Environmental nanotechnology is considered to play a key role in shaping current environmental engineering and science. Looking at the nanoscale has stimulated the development and use of novel and cost-effective technologies for catalytic degradation, adsorptive removal and detection of contaminants as well as other environmental concerns. Polymer-based nanocomposites (PNCs), which incorporate advantages of both nanoparticles and polymers, have received increasing attention in both academia and industry. They present outstanding mechanical properties and compatibility owing to their polymer matrix, the unique physical and chemical properties caused by the unusually large surface area to volume ratios and high interfacial reactivity of the nanofillers. In addition, the composites provide an effective approach to overcome the bottleneck problems of nanoparticles in practice such as separation and reuse. This article gives an overview of PNCs for environment application. A brief summary of the fabrication methods of PNCs is provided, and recent advances on the application of PNC materials for treatment of contaminants, pollutant sensing and detection and green chemistry are highlighted. In addition, the research trends and prospective in the coming future are briefly discussed. (C) 2011 Elsevier B.V. All rights reserved.