An effective strategy to improve the photothermocatalytic activity of Co3O4 for VOCs degradation: Specifically enhancing the surface lattice oxygen activity.

[Display omitted] • Activation of surface lattice oxygen could be achieved by structure optimization. • More active surface lattice oxygen is exposed on Co 3 O 4 (1 1 2) planes. • Active surface lattice oxygen promotes the ring-open process in toluene oxidation. Co 3 O 4 catalysts with active surface lattice oxygen were constructed via a simple solvothermal method by adopting isopropyl alcohol (IPA) or tert -butyl alcohol (TBA) as solvent. The obtained Co 3 O 4 -IPA and Co 3 O 4 -TBA exhibit flower-like structures with (1 1 2) planes exposed on the surface. Due to abundant unsaturated Co3+ sites existing on the (1 1 2) plane, the content and activity of surface lattice oxygen on Co 3 O 4 -IPA and Co 3 O 4 -TBA are much higher than that on Co 3 O 4 -MA and Co 3 O 4 -EA, which prepared with methyl alcohol or ethyl alcohol as a solvent. The robust surface lattice oxygen on Co 3 O 4 -IPA and Co 3 O 4 -TBA facilitates the ring-opening process during photothermocatalytic oxidation of toluene, significantly promoting the catalytic performance. In the static atmosphere, about 98% of toluene conversion and 80% of CO 2 yield can be achieved on Co 3 O 4 -IPA and Co 3 O 4 -TBA under full-spectrum light irradiation of 325 mW/cm2, much higher than 89% and 73% of conversion, 50% and 26% of CO 2 yield on Co 3 O 4 -EA and Co 3 O 4 -MA, respectively. [ABSTRACT FROM AUTHOR]