TiO₂ has been everlastingly employed as popular photocatalyst for water splitting. However, the wide band gap (3.0–3.2 eV) and poor absorption to visible light of TiO₂ result in a low utilization of solar energy and limit its large-scale application. To decrease its band gap and promote the utilization of full solar energy, we here modified TiO₂ by in situ growth of N-rich covalent organic polymer (termed as COP_HM). During the in situ growth of COP_HM on the surface of TiO₂, intimate contacts between TiO₂ and COP_HM were built and core-shell structures were finally formed. The derived TiO₂@COP_HM demonstrated a narrower band gap (2.53 eV) compared to raw TiO₂ (3.13 eV) and improved absorption to visible light. The optimal TiO₂@COP_HM hybrid exhibited excellent hydrogen evolution performance of 162.7 μmol h⁻¹ under simulated sunlight which was more than 3 times higher than raw TiO₂ (51.3 μmol h⁻¹). Particularly, visible light hydrogen evolution rate of TiO₂@COP_HM reached 0.65 μmol h⁻¹ while non-hydrogen generation was observed using raw TiO₂.

TiO ₂一直被用作流行的水分解光催化剂。_{然而，TiO 2}的宽带隙(3.0-3.2 eV)和对可见光的吸收差导致太阳能利用率低，限制了其大规模应用。为了减小其带隙并促进充分利用太阳能，我们在这里通过原位生长富氮共价有机聚合物（称为 COP _HM）来改性 TiO _{2 。}在COP _{HM在TiO 2}表面原位生长的过程中，TiO ₂和COP _HM之间建立了紧密接触，最终形成了核-壳结构。衍生的 TiO ₂ @COP _{HM与原始 TiO 2} (3.13 eV ) 相比，显示出更窄的带隙 (2.53 eV ) 并改善了对可见光的吸收。最佳的 TiO ₂ @COP _{HM杂化物在模拟阳光下表现出 162.7 μmol h} ^-1的优异析氢性能，比原始 TiO ₂（51.3 μmol h ^-1 ）高出 3 倍以上。_{特别地，TiO 2} @COP _HM的可见光析氢速率达到0.65μmol h ^{-1而使用原始TiO} ₂观察到非氢生成。