Photo-induced surface oxygen vacancy in hierarchical nanoarchitectonics g-C3N4/BiOCOOH to boost photocatalytic CO2 reduction

Photocatalytic CO2 conversion into chemical production and valuable solar fuel has been regarded as a prospective strategy for tackling with the issue of the global warming and energy crisis. A superior photocatalytic system employing heterojunction or oxygen vacancy (OVs) can facilitate efficient charge separation and transfer carriers. In this work, well-designed g-C3N4/BiOCOOH heterojunction microflowers assembly incorporated with abundant oxygen vacancy have been successfully synthesized via a mild photo irradiation treatment method. The BiOCOOH coupled with different amounts of g-C3N4 has an obviously impact on photocatalytic CO2 reduction into CO and CH4. Intriguingly, the as-obtained photo-induced oxygen vacancy g-C3N4/BiOCOOH-10 (CNB-10) show further enhanced CO yield towards photocatalytic CO2 reduction compared with pristine g-C3N4/BiOCOOH. Based on comprehensive characterization, the photo induced plenty of OVs in g-C3N4/BiOCOOH via UV light irradiation for 10 min could promote CO2 adsorption capacity as well as separation and transfer of photo-induced carriers, and significantly boost catalytic activity toward CO2 photoreduction. The elevated CO2 photoreduction activity of CNB-10 could be ascribed to the synergic effect of oxygen vacancy and S-scheme heterojunction structure on efficient carrier utilization and visible light absorption. This work can offer new perspectives and guidelines for the rational design of catalysts with satisfactory performance of CO2 reduction.