Emerging porous nanosheets:From fundamental synthesis to promising applications

Metal-organic framework(MOF)nanosheets and covalent organic framework(COF)nanosheets as emerging porous materials nanosheets have captured increasing attention owing to their attractive properties originating from the advantages of large lateral size,ultrathin thickness,tailorable physiochemical environment,flexibility and highly accessible active sites on surface,and the applications of them have been explored in a wide range of fields.Although MOF and COF nanosheets own many similar properties,their applications in various fields show significant differences,probably due to their different compositions and bonding modes.Hence,we summarize the recent progress of MOF and COF nanosheets by comparative analysis on their advantages and limitations in synthesis and applications,providing a more profound and full-scale perspective for researchers or beginners to understand this field.Herein,the categories of preparation methods of MOF and COF nanosheets are firstly discussed,including top-down and bottom-up methods.Secondly,the applications of MOF and COF nanosheets for separation,catalysis,sensing and energy storage are summarized.Finally,based on current achievements,we put forward our personal insights into the challenges and outlooks on the synthesis,characterizations,and promising applications for future research of MOF and COF nanosheets.

不同全球变暖目标下中国气候变化风险区域格局

Climate change will bring huge risks to human society and the economy.Regional climate change risk assessment is an important basic analysis for addressing climate change,which can be expressed as a regional system of comprehensive climate change risk.This study establishes regional systems of climate change risks under the proposed global warming targets.Results of this work are spatial patterns of climate change risks in China,indicated by the degree of climate change and the status of the risk receptors.Therefore,the risks show significant spatial differences.The high-risk regions are mainly distributed in East,South,and central China,while the medium-high risk regions are found in North and southwestern China.Under the 2℃warming target,more than 1/4 of China’s area would be at high and medium-high risk,which is more severe than under the 1.5℃warming target,and would extend to the western and northern regions.This work provides regional risk characteristics of climate change under different global warming targets as a foundation for dealing with climate change.

Two-dimensional covalent organic framework nanosheets:Synthesis and energy-related applications

Two-dimensional(2D)covalent organic framework nanosheets(CONs)are attracting increasing research attention because of their unique properties derived from their ultrathin thickness,high surface-tovolume atomic ratio,and extremely large surface area.2D CONs can provide high transport pathways for charge carriers(e.g.,electrons,holes and ions)through either the conjugated skeletons or the open channels.Therefore,they have shown great potential in energy related applications.In this review,we firstly introduce the recent developments and characteristics of 2D CONs by focusing on the two typical synthetic methods,i.e.,top-down and bottom-up methods.Then,the energy-related applications in energy storage and conversion of 2D CONs are summarized.Finally,we give our personal views on the challenges and perspectives for the future research of 2D CONs and their composites.