Modulating Tit_2gOrbital Occupancy in a Cu/TiO₂Composite for Selective Photocatalytic CO₂Reduction to CO

Abstract

The electronic structure of composites plays a critical role in photocatalytic conversion, whereas it is challenging to modulate the orbital for an efficient catalyst. Herein, we regulated the t 2g orbital occupancy state of Ti to realize efficient CO 2 conversion by adjusting the amount of photo-deposited Cu in the Cu/ TiO 2 composite. For the optimal sample, considerable electrons transfer from the Cu d orbital to the Ti t 2g orbital, as proven by X-ray absorption spectroscopy. The Raman spectra results also corroborate the electron enrichment on the Ti t 2g orbital. Further theoretical calculations suggested that the orbital energy of the Ti 3d orbital in TiO 2 is declined, contributing to accepting Cu 3d electrons. As a result, the Cu/TiO 2 composite exhibited an extremely high selectivity of 95.9 % for CO, and the productivity was 15.27 μmol g À 1 h À 1 , which is almost 6 times that of the original TiO 2 . Our work provides a strategy for designing efficient photocatalysis as a function of orbital regulation.

Intercalant-induced V t 2 g orbital occupation in vanadium oxide cathode toward fast-charging aqueous zinc-ion batteries

“…In NH 4 + -V 2 O 5 , width and resonance of this peak become broadened and reduced, respectively, compared with commercial V 2 O 5 , revealing the electronic transitions to 3 d xy state, thus the lowest conduction band is occupied ( 25 ). The decrease in the intensity of V L 3 -edge and L 2 -edge corresponds to electronic occupation of V t 2 g and the reduction of V 5+ , which benefits the electron transfer ( 26 ). In the O K-edge, peaks between 525 and 535 eV arise from the transition of O 1 s electrons to V 3 d -O 2 p ( t 2 g ) and V 3 d -O 2 p ( e g ) states, respectively, corresponding to π and σ interaction ( 27 ).…”