This is the second volume of a two-volume set book, Electromagnetic Wave Innovations for Sustainability, which explores advancements in electromagnetic technologies like photocatalysis and microwave chemistry for sustainable energy production, recycling, and environmental remediation, within the framework of the SDGs and circular economy.

The second volume focuses on applications of electromagnetic-wave–based technologies that address pressing environmental and energy challenges. It opens with a historical overview of microwave technologies for environmental protection and hybrid microwave–photocatalysis systems for wastewater treatment. The next section explore innovations in recycling technologies, including polymer degradation, plastic-to-monomer conversion, biomass–plastic co-recycling for hydrogen and carbon nanomaterials, and microwave-induced pyrolysis for metal recovery from e‑waste. Further chapters cover advancements in hydrogen production, solar cell development, and CO₂ conversion, followed by microwave- and radiation-based water treatment and environmental remediation strategies. Together with the first volume, this volume provides an integrated perspective on how electromagnetic-wave technologies can accelerate progress toward a sustainable and circular society.

Satoshi Horikoshi received his Ph.D. in 1999 and worked as a postdoctoral researcher at the Frontier Research Center for Global Environmental Science until 2006. He has held positions at several universities and has been a professor at Sophia University since 2020. Currently, he is the president of JEMEA and serves on the editorial advisory board of several international journals. Moreover, he serves on several national committee and boards of scientific society. His research interests include novel functional materials, nanomaterials, catalytic reactions, food science, biology, sustainable energy, environmental protection, data science, beauty/health and circular economy processes using “microwave- and photo-energy sciences”. He has co-authored over 230 publications and contributed to 41 books. He regularly appears on television to explain microwave technology.

 Nick Serpone is a Professor Emeritus (1968-1998) and was a Research Professor (1998-2004) at Concordia University, Montreal, Canada. He was a Contract Professor (winter semesters 2002-2005) and since 2005 a Visiting Professor at the University of Pavia (Italy;). He was also a Visiting Associate Professor at the University of Bologna (1975-1976), Invited Professor at the Ecole Polytechnique Fédérale de Lausanne (1983-1984; Switzerland), Research Director at the Ecole Centrale de Lyon (1990-1991; France), and a Visiting Professor at the University of Ferrara (1997-1998; Italy) as well as at the Tokyo University of Science (Japan) and a Guest Lecturer at the University of Milan (Italy). He was Program Director at the National Science Foundation (1998-2001; Washington, DC, USA) and a consultant to the 3M Company (1986-1996; Saint Paul Minnesota, USA). He has co-edited/co-authored 18 books, contributed 42 chapters to books, and published over 520 articles. His principal interests have focused on the photophysics and photochemistry of coordination compounds and metal-oxide semiconductors, together with Photocatalysis for environmental remediation, and microwave chemistry. He is a Fellow of the European Academy of Sciences (EurASc) and was Head of its Materials Science Division  between 2014 and 2020. In collaboration with Prof. Leonardo Palmisano of the University of Palermo (Italy) he has recently co-authored a General Chemistry Textbook titled “CHEMISTRY – Understanding Fundamentals and Principles” for advanced College Undergraduates.