abundant functional groups and high aromatic nano graphite microcrystalline structure. Using coal and its derivatives as carbon sources to prepare high value-added graphene materials has unique advantages, which is an important way to realize the clean utilization of coal and the low-cost practical application of graphene. Based on the chemical composition and structure of different rank coals,  researchers have successfully achieved the controllable preparation of a series of multi-scale and multi-form coal-based graphene materials through appropriate molecular tailoring and chemical structure assembly. Common preparation strategies include: mechanical cleavage and exfoliation, chemical intercalation oxidation, electrochemical exfoliation, chemical vapor deposition, anodic arc discharge and liquid-phase self-assembly, etc. For example, zero dimensional graphene quantum dots are prepared by chemical oxidation or ultrasonic physical tailoring of coal macromolecular structure. Two dimensional graphene films are prepared by chemical vapor deposition (CVD) of carbon containing hydrocarbon small molecule gas obtained from coal pyrolysis. Two-dimensional graphene nanosheets are obtained by physical or chemical exfoliation after graphitization of coal at high temperature. Three dimensional graphene aeroneneneba gels are prepared by structural self-assembly of two-dimensional graphene. Because the composition and surface structure of coal-based graphene are easy to regulate and modify, the coal-based graphene shows good catalytic activity in the process of CO2 reduction. By summarizing the latest research of coal-based graphene series materials in the process of CO2 reduction using photocatalysis, electrocatalysis and photoelectrocatalysis, it is considered that coal-based graphene can effectively improve the efficiency and selectivity of CO2 reduction process by increasing the reaction active sites and changing the surface structure of the catalyst. Finally, the control of the composition and structure of coal-based graphene and the structural design of CO2 reduction catalyst were prospected. 

0 引言

1 煤基石墨烯材料的种类

   1.1 煤基石墨烯量子点

   1.2 煤基二维石墨烯

   1.3 煤基三维石墨烯

2 煤基石墨烯的可控制备方法

   2.1 机械剪切法

   2.2 化学氧化剥离法

   2.3 电化学剥离法

   2.4 气相沉积法

   2.5 阳极电弧放电法

3 煤基石墨烯材料还原CO2的应用

   3.1 光催化还原CO2

   3.2 电催化还原CO2

   3.3 光电催化还原CO2

4 煤基石墨烯在CO2还原转化中的应用展望