Ray's research topics cover a diverse set of organic contaminants related investigations. He is interested in understanding how to remove trace organic contaminants using advanced oxidation technologies, how to develop different modelling tools to predict radical reactivity, and how organic contaminants are accumulated in aquatic organisms. He teaches courses that echo these interests. Ray is among the world's top 100000 scientists. He has published more than 100 SCI papers in various journals. There are 18 papers selected as ESI (Essential Science Indicator) 1% highly cited papers, 3 as ESI 0.1% hot papers, 1 as top 10 highly cited paper in International Journal of Quantum Chemistry, and 1 as top 10 highly cited paper in Current Opinion in Chemical Engineering. His h-index is 45 (Google Scholar). He was awarded for excellent reviewers for Water Research, Environmental International, Chemical Engineering Journal, Journal of Hazardous Materials, Science of the Total Environment, Chemosphere, Environmental Science: Process & Impact, and Water, Air & Soil Pollution. He also severs as associate editor for Environmental Chemistry Letters (IF = 7.36), editorial board for Chemical Engineering Journal (IF = 10.6), Process Safety and Environmental Protection (IF=4.96), Scientific Reports (IF=3.98), and Journal of Hunan University.