Chemosphere-Inspired Irradiation Reallocation Strategy Based on Mie Theory for Stable CO₂ Photoreduction over Cu₂O

Photocatalytic conversion of CO2 to fuels presents a promising approach to reduce CO2 emissions and address the energy crisis. Cu2O has already emerged as a promising material for carbonaceous generation. However, it suffers from poor photostability caused by the accumulation of photogenerated holes. Here, drawing inspiration from the Earth's chemosphere, we introduce a nanoscale irradiation reallocation strategy employing a TiO2 hollow sphere to shade Cu2O from excess irradiation. Based on Mie theory and near-field electric field distribution, the designed structure can provide a mild illumination environment for Cu2O, thereby mitigating the rapid accumulation of photogenerated holes, thus improving the stability. Additionally, photogenerated electrons from TiO2 can transfer following an all-solid-state Z-scheme mechanism to further neutralize the accumulation holes of Cu2O. Compared to the conventional coverage protection approaches, our strategy not only confirms the shading effect but also ensures the exposure of the Cu2O active sites. Consequently, the catalyst with Cu2O shading by TiO2 hollow sphere exhibits impressive photocatalytic stability and methanol productivity, retaining 76.4% (2593.6 μmol g–1 h–1) after the fourth cycle.