The multidisciplinary science of applied clay research: A 2021–2023 bibliographic analysis

Clay minerals are functional materials that are increasingly used to develop a diverse range of new applications. An overview of current applied clay research can be obtained by analyzing available bibliographic databases to identify present-day research fields and current trends. Using the Web of Science® and software like EndNote™, Bibliometrix, and "R" (v4.3.1) to investigate i) the topics of published studies, ii) author collaborations, and iii) keyword networks, important information matrices can be identified for the core clay journals and more general multidisciplinary periodicals. After initial screening and filtering, 8815 applied clay articles were selected from 2021 to 2023, and nearly 4178 items from ten years back (2011−2013). A step-by-step method of dataset quality control and sorting revealed that clay terms related to adsorbents (34%) and composite material formation (over ∼55%) were the most common in recent years. Composite materials were frequently researched for catalyst support, sensors, coatings, preservatives, foundry, drilling fluids, geotechnical barriers, fertilizers, animal feed and drug delivery. Environmental remediation had the highest presence among adsorption and catalysis of contaminants, in particular, from wastewater and other aqueous medium. Smectite, kaolinite, and halloysite continue to be the most researched minerals in applied clay science. Among these, halloysite has gained significant popularity over the last ten years, particularly for catalytic support, drug delivery, and capture and storage of energy and CO2. The number of applied clay research articles has doubled in the last decade due to increased contributions, especially from China, Brazil, and India. The doubling of multidisciplinary journals has not weakened core clay journals, with Applied Clay Science still publishing the most papers. This bibliographic analysis provides comprehensive search criteria that the clay community can use to explore deeper into current trends in applied clay research and also reapply it in future assessments.