Energy processing and fuel combustion processes generate large volumes of CO, NOx, SO2, and volatile organic
compounds (VOCs). These pollutants may pollute the air and water, thus doing harm to humans, animals, plants,
and buildings. Heterogeneous catalysis plays an important role in environmental remediation. Catalytic elimination of environmental
pollutants is more efficient and effective than conventional incineration. In particular, metal oxide catalysts
are cheap, versatile and easy to prepare. Although Co3O4 is not as popular as TiO2 (a photocatalyst) in environmental catalysis,
it shows extraordinary activity in CO oxidation well below room temperature, and therefore has attracted much attention
recently. Here we review the recent progress in the remediation of several environmental pollutants by various
Co3O4 catalysts and furnish our perspectives.