Ridha Djellabi is a chemist with interests and expertise in processes and systems for sustainable environmental remediation and energy generation. Specifically, his research topics focus on solar processes (photocatalysis and photothermal), cavitation (ultrasound), nanomaterials, biomass valorization, solar steam generation, solar seawater desalination, green hydrogen production, solar reactors, LCA, photoelectrochemistry, advanced oxidation processes and so on. He is ranked one of the World’s Top 2 % Scientists issued by Stanford University & Elsevier since 2022. Ridha received his PhD from Badji-Mokhtar University (Annaba, Algeria) in Analytical Chemistry and Environment. A Part of his thesis was conducted at the University of Milan, Italy. He carried out a postdoc at LSRE- University of Porto, Portugal. After that, Ridha worked at RCEES, Chinese Academy of Sciences (Beijing, China) and Shenzhen University (China). Then, he worked as researcher at the University of Milan, Italy. Ridha worked as Personal Docent i Investigador at Universitat Rovira I Virgili, Tarragona in Spain. Currently, Ridha is assistant professor of chemistry at Alfaisal University (Saudi Arabia). He co-authored more than 120 scientific publications, patent and several book chapters. He is associated Editor at Springer Nature. He edited many SI in different journals.