Abstract

Leather tanning is a key process that stabilizes collagen fibres and determines the hydrothermal stability, durability, microbial resistance, and end-use performance of leather. However, conventional tanning, particularly chrome tanning, is associated with substantial resource consumption and environmental pressure, including the discharge of chromium-containing wastewater, high-salinity effluents, sludge, and other pollutants. In order to systematically reveal the knowledge structure, research hotspots, and evolutionary trends in tanning technology, this study retrieved literature related to leather tanning technologies from the Web of Science Core Collection for the period 2000–2025. After screening, 2,829 valid records were analyzed using CiteSpace 6.3.R1 and Excel. The results show that research output in this field has increased significantly, with annual publications rising from 34 in 2000 to 215 in 2024, indicating sustained academic attention. China, India, Spain, the United States, Italy, Brazil, and Turkey are major contributors, while institutions such as CSIR–India, the Central Leather Research Institute, Sichuan University, and Shaanxi University of Science & Technology constitute the core research forces. Keyword co-occurrence, clustering, timeline, and burst analyses indicate that the field has evolved from traditional chrome tanning optimization and end-of-pipe pollution control toward cleaner production, chrome-free and low-chrome tanning, nanomaterial-assisted treatment, bio-based tanning agents, process intensification, and circular economy strategies. The findings suggest that future research should focus on systematic green tanning process design, multi-scale mechanistic characterization, closed-loop recycling of chromium and collagen resources, life-cycle assessment, and interdisciplinary international collaboration. This study provides a bibliometric reference for understanding the development trajectory of tanning technologies and for promoting the sustainable transformation of the leather industry.