Global Research Trends in Catalysis for Green Hydrogen Production from Wastewater: A Bibliometric Study (2010–2024)

By turning a waste stream into a clean energy source, green hydrogen generation from wastewater provides a dual solution to energy and environmental problems. This study presents a thorough bibliometric analysis of research trends in the field of green hydrogen generation from wastewater between 2010 and 2024. A total of 221 publications were extracted from Scopus database, and VOSviewer (1.6.20) was used as a visualization tool to identify influential authors, institutions, collaborations, and thematic focus areas. The analysis revealed a significant increase in research output, with a peak of 122 publications in 2024, with a total of 705 citations. China had the most contributions with 60 publications, followed by India (30) and South Korea (26), indicating substantial regional involvement in Asia. Keyword co-occurrence and coauthorship network mapping revealed 779 distinct keywords grouped around key themes like electrolysis, hydrogen evolution reactions, and wastewater treatment. Significantly, this work was supported by contributions from 115 publication venues, with the International Journal of Hydrogen Energy emerging as the most active and cited source (40 articles, 539 citations). The multidisciplinary aspect of the area was highlighted by keyword co-occurrence analysis, which identified recurring themes including electrolysis, wastewater treatment, and hydrogen evolution processes. Interestingly, the most-cited study garnered 131 citations and discussed the availability of unconventional water sources for electrolysis. Although there is growing interest in the field, it is still in its initial phases, indicating a need for additional research, particularly in developing countries. This work offers a basic overview for researchers and policymakers who are focused on promoting the sustainable generation of green hydrogen from wastewater.