Abstract: It is significant to develop efficient photocatalysts suitable for rainy days and optimize the carrier dynamics, which is helpful to make use of the near-infrared light that accounts for 50 % of sunlight. However, the controllable design of photocatalysts with high efficiency and stable near-infrared light response is still a challenge. In this work, we creatively prepared the nitrogen-doped carbon (NDC) ultrathin nanosheet, which was further coated on the surface of hollow porous SrTiO₃ (STO), and a three-dimensional porous hollow NDC-STO photocatalyst was achieved with full-spectrum response. The strong penetrating ability of near-infrared light makes it possible to work on rainy days. Moreover, the unique three-dimensional porous hollow structure can promote multiple reflections of sunlight inside the catalyst. Compared with STO, the hybrid has a high CO₂ reduction activity of 134.1 µmol/h/g with the CO selectivity of 91.2 %. The possible photocatalytic paths were analyzed by in-situ infrared and adsorption free energy calculation. The results show that the combination of NDC and STO effectively reduces the energy barrier of *COOH generation, which is the rate-limiting step of CO₂ reduction, thus effectively improving the photocatalytic CO₂ reduction performance and product selectivity. The dynamic behavior of photogenerated carriers was verified by DFT theoretical simulation, surface-transient photovoltage, and transient absorption spectroscopy. This work provides a reference for the design of full-spectrum photocatalysts and the optimization of reaction paths and kinetics.

Key words: Photocatalytic CO₂ reduction, Hollow porous SrTiO₃, Nitrogen-doped carbon materials, Near-infrared light, Carrier dynamics