Hierarchical Pt/NiCo2O4 nanosheets decorated carbon nanofibers for room-temperature catalytic formaldehyde oxidation

Room-temperature catalytic formaldehyde (HCHO) oxidation is regarded as the most promising way for constant and oxidative removal of indoor HCHO. Herein, carbon nanofibers (CNF) with three-dimensional (3D) inter-connection network structure decorated with Pt/NiCo2O4 alloy nanosheets (Pt/NiCo2O4/CNF) were fabricated in-situ to catalyze the oxidation of HCHO at ambient temperature. The presence of CNF helps to inhibit the aggregation of NiCo2O4 nanosheets, expose more active sites and form a hierarchically porous structure, which is conducive to the dispersion of platinum nanoparticles (NPs) and the diffusion of reactants. Besides, oxygen vacancies from Pt-loading process ensure abundant active oxygen species, which are beneficial to HCHO oxidation. Moreover, CNF with microporous structure can strongly adsorb HCHO, rapidly reduce the concen-tration of HCHO in air and increase its concentration near Pt/NiCo2O4, thus accelerating the formaldehyde oxidation reaction. At Pt content as low as 0.5 wt%, Pt/NiCo2O4/CNF exhibits superior HCHO oxidation activity, and conversion of 92.4% can be achieved within 60 min due to the combination of adsorption and oxidation. This work may shed light on fabricating CNF-based 3D catalysts for the practical application of indoor HCHO elimination.