Реферат: Carbon xerogels (CXs) are materials obtained via the pyrolysis of resins prepared via the sol–gel polycondensation of resorcinol and formaldehyde. These materials attract great attention as adsorbents, catalyst supports, and energy storage materials. One of the most interesting features of CXs is the possibility of fine-tuning their structures and textures by changing the synthesis conditions in the sol–gel stage. Thus, the first part of this review is devoted to the processes taking place in the polycondensation stage of organic precursors. The formation of hydroxymethyl derivatives of resorcinol and their polycondensation take place at this stage. Both of these processes are catalyzed by acids or bases. It is revealed that the sol–gel synthesis conditions, such as pH, the formaldehyde/resorcinol ratio, concentration, and the type of basic modifier, all affect the texture of the materials being prepared. The variation in these parameters allows one to obtain CXs with pore sizes ranging from 2–3 nm to 100–200 nm. The possibility of using other precursors for the preparation of organic aerogels is examined as well. For instance, if phenol is used instead of resorcinol, the capabilities of the sol–gel method become rather limited. At the same time, other phenolic compounds can be applied with great efficiency. The methods of gel drying and the pyrolysis conditions are also reviewed. Another important aspect analyzed within this review is the surface modification of CXs by introducing various functional groups and heteroatoms. It is shown that compounds containing nitrogen, sulfur, boron, or phosphorus can be introduced at the polycondensation stage to incorporate these elements into the gel structure. Thus, the highest surface amount of nitrogen (6–11 at%) was achieved in the case of the polycondensation of formaldehyde with melamine and hydroxyaniline. Finally, the methods of preparing metal-doped CXs are overviewed. Special attention is paid to the introduction of a metal precursor in the gelation step. The elements of the iron subgroup (Fe, Ni, Co) were found to catalyze carbon graphitization. Therefore, their introduction can be useful for enhancing the electrochemical properties of CXs. However, since the metal surface is often covered by carbon, such materials are poorly applicable to conventional catalytic processes. In summary, the applications of CXs and metal-doped CXs are briefly mentioned. Among the promising application areas, Li-ion batteries, supercapacitors, fuel cells, and adsorbents are of special interest.

Библиографическая ссылка: Veselov G.B. , Vedyagin A.A.
Resorcinol–Formaldehyde-Derived Carbon Xerogels: Preparation, Functionalization, and Application Aspects
Materials. 2023. V.16. N19. 6566 :1-32. DOI: 10.3390/ma16196566 WOS Scopus РИНЦ CAPlus PMID OpenAlex

Даты:

Поступила в редакцию:	27 авг. 2023 г.
Принята к публикации:	3 окт. 2023 г.
Опубликована в печати:	5 окт. 2023 г.
Опубликована online:	5 окт. 2023 г.

Идентификаторы БД:

Web of science:	WOS:001086102300001
Scopus:	2-s2.0-85174005197
РИНЦ:	55253283
Chemical Abstracts:	2023:2132466
PMID (PubMed):	37834703
OpenAlex:	W4387405841

Цитирование в БД:

БД	Цитирований
OpenAlex	14
Scopus	13
Web of science	13
РИНЦ	3

Альметрики: