As a photocatalyst, titanium dioxide (TiO2) suffers from the wide band gap and the quick carrier recombination process, thus leading to the inefficient use of solar energy and poor catalytic performance. Herein, in this work, TiO2/Ti3C2 heterojunctions are designed to overcome these shortcomings via growing TiO2 in situ on the titanium element of Ti3C2 MXene. The TiO2/Ti3C2 heterojunctions not only broaden the range of light absorption, but also hugely extend the lifetime of photogenerated carriers. Besides, the anatase TiO2 with exposed (001) facets further enhances the catalytic properties. After optimizing the amount of TiO2/Ti3C2 heterojunctions by controlling reaction time, 20 mg catalysts can degrade 97.6% of 30 mL tetracycline solution (15 mg/L) in 90 min under visible light. Even after five cycles, the degradation ability of TiO2/Ti3C2 only changes from 97.6% to 94.3%. This paper offers another perspective on the synthesis of efficient and stable photocatalysts.