The effective utilization of solar energy contributes to addressing the energy issues of society. The proposition of PV/T realizes the comprehensive utilization of photovoltaic and photothermal energy. However, the conventional water-based photovoltaic/thermal (PV/T) system encounters some issues, such as low heat exchange, low photo-electrical and photo-thermal conversion efficiency as well as high surface temperature of PV modules in the process of practical application. Therefore, nanofluids are regarded as one of the effective approaches to tackle these problems. This is because the nanoparticles are frequently dispersed into the different base fluids to form nanofluids as the working fluid for ameliorating itself thermal physical properties and applying into the solar PV/T module for the enhancement of heat transfer efficiency. Notably, MXene is a novel two-dimensional nanomaterial that has exhibited wonderful potential in thermal and electrical applications, but there is still lack of research in the solar PV/T module applications. In this study, MXene is introduced into heat transfer fluids and integrated with phase change materials to enhance the PV/T modules efficiency. An experimental test of PV/T module with MXene/water nanofluids with different flow rates is carried out based on an interior light source of solar simulator. Additionally, the MXene nano-enhanced phase change materials on system efficiency are also investigated. Experimental results indicated that the MXene/water nanofluid with a concentration of 0.01 wt% could improve system thermal and electrical efficiencies by 7.89% and 0.57%, respectively, in comparison to pure water. Furthermore, the existence of PCM alleviates the fluctuation of the PV surface temperature, reducing the PV surface temperature by 17.58°C resulting in increasing the electrical efficiency by 4% compared to the PV/T with pure water module.