CO₂ photoreduction with water to obtain solar fuels is one of the most innovative and sustainable processes to harvest light energy and convert it into hydrocarbons. Although photocatalytically active materials and photoreactors have been developed for this purpose, lack of standardisation in testing conditions makes the assessment of process parameters and the comparison of material performance a challenge. Therefore, this paper is aimed at investigating the effect of CO₂ photoreduction parameters irradiance and reaction time on production of methane from two photocatalytic rigs. This was pursued through a design of experiments (DOE) approach, which assessed the influence of experimental conditions between different setups. Using low irradiance (40–60 W m⁻²), reaction time and temperature significantly affected methane production, with a maximum production of 28.50 μmol g_cat⁻¹ (40 W m⁻², 4 h). When using high irradiance (60–2400 W m⁻²), only irradiance was found to significantly affect methane production, with a maximum production of 1.90 ∙ 10⁻¹ μmol g_cat⁻¹ (1240 W m⁻², 2 h). Considering proposed reaction mechanism for CO₂ photoreduction, this paper highlights that experimental results give different yet complementary information on the two most important steps of the process, i.e. photoexcitation and surface chemical reaction.

用水对CO _2进行光还原以获取太阳能是收集光能并将其转化为碳氢化合物的最具创新性和可持续性的过程之一。尽管已经为此目的开发了光催化活性材料和光反应器，但是测试条件的缺乏标准化使得评估工艺参数和比较材料性能成为一个挑战。因此，本文旨在研究CO _2光还原参数辐照度和反应时间对两种光催化装置生产甲烷的影响。这是通过实验设计（DOE）方法来实现的，该方法评估了不同设置之间实验条件的影响。使用低辐照度（40–60 W m ^-2），反应时间和温度显着影响甲烷的产生，最大产生量为28.50μmolg _cat ^-1（40 W m ^-2，4 h）。当使用高辐照度（60-2400脉冲W M ^-2）中，仅辐照被发现显著影响甲烷生产，具有最高产量1.90∙10 ^-1微摩尔克_猫^-1（1240脉冲W M ^-2，2小时）。考虑到提出的CO _2光还原反应机理，本文强调实验结果给出了有关该过程中两个最重要步骤即光激发和表面化学反应的不同但互补的信息。