Transformation of CO2 into value‐added products via photothermal catalysis has become an increasingly popular route to help ameliorate the energy and environmental crisis derived from the continuing use of fossil fuels, as it can integrate light into well‐established thermocatalysis processes. The question however remains whether negative CO2 emission could be achieved through photothermal catalytic reactions performed in facilities driven by electricity mainly derived from fossil energy. Herein, we propose universal equations that describe net CO2 emissions generated from operating thermocatalysis and photothermal reverse water–gas shift (RWGS) and Sabatier processes for batch and flow reactors. With these reactions as archetype model systems, the factors that will determine the final amount of effluent CO2 can be determined. The results of this study could provide useful guidelines for the future development of photothermal catalytic systems for CO2 reduction.

Two‐dimensional materials (2D M) possess unique structural, optical, and electronic properties in comparison with their bulk counterparts. Therefore, they have been demonstrated to be excellent performers for catalysis (especially photocatalysis). Among these 2D catalytic materials, 2D silicon (2D Si) is an emerging subclass, gifted with Si's high abundance, low toxicity, and strong light‐harvesting ability. Endowed with the universal advantages of 2D M including a large surface area, prolific active sites and loading positions for other elements, and ultrathin thickness for the generation of defects and transportation of photogenerated carriers, 2D Si exhibits additionally distinct surface chemistry and metal‐support interactions through geometrical assembly. These features render 2D Si a competitive candidate for (photo)catalysis, drawing burgeoning interest recently.

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(Photo)Catalysis In article number http://doi.wiley.com/10.1002/solr.202000392, Wei Sun, Deren Yang and co‐workers reviewed the mainstream synthetic techniques and the advantages of 2D‐Si regarding structure, surface chemistry, and possible metal‐support interaction for a variety of catalytic reactions. With the envisagement on the future opportunities of 2D‐Si in photocatalysis, the authors believed that this review could stimulate more interest in this potent material.