TiO₂ microsphere with tunable pore and chamber size are prepared by a simple solventhermal method and used as catalyst for the photocatalytic CO₂ reduction. It is found that the hollow microsphere with relative lower surface area of 73.8 m² g⁻¹ exhibits increased pore size of 18.1 nm and cavity structure, leading to higher CO₂ diffusion coefficient of 5.40 × 10⁻⁵ cm² s⁻¹ compared with the solid and yolk/shell microspheres. Therefore, the hollow microsphere possesses more accessible sites for CO₂ adsorption, which finally gives rise to the enhanced CO production rate of 10.9 ± 0.7 μmol g⁻¹ h⁻¹ under simulated sunlight, which is respectively 1.6 and 1.4 times higher than that of solid and yolk/shell microspheres. Electron dynamic study further demonstrates that hollow microsphere shows the highest photocurrent density and the lowest charge recombination among three microspheres structure, which is attributed to the swift CO₂ diffusion providing fresh CO₂ molecules to rapidly scavenge the photo-generated electrons and finally leading to the excellence catalytic reduction performances. This method could be adopted as a general strategy to prepare high performance TiO₂ catalysts with desirable structural qualities for the photocatalytic CO₂ reduction under nature sunlight.

通过简单的溶剂热法制备了孔径和腔室尺寸可调的TiO ₂微球，并将其用作光催化还原CO ₂的催化剂。据发现，用的73.8米相对较低表面积的空心微珠²克^-1表现出增加的18.1 nm和腔体结构的孔径，从而导致更高的CO ₂的5.40×10扩散系数^-5厘米^2个小号^-1相比固体和蛋黄/壳微球。因此，中空微球具有更多的CO ₂吸附位点，最终使CO的产生速率提高了10.9±0.7μmolg ^-1在模拟阳光下的h ^-1分别是固体和蛋黄/壳微球的1.6倍和1.4倍。电子动力学研究进一步表明，中空微球在三个微球结构中显示出最高的光电流密度和最低的电荷复合，这归因于快速的CO ₂扩散，提供了新鲜的CO ₂分子以迅速清除光生电子，并最终导致卓越的催化还原性能。该方法可以作为制备具有理想结构质量的高性能TiO ₂催化剂的一般策略，该催化剂用于在自然光下还原光催化的CO ₂。