New alternative routes to traditional Fischer-Tropsch Synthesis (FTS) must be established to get a more efficient process from the point of view of energy and sustainability. Solar photocatalytic-assisted FTS is a promising new path to obtain fuels from renewable resources. However, proper photocatalysts must be designed to enhance the photocatalytic activity under solar/visible radiation. In this work, Fe and Co-doped TiO₂ catalysts were synthesized by a traditional impregnated method and by a hydrothermal route. The oxygen vacancies generation on TiO₂ photocatalysts was studied by Raman, XPS and Diffuse Reflectance Spectroscopy (DRS) and correlated with the decrease of the band gap and the photoactivity in the syngas conversion into solar fuels under solar radiation. Metal doping and H₂ reduction treatment favour the oxygen vacancies generation that decreases the band gap from 3.3 eV for P25 to values as low as 2.2 and 2.5 eV for Fe- and Co-doped TiO₂. This lower band gap increases the methanation activity under solar radiation. Moreover, this metal doping does not only affect the band gap and CO methanation activity under solar radiation but also the CC coupling, favouring the production of ethanol. Thus, in presence of P25, only CO₂ and CH₄ are obtained whereas the addition of Fe and Co enhances the CH₄ generation and favours ethanol production. Therefore, the present work opens new opportunities for the photocatalytic Fischer-Tropsch conversion (PFTS) of crude syngas, which can be obtained from biomass or MSW gasification, into fuels under solar light.

从能源和可持续性的角度来看，必须建立传统费托合成 (FTS) 的新替代途径，以获得更有效的过程。太阳能光催化辅助 FTS 是从可再生资源中获取燃料的一条有前途的新途径。然而，必须设计合适的光催化剂以增强在太阳/可见光辐射下的光催化活性。在这项工作中，Fe和Co掺杂的TiO ₂催化剂是通过传统的浸渍法和水热法合成的。TiO ₂上氧空位的产生通过拉曼、XPS 和漫反射光谱 (DRS) 研究了光催化剂，并将其与带隙的减小和在太阳辐射下合成气转化为太阳能燃料的光活性相关联。金属掺杂和 H ₂还原处理有利于氧空位的产生，将带隙从 P25 的 3.3 eV 降低到 Fe 和 Co 掺杂的 TiO _{2 的}低至 2.2 和 2.5 eV 的值。这种较低的带隙增加了太阳辐射下的甲烷化活动。此外，这种金属掺杂不仅会影响太阳辐射下的带隙和 CO 甲烷化活性，还会影响 CC耦合，有利于乙醇的生产。因此，在 P25 存在下，只有 CO ₂和 CH ₄获得，而 Fe 和 Co 的添加增强了 CH _{4 的}生成并有利于乙醇的生产。因此，目前的工作为粗合成气的光催化费托转化 (PFTS) 开辟了新的机会，粗合成气可以从生物质或 MSW 气化中获得，在太阳光下转化为燃料。