Titanium dioxide (TiO₂) nanoparticles were reported as a photocatalyst for hydrogen production via water splitting. Herein, two-dimensional (2D) copper (Cu)-terephthalate (CuTPA) metal-organic framework (MOF) and its carbonized products were used as cocatalysts to promote the photocatalytic activity of TiO₂. The materials showed great potential in low-cost and high photocatalytic performance. They offered an environmentally friendly system for hydrogen production with initial and cumulative hydrogen generation rates (HGRs) of 12.8–23.6 mmol·h⁻¹·g⁻¹ and 61.5–112.9 mmol·g⁻¹, respectively. The effects of cocatalyst loading, composite, and carbonization temperature (400 °C, 600 °C, and 800 °C) were investigated. The highest initial and cumulative HGR values were observed for CuO@C obtained after carbonization at 400 °C with 3 wt% loadings, offering HGR values of 23.6 mmol·h⁻¹·g⁻¹ and 112.9 mmol·g⁻¹. CuO@C enhanced the photocatalytic performance of pristine TiO₂ by 295 and 182 folds. The combination effect of CuO and carbon nanosheet is crucial for the high photocatalytic performance of the composite cocatalyst compared to the individual cocatalysts of CuO or carbon.