Developing efficient photocatalysts with highly active facets and appropriate cocatalyst hybridization to form heterostructure is a valid way to expedite the separation of photoexcited electron-hole pairs. Herein, a novel 0D/1D Ti3C2Tx MXene/TiO2 photocatalyst was fabricated for photoelectrochemical (PEC) water splitting and tetracycline antibiotic photocatalytic degradation. Meanwhile, highly-exposed TiO2 nanotube arrays were prepared by electrochemical anodizing method, and Ti3C2Tx nanoparticles with mixed terminal group were uniformly grown on the surface of TiO2 through the hydrothermal and solvothermal process, respectively. Compared with pure TiO2, the Ti3C2Tx/TiO2 heterostructure exhibited different degrees of enhancement in PEC and photocatalytic degradation activities under simulated sunlight. The TNT/M-h sample yielded a photocurrent density of 1.77 mA cm−2 at 0 V (vs. SCE) and achieved a 95.57 % photocatalytic removal rate of tetracycline within 140 min. The excellent performance originated from the strong interfacial contact and work function discrepancy between the ordered tubular structure of TiO2 and 0D Ti3C2Tx nanoparticles, which realized the high-efficiency photogeneration and transfer of electron-hole pairs.