Increasing the surface area and active sites of adsorbent for hexavalent chromium removal in water is considered an effective and efficient way to enhance reduction and adsorption performance. Here 2D/0D heterojunction of Ti3C2 MXenes/TiO2 nanoparticles with different amounts of TiO2 were synthesized using a one-step hydrothermal method and the reduction and adsorption of Cr (VI) at different pH values of composite material were analyzed. The results show that the Ti3C2/TiO2 composite material allows significantly enhanced removal ability of toxic Cr (VI) in water, compared to pure Ti3C2 nanosheets. The effective removal of Cr (VI) in water was 99.35%. The Ti3C2/TiO2 composite can not only rapidly and efficiently remove Cr (VI) from potassium dichromate solution by reducing Cr (VI) to Cr (III), but simultaneously adsorbs the reduced Cr (III). Therefore, the 2D/0D heterojunction of Ti3C2 MXenes/TiO2 nanoparticles has potential application prospects in the reduction adsorption of Cr (VI).