Abstract: Geopolymers made from fly ash provide a promising alternative to ordinary Portland cement, with significant reductions in associated carbon emissions and the potential for developing high-value-added and green products from fly ash. In the past 10 years, nearly 6 000 articles have been published in the field of fly ash-based geopolymers, and it is necessary to conduct a quantitative analysis by scientometric methods to provide a reference for the research of fly ash-based geopolymers and the green integrated utilization of fly ash. This review used scientometric methods to analyze literatures from the Web of Science Core Collection and the China National Knowledge Infrastructure repository to gain insights into the research trends and hotspots of fly ash-based geopolymers. We conducted CiteSpace-based author and institution analyses and constructed a co-occurrence network to examine "fly ash" and "geopolymer" research. Our findings indicated that the number of publications on fly ash-based geopolymers increased yearly from 2013 to 2023, with sustained research interest. The core authors in Chinese and English literature publications accounted for more than 5% of respective publication frequencies. Institutions collaborated more closely in English literature than in Chinese literature. Keywords co-occurrence mapping, clustering, and emergence analyses suggested that recent research on fly ash-based geopolymers had focused on mechanical and adsorption properties, including the trapping of CO₂ and the removal of nutrients, heavy metals, and organic matter from water bodies. The chemical composition of the reaction system is the main factor that distinguishes the mechanical and adsorption properties of fly ash-based geopolymers from other geopolymers. Using chemical composition to regulate the mechanical and adsorption properties synergistically is a major trend for future research.

Key words: geopolymer, fly ash, research trend, research hotspot, mechanical property, adsorption property, CiteSpace