In situ synthesis of mesoporous TiO2 doped with bismuth single atoms for tunable photocatalytic degradation of formaldehyde

Abstract

Modification of a photocatalyst with single-atom metals to maximize atomic utilization and suppress charge carrier recombination is an effective strategy to dramatically improve the photocatalytic performance. Here we report the first successful development of the mesoporous TiO2 doped with Bi single-atom catalyst. The resulting single-atom photocatalyst possesses a narrower band gap structure, enhanced conductivity and outstanding photocatalytic activity driven by full spectrum light, which is 20 times higher than that of the commercial TiO2. As evidenced by photo-electrochemical characterizations and density functional theory (DFT) calculations, the Bi single atoms are confirmed to exhibit strong capacity to trap photo-generated electrons and probably act as the active sites in photocatalytic formaldehyde (CH2O) degradation. Additionally, reactive oxygen species (O2−, OH, and 1O2) were identified as key ingredients in promoting CH2O decomposition to CO2 and H2O. This innovative approach provides a promising method for fabricating mesoporous single-atom catalysts with tunable catalytic property.