This research work introduces emerging two-dimensional (2D) MXene (Ti3C2) and Therminol55 oil-based mono and hybrid nanofluids for concentrated photovoltaic/thermal (CPV/T) solar systems. This study focuses on the experimental formulation, characterization of properties, and performance evaluation of the nanofluid-based CPV/T system. Thermo-physical (conductivity, viscosity, and rheology), optical (UV-vis and FT-IR), and stability (Zeta potential and TGA) properties of the formulated nanofluids are characterized at 0.025 wt. to 0.125 wt. concentrations of dispersed particles using experimental analysis. By suspending the nanomaterials, photo-thermal energy conversion is improved considerably, up to 85.98. The thermal conductivity of pure oil is increased by adding Ti3C2 and CuO nanomaterials. The highest enhancements of up to 84.55 and 80.03 are observed for the TH-55/Ti3C2 and TH-55/Ti3C2 + CuO nanofluids, respectively. Furthermore, dynamic viscosity decreased dramatically over the temperature range investigated (25°C-105°C), and the nanofluid exhibited dominant Newtonian flow behavior as viscosity remained nearly constant up to a shear rate of 100 s�1. Numerical simulations of the experimentally evaluated nanofluids are performed to evaluate the effect on a CPV/T collector using a three-dimensional transient model. The numerical analysis revealed significant improvements in thermal and electrical energy conversion performance, as well as cooling effects. At a concentrated solar irradiance of 5000 W/m2 and an optimal flow rate of 3 L/min, the highest thermal and electrical energy conversion efficiency enhancements are found to be 12.8 and 2, respectively. © 2022 John Wiley & Sons Ltd.