Strong Electronic Interaction Enables Enhanced Solar-Driven CO 2 Reduction into Selective CH 4 on SrTiO 3 with Photodeposited Pt 2+ Sites.

Targeting selective CO 2 photoreduction into CH 4 remains a challenge due to the sluggish reaction kinetics and poor hydrogenation ability of the unstable intermediate. Here, the active Pt 2+ sites were photodeposited on the SrTiO 3 photocatalyst, which was well demonstrated to manipulate the CH 4 product selectivity. The results showed that SrTiO 3 mainly yielded the CO (6.98 μmol g -1 ) product with poor CH 4 (0.17 μmol g -1 ). With the Pt 2+ modification, 100% CH 4 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 Pt 2+ cocatalyst and SrTiO 3 could prompt efficient separation of the photoelectron-hole pairs. (2) The Pt 2+ sites were active to capture and activate inert CO 2 into HCO 3- and CO 3 2- species and allowed fast *COOH formation with the lowered reaction barrier. (3) Compared with SrTiO 3 , the formed *CO species could be captured tightly on the Pt 2+ cocatalyst surface for generating the *CH 2 intermediate by the following electron-proton coupling reaction, thus leading to the CH 4 product with 100% selectivity.