It is a pleasure to dedicate this special issue of Chinese Journal of Catalysis (CJC) to Dr. Jimmy C. Yu, Choh-Ming Li Professor of Chemistry at The Chinese University of Hong Kong. This is to celebrate the 20^th anniversary of his return to Hong Kong and leading photocatalytic research there. This special issue contains 21 invited papers which were subjected to the review standard of the journal. As Guest Editors, we express our sincere thanks to the authors who contributed to this special issue. We also thank the reviewers for helping to improve the papers, and providing their reviews in a short time. Finally, we would like to thank Dr. Junwang Tang, the Associate Editor-in-Chief for handling the manuscripts. We also want to thank the Editors and the Editorial Office Staff of CJC for their valuable advice and kind assistance for the publication of this special issue.

Professor Jimmy C. Yu was born in Fujian, China and grew up in Hong Kong. He received a B.S. in chemistry from St. Martin’s College in 1980, and a Ph.D. from the University of Idaho in 1985 under the direction of Professor Chien M. Wai. He served as an assistant professor at the University of Puget Sound in 1984, and then taught at the University of Central Missouri from 1985 to 1995. He joined The Chinese University of Hong Kong in 1995 to help establish a multidisciplinary environmental science program. He is now Head of United College, Chairman of the Department of Chemistry, and Associate Director of the Institute of Environment, Energy and Sustainability. Since 2015, he has also held the position of Choh-Ming Li Professor of Chemistry.

Professor Jimmy C. Yu has dedicated his professional life to the many aspects of photocatalytic research. With support from the Research Grants Council, the Innovation and Technology Fund of Hong Kong, and the National Science Foundation of China, he made outstanding progress in the design of novel visible light photocatalytic materials, modification of traditional TiO₂-based photocatalysts, chemical synthesis of advanced photocatalytic materials, and mechanistic studies of the photocatalytic degradation of organic pollutants and energy conversion. In particular, his pioneering works on TiO₂ solid solution photocatalysts, surface fluorination of semiconductor photocatalysts, and mesoporous photocatalytic materials have given new insights for the development of advanced photocatalytic materials. Professor Jimmy C. Yu has published more than 300 research articles and received over 20000 citations. In 2014, he was named Thomson Reuters Highly Cited Researcher in Materials Science. In addition, Professor Yu also worked on the industrialization of photocatalytic technology. The nano- crystalline TiO₂-based coating technology developed by Professor Jimmy C. Yu has been used in products for air purification and high-end water treatment. In his highly decorated career, Professor Jimmy C. Yu has received many distinguished awards and honors, including a 2005 second prize in China’s State Natural Science Award and the 2010 Ministry of Education’s Chang Jiang Chair Professorship.

Dr. Yu is an Associate Editor of the Journal of Nanoparticle Research. He also serves on the Editorial Advisory Boards of Langmuir and Advanced Materials Interfaces, and the Editorial Boards of Environmental Chemistry and Rare Metal.

In addition to his outstanding contributions to photocatalytic research, Professor Yu is also a dedicated and passionate teacher who inspires young people to advance knowledge and strive for excellence in science. In the past twenty years, he has mentored more than 40 graduate students, postdoctoral fellows, and visiting scientists who have gone on to establish successful academic careers. Many of them were chosen as Outstanding/Excellent Youths by the National Natural Science Foundation.

We are delighted to dedicate this special issue to Professor Jimmy C. Yu, and we also wish him happiness on his coming 60^th birthday in 2016.