The role of hydroxyl-functionalization of reduced TiO₂ (Blue TiO₂) for the photocatalytic oxidation of toxic NOx was systematically explored in the present study. A hydrogenation technique was used to reduce the rutile phase in P25 TiO₂ giving rise to a Magneli phase. Then, the process was followed by the surface functionalization of the Blue TiO₂ with Trimethoxy (Propyl) Silane (TPS). The fabricated nanoparticles were structurally characterized, and photocatalytically tested for NOx abatement. OH-functionalized Blue TiO₂ showed strong photo-oxidation of NOx with NOx removal efficiency of 80.2%. The broad-band light absorption (UV and visible) and the formation of a higher number of radicals on the surface of OH-functionalized Blue TiO₂ made the material more efficient than other samples. In addition, the lowest NO₂ selectivity of 2.7% proved the effective suppression of toxic NO₂ and formation of nitrate ions. The reusability test was carried out for five cycles of 1 ​h and had 10% loss in NOx removal efficiency. The role of surface OH groups for the oxidation of NO and NO₂ has been discussed in this manuscript. A possible mechanism for NOx photo-oxidation is proposed based on FTIR, ESR, and ion chromatography test.

在本研究中，系统地研究了还原的TiO ₂（Blue TiO ₂）的羟基官能化对有毒NOx的光催化氧化的作用。使用氢化技术来还原P25 TiO _2中的金红石相，从而产生马涅利相。然后，该过程之后是用三甲氧基（丙基）硅烷（TPS）对蓝色TiO ₂进行表面功能化。对制成的纳米颗粒进行结构表征，并进行光催化测试以减少NOx。OH-官能化的蓝色TiO ₂表现出强烈的NOx光氧化作用，NOx去除率为80.2％。宽带光吸收（紫外线和可见光）以及在OH-官能化的蓝色TiO ₂的表面上形成更多的自由基，使得该材料比其他样品更有效。另外，最低的NO ₂选择性为2.7％，证明有效抑制了有毒的NO ₂和硝酸根离子的形成。可重复使用性测试进行了1小时的五个循环，并且NOx去除效率损失了10％。该手稿中讨论了表面OH基团对NO和NO ₂氧化的作用。基于FTIR，ESR和离子色谱测试，提出了一种可能的NOx光氧化机理。