Surface-functionalized nitrogen/carbon co-doped polymorphic TiO₂ phase junction nanoparticles uniformly distributed in porous carbon matrix were synthesized by a simple one-step pyrolysis of titanium based metal-organic framework (MOF), NH₂-MIL-125(Ti) at 700 °C under water vapour atmosphere. Introducing water vapour during the pyrolysis of NH₂-MIL-125(Ti) not only functionalizes the derived porous carbon matrix with carboxyl groups but also forms additional oxygen-rich N like interstitial/intraband states lying above the valence band of TiO₂ along with the self-doped carbon, which further narrows the energy band gaps of polymorphic TiO₂ nanoparticles that enhance photocatalytic charge transfer efficiency. Without co-catalyst, sample N-C-TiO₂/C_ArW demonstrates H₂ evolution activity of 426 µmol g_cat^-1 h^-1, which remarkably outperforms commercial TiO₂ (P-25) and N-C-TiO₂/C_Ar with a 5-fold and 3-fold H₂ generation, respectively. This study clearly shows that in water vapour atmosphere during the pyrolysis increases the hydrophilicity of the Ti-MOF derived composites by the functionalization of porous carbon matrix with carboxylic groups, significantly enhancing the electrical conductivity and charge transfer efficiency due to the formation of additional localized oxygen-rich N like interstitial/intraband states. This work also demonstrates that by optimizing the anatase-rutile phase composition of the TiO₂ polymorphs, tuning the energy band gaps by N/C co-doping and functionalizing the porous carbon matrix in the N-C-TiO₂/C nanocomposites, the photocatalytic H₂ generation activity can be further enhanced.

通过简单的一步法热解钛基金属-有机骨架（MOF），NH ₂ -MIL-125（Ti），合成了均匀分布在多孔碳基质中的表面官能化氮/碳共掺杂多晶型TiO ₂相结纳米粒子。在700°C的水蒸气气氛下。在NH ₂ -MIL-125（Ti）的热解过程中引入水蒸气不仅使衍生的具有羧基的多孔碳基体功能化，而且还形成了额外的富氧N，如位于TiO ₂价带上方的间隙/带内态以及自掺杂碳，进一步缩小了多晶型TiO ₂的能带隙增强光催化电荷转移效率的纳米颗粒。在没有助催化剂的情况下，样品NC-TiO ₂ / C _ArW表现出426 µmol g _cat ^-1 h ^-1的H _2析出活性，该性能明显优于市售的TiO ₂（P-25）和NC-TiO ₂ / C _Ar。 5倍和3倍H ₂一代。这项研究清楚地表明，在热解过程中的水蒸气气氛中，带有羧基的多孔碳基体官能化可提高Ti-MOF衍生复合材料的亲水性，由于形成了额外的局部氧，从而显着提高了电导率和电荷转移效率像间隙/带内状态一样富含N。这项工作还表明，通过优化TiO ₂多晶型物的锐钛矿-金红石相组成，通过N / C共掺杂来调节能带隙并功能化NC-TiO ₂ / C纳米复合材料中的多孔碳基质，光催化H ₂代活动可以进一步增强。