This paper conducts a new investigation of air purification with total heat recovery based on nanofluids for the first time to realize the synergistic application of nanofluids to the heat and mass transfer as well as the photocatalysis and sterilization fields. To explore the feasibility of the new application, the stable TiO2 nanofluids were obtained by a post-treated optimized preparation method. Then the experimental device is built to investigate the formaldehyde and total volatile organic compounds (TVOC) purification as well as sterilization. At last, the heat recovery characteristics of nanofluids are indirectly investigated by testing the gas-liquid bubbling heat transfer behaviour. The results show the post-treated method can improve the dispersion stability of nanofluids. The nanofluid system has efficient effects on air purification and sterilization for both fungi and bacteria. The nanofluids have higher gas-liquid bubbling heat transfer performance than water which increased as the particle loading. (C) 2019 Elsevier B.V. All rights reserved.