Citric acid-assisted in-situ synthesis of a distinctive 3D flower-like spherical Bi2MoO6 nano-film and its enhanced CO2 photoreduction activity

Abstract

The photocatalytic CO2 reduction reaction for producing chemical fuels is an ideal advanced technology to effectively mitigate global warming and the energy crisis. Importantly, how to achieve excellent activity and cyclic utilization of photocatalysts has been one research hot-topic. In this work, a Bi2MoO6 (BMO) nano-film with a 3D flower-like spherical structure was fabricated on a Bi plate via a room-temperature in-situ electrochemical ion-exchange method with the assistance of citric acid (CA) (BMO (+CA)). The experimental results show that the BiOBr nano-film, as sacrificial template, plays an important role in the synthesis of the BMO nano-film. The BMO (+CA) nano-film exhibits superior photocatalytic CO2 reduction activity with a CO yield (258μmol g−1), under simulated sunlight irradiation, 3.6 times higher than the BMO (-CA) nano-film with a nanosheet-like structure. Moreover, the dominating reason and action mechanism of the enhanced photocatalytic CO2 reduction performance for the BMO (+CA) nano-film are proposed. Our outcomes provide new insights into the development and research of highly-efficient Bi-based nano-films in the CO2 reduction reaction field.