Introduction
The Circular Economy (CE) challenges the linear “take–make–dispose” model by promoting efficiency, waste reduction, and systemic restoration. Over the past two decades, CE has gained global prominence as a sustainability framework addressing resource scarcity, environmental degradation, and climate change. Scholars view CE as a paradigm shift capable of decoupling growth from resource use by extending product lifecycles and fostering restorative systems. Despite attention, CE literature remains conceptually diverse, with over 100 definitions emphasizing design, resource management, policy, or technology. This diversity creates ambiguity for policymakers and practitioners. The present study provides a scientometric analysis of CE literature to identify publication trends, geographical distribution, conceptual clusters, thematic evolution, and key drivers shaping CE research. "It aims to answer the question: 'What are the conceptual trends, core themes, and key developments in the Circular Economy'?.

Methodology
A scientometric approach was applied to CE publications indexed in Web of Science (WoS). The query (“circular economy” OR “circular economies”) yielded 9910 records from 2000–2025. After removing duplicates, the dataset was analyzed using Bibliometrix/Biblioshiny, CiteSpace, and thematic mapping. Techniques included co-word occurrence, keyword clustering, thematic visualization, and temporal evolution tracking. Centrality and density indices identified motor, basic, niche, and emerging themes. This ensured validity and reproducibility, offering a systematic depiction of CE research trends

Findings
CE research output increased sharply after 2017. Between 2013–2016, publications were stable, but growth accelerated from 2017 onward. The peak occurred in 2020–2022, with over 75% of total publications released between 2018–2024. The apparent decline in 2025 reflects incomplete data. This expansion coincides with global adoption of circular policies, industrial demand for resource-efficient models, and integration with Industry 4.0 technologies. China leads CE research, embedding CE in national five-year plans since 2005. Between 2010–2015, output surged in waste management, recycling, and governance. By 2020, China dominated the field. The United States follows, focusing on innovation and business models. In Europe, the UK emphasizes policy, Germany resource efficiency and recycling, and Italy product design and sustainable value chains. Co-word analysis reveals CE as a hub connecting multiple streams: Environmental/ operational: waste management, recycling, resource efficiency, life cycle assessment. Systemic/institutional: sustainability, policy, governance, barriers. Technological: Industry 4.0, digitalization, blockchain, IoT. Managerial/business: circular business models, reverse logistics, supply chains. Emerging clusters include bioeconomy, anaerobic digestion, food waste, and resource recovery. Thematic mapping identifies “circular economy management” and “waste management” as motor themes. Basic themes (sustainability frameworks, barriers) provide grounding. Niche themes (anaerobic digestion, biochar) are technologically relevant but peripheral. Emerging themes (food waste, biomass) signal growing interest. From 2000–2019, CE literature emphasized industrial ecology, resource reuse, and biotechnologies. Between 2020–2021, focus shifted to measurement, policy integration, and renewable energy. From 2022–2024, integration with digital technologies, business models, climate change mitigation, and SDGs became prominent. Peripheral clusters (biochar, biorefineries) linked with digitalization and business innovations. This reflects a shift from narrow environmental focus to systemic, interdisciplinary approaches. Cluster analysis shows CE research structured around: Central cluster: circular supply chains, forming the theoretical and operational core. Adjacent clusters: Industry 4.0/digital technologies, sustainable development/policy, business/consumer behavior. Peripheral clusters: anaerobic digestion, waste management, plastics recycling. Proximity of clusters highlights CE as an integrated ecosystem connecting technology, policy, and resource management.

Discussion and Conclusion
CE research follows two converging paths: Established themes: waste management, recycling, industrial ecology & Emerging themes: business models, digitalization, Industry 4.0. Specialized subdomains (anaerobic digestion, bioeconomy) support broader frameworks. CE has evolved from an environmental initiative to a systemic paradigm encompassing value chains, innovation, and governance. Country-specific insights show Iran faces barriers such as weak infrastructure, fragmented regulation, and limited coordination. Yet initiatives like eco-industrial parks and circular supply chains offer pathways. CE adoption can reduce emissions, improve energy efficiency, and create green jobs, supporting national and global sustainability goals. This study provides a replicable map of CE literature, emphasizing its multidimensional transformation. CE now integrates operational, managerial, technological, and policy streams, reflecting a trajectory toward holistic applications. Key drivers include policy and managerial themes, integration of measurement frameworks with business and digital innovations, and specialized biotechnological domains. For Iran, coherent strategies, supportive policies, and alignment of social, economic, and environmental goals are essential. Future research should explore financial instruments, under-researched service sectors, consumer awareness, and comparative policy analyses to consolidate CE knowledge and support global adoption.