Strong Electronic Interaction Enables Enhanced Solar-Driven CO₂ Reduction into Selective CH₄ on SrTiO₃ with...

Targeting selective CO₂ photoreduction into CH₄ remains a challenge due to the sluggish reaction kinetics and poor hydrogenation ability of the unstable intermediate. Here, the active Pt²⁺ sites were photodeposited on the SrTiO₃ photocatalyst, which was well demonstrated to manipulate the CH₄ product selectivity. The results showed that SrTiO₃ mainly yielded the CO (6.98 μmol g^-1) product with poor CH₄ (0.17 μmol g^-1). With the Pt²⁺ modification, 100% CH₄ selectivity could be obtained with an optimized yield rate of 8.07 μmol g^-1. The prominent enhancement resulted from the following roles: (1) the strong electronic interaction between the Pt²⁺ cocatalyst and SrTiO₃ could prompt efficient separation of the photoelectron-hole pairs. (2) The Pt²⁺ sites were active to capture and activate inert CO₂ into HCO^3- and CO₃^2- species and allowed fast *COOH formation with the lowered reaction barrier. (3) Compared with SrTiO₃, the formed *CO species could be captured tightly on the Pt²⁺ cocatalyst surface for generating the *CH₂ intermediate by the following electron-proton coupling reaction, thus leading to the CH₄ product with 100% selectivity.