Several NiO/TiO₂ composites fabricated by the impregnation method were employed as photocatalysts for the photoreduction of gaseous CO₂ in this study. The characterizations of fabricated photocatalysts were observed by XRD, FE-SEM, EDS, N₂ adsorption-desorption, and UV–vis spectroscopy. The distribution of Ni, Ti, and O atoms on the surface of these photocatalysts was demonstrated to be uniform, and the BET surface areas were varied slightly with the increase of NiO loading. Meanwhile, the absorption edge of fabricated photocatalysts was found to shift towards the visible region and the bandgap energy was decreased. The photocatalytic reaction was conducted in a continuous-flow reactor under UV irradiation. Methane was identified to be the main product and produced in the order: 10 wt% NiO/TiO₂ > TiO₂ > 20 wt% NiO/TiO₂. The maximum methane yield reached at 4.69 mmol/g_catalyst over 10 wt% NiO/TiO₂ and was twice higher than that of P-25. The formation of p-n junction significantly improved the photocatalytic activity of P-25. Furthermore, the proposed schematic diagram for photocatalytic CO₂ reduction in the gaseous phase under NiO-TiO₂ / UV process was introduced.

在本研究中，采用浸渍法制备的几种 NiO/TiO ₂复合材料作为光催化剂用于气态 CO _{2 的}光还原。通过XRD、FE-SEM、EDS、N ₂观察制备的光催化剂的表征吸附-解吸和紫外-可见光谱。Ni、Ti和O原子在这些光催化剂表面的分布被证明是均匀的，随着NiO负载量的增加，BET表面积略有变化。同时，发现制备的光催化剂的吸收边向可见光区移动，带隙能量降低。光催化反应在连续流动反应器中在紫外线照射下进行。甲烷被确定为主要产物，其生产顺序为：10 wt% NiO/TiO ₂ > TiO ₂ > 20 wt% NiO/TiO ₂。最大甲烷产率达到 4.69 mmol/g_催化剂超过 10 wt% NiO/TiO ₂并且比_催化剂高两倍P -25。p - n结的形成显着提高了P- 25的光催化活性。此外，还介绍了在NiO-TiO ₂ / UV工艺下气相光催化CO ₂还原的示意图。