Research Progress of Photocatalytic CO₂Reduction Based on Two-dimensional Materials

Abstract

In past decades, global warming, sea level rising, and other climate problems caused by greenhouse effect are becoming more and more serious. Considerable efforts have been paid on developing new technology that can effectively reduce the atmospheric level of carbon dioxide (CO 2 ), the most representative one of greenhouse gases. Solar-driven conversion of CO 2 into high value-added hydrocarbon fuels is considered as the most promising approach to alleviate the current energy crisis and the rising CO 2 level. Benefiting from their high specific surface area and novel electronic structures, two dimensional (2D) materials have drawn intense interest in the field of CO 2 photoreduction. Herein, the latest development of 2D materials for photocatalytic CO 2 reduction is presented, with special emphasis given to the structure-activity relationship in catalytic reactions. The potentials of newly emerged 2D materials including black phosphorus, graphdiyne and covalent organic frameworks as the next generation photocatalysts for CO 2 reduction are then discussed. Finally, the opportunities and challenges in the field of CO 2 photoreduction are featured on the basis of its current development. Keywords two-dimensional materials; photocatalysis; CO 2 photoreduction; structure-activity relationship与传统的、高耗能的捕获或地质封存等手段相比, 实现 CO 2 的资源化是一种更具前景的途径, 能同时缓解 温室效应和能源危机 [3][4] . 基础研究中已开发出热催 化 [5][6][7] 、光催化 [8][9][10] 、电催化 [11][12][13] 、光-电协同催化 [14][15][16] 和有机催化转化 [17][18][19] 等多种途径将 CO 2 分子转化成高 附加值的化学品. 其中, 以太阳能为驱动力的 CO 2 转化 (即光催化 CO 2 还原)具备反应条件温和、环境友好等突 出优点. 光催化 CO 2 还原是模拟自然界植物的光合作 用, 利用水(H 2 O)和 CO 2 制造有机物并释放氧气, 因此 又被称之为"人工光合成" [3,8] . 热力学上, CO 2 极其稳 定的分子, C＝O 双键的解离能高达 750 kJ•mol -1 , 显著 高于还原产物中 C-H 键(430 kJ•mol -1 )和 C-C 键(336 kJ•mol -1 )的键能, 这意味着需要向体系注入大量的能量 才能触发 CO 2 的活化与转化过程 [8] . 同时, 在 CO 2 分子 中, 碳元素是处于最高的氧化态(＋4 价), 在反应中根据 得电子数目的不同可以获得多种产物 [8] . 如表 1 所示, 在光催化反应中, CO 2 通常可以被还原成一氧化碳

Strain‐Tunable Photocatalytic Performance in Two‐Dimensional Janus In2S2X (X=Se,Te) Monolayer as Photocatalyst for CO2 Reduction

“…Among them, Janus materials have received more and more attention because of their potential excellent photocatalytic properties, [12][13] which contain all the advantages of 2D materials (high specific surface area, short carrier migration distance, tunable electron structure, etc.). [14] Furthermore, due to the intrinsic polarization caused by the structural asymmetry, the generated built-in electric field can effectively suppress the recombination of the carrier. In particular, Ju et al [15] found that the conduction band and valence band are respectively contributed by the Se atomic layer and the S atomic layer in the study of WSSe.…”