Hotpots and trends of covalent organic frameworks (COFs) in the environmental and energy field: Bibliometric analysis

Covalent organic frameworks (COFs) have attracted extensive attention due to their low density, adjustable structure, functionalization, and good stability. This paper systematically and comprehensively describes to qual-itatively and quantitatively the progress, trends, and hotspots of COFs in the environmental and energy fields from the perspective of bibliometrics. Herein, based on the Web of Science database, a total of 2589 articles from 2005 to October 6, 2020, were collected. Thereafter, co-occurrence, co-citation analysis, and cluster analysis were conducted using CiteSpace and VOSviewer software. The results indicated that COFs research shows the characteristics of rapid growth. The active countries were mainly USA, Germany, Japan, China, and India. More than half of the top 20 active institutions were from China. The research hotspots in this field were systematically elaborated, including synthesis, adsorption, catalysis, membrane, sensor, and energy storage. Research has shown that various COFs are reasonably designed, synthesized, and used in different applications. For example, when COFs are used for photocatalysis, groups containing photocatalytic active sites are integrated into COFs to improve photocatalytic activity. Finally, some challenges were proposed, that are beneficial to the rapid and balanced development of the COFs field. For instance, the preparation methods still need to be further improved for mass production and there is an imbalance in environmental applications such as fewer sensor and mem-brane applications. We believe that this study provides a comprehensive and systematic overview of the environ-mental and energy applications of COFs for future investigations. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

Covalent organic frameworks (COFs) have garnered extensive attention in the environmental and energy fields due to their low density, adjustable structure, functionalization, and stability. Research on COFs shows rapid growth, with active countries including USA, Germany, Japan, China, and India. Research hotspots include synthesis, adsorption, catalysis, membrane, sensor, and energy storage, with challenges such as improving preparation methods for mass production and addressing the imbalance in environmental applications.