The modulating degree of defect and graphitization carbon coupled metal oxide composite is extremely important because these materials have been applied in various fatal fields, especially in energy storage/conversion and catalysis. Herein, we reported the in situ formation of long defect-rich nitrogen-doped carbon nanotubes (NCNTs) coupled with a porous TiO₂@NC composite (TiO₂@NC–NCNTs) derived from spindle-type bimetallic (Ti/Co) MOF microrods. Thanks to the rational composition and unique structure, the as-prepared Pt/TiO₂@NC–NCNTs-7 can be used as a bifunctional fuel cell electrocatalyst. For MOR, the optimized catalyst exhibits superior mass activity of 577 mA mg_Pt^–1 (in acidic medium) and 3100 mA mg_Pt^–1 (in alkaline medium), which is 2.02 and 4.08 times superior than the commercial Pt/C catalyst, and shows excellent CO tolerance and better cyclic stability. This state-of-the-art nanocatalyst also exhibits a more positive onset potential (1.01 V) and upper limiting current density (5.03 mA cm^–2) than commercial Pt/C (0.96 V and 4.75 mA cm^–2) toward oxygen reduction reaction. The optimized degree of defect and graphitization in N-doped carbon (including NC and NCNTs) of the nanocatalyst not only provides large amounts of active sites to Pt NP deposition but also is positive for the charge transfer improvement of the overall nanocatalyst. The strong-coupled Pt–NCNTs(NC)–TiO₂ can further boost the catalytic activity and CO-tolerance. This work not only opens a new approach to develop a novel carbon/metal oxide composite with the desired morphology and properties but also provides new insights into the design and construction of state-of-the-art nanomaterials for fuel cells, water splitting, and photocatalysis.

中文翻译：

---

像主轴一样的MOF衍生的TiO ₂ @ NC-NCNTs复合材料，具有调节缺陷位点和石墨化纳米约束Pt NPs作为优良的双功能燃料电池电催化剂

缺陷和石墨化碳偶联金属氧化物复合材料的调制度极为重要，因为这些材料已应用于各种致命领域，尤其是在能量存储/转化和催化领域。在这里，我们报道了原位形成长缺陷的富氮掺杂碳纳米管（NCNTs）与衍生自纺锤型双金属（Ti / Co）MOF的多孔TiO ₂ @NC复合材料（TiO ₂ @ NC–NCNTs）微棒。由于其合理的组成和独特的结构，所制备的Pt / TiO ₂ @ NC-NCNTs-7可用作双功能燃料电池电催化剂。对于MOR，优化的催化剂表现出出色的质量活性，为577 mA mg _Pt ^–1（在酸性介质中）和3100 mA mg _Pt^–1（在碱性介质中），比市售Pt / C催化剂高出2.02和4.08倍，并具有出色的CO耐受性和更好的循环稳定性。与商用Pt / C（0.96 V和4.75 mA cm ^–2）相比，这种最先进的纳米催化剂还显示出更高的起始电位（1.01 V）和上限电流密度（5.03 mA cm ^–2）。反应。纳米催化剂的N掺杂碳（包括NC和NCNT）中缺陷和石墨化的最佳程度，不仅为Pt NP沉积提供了大量的活性位点，而且对于改善整个纳米催化剂的电荷转移也具有积极意义。强耦合Pt-NCNTs（NC）-TiO ₂可以进一步提高催化活性和CO耐受性。这项工作不仅为开发具有所需形态和性能的新型碳/金属氧化物复合材料开辟了新途径，而且还为燃料电池，水分解和分离技术的最新纳米材料的设计和构造提供了新见识。光催化。