Surface curvature modulation of the boron nitride nanocage to boost formaldehyde adsorption and catalytic oxidation.

• BN nanocages were constructed for synergistically curvature-polarity regulation. • Curved BN nanocages provide chemical anchoring sites for the HCHO molecules. • A multi-channel electron balance transfer mechanism formed in curved BN surface. • Curved BN nanocages present dual-catalytic sites to accelerate HCHO oxidation. Development of efficient catalysts for formaldehyde (HCHO) oxidation is of importance in indoor air pollution treatment. However, the robust design criteria remain greatly challenging because of the poor recognization of structure-function relationships. Herein, by means of density functional theory (DFT) calculations, we proposed a surface modulation strategy to optimize the surface polar bonding state of BN, proving a curvature tuned B–N–B active sites and its relationship with catalytic activity. The results indicated that HCHO can be efficiently adsorbed by the curved BN nanocage with exceptional chemisorption efficiency (up to 97 %) and even under high coverage (two molecules, 86 %). Moreover, the distortion of BN nanocage facilitates the electron transfer from electron-rich O atom of HCHO to B 2p orbital, and then transfer to O 2 via the B–N polar bond, leading to the implementation of HCHO chemisorption and O 2 activation. Thus, a multi-channel for interactive electron transfer was spatially built for the HCHO oxidation on BN nanocage. Finally, a novel BN nanocage initiated advanced HCHO oxidation mechanism, combining the curvature and polarity catalytic effects, is systematically investigated based on reaction-kinetic studies. These findings shed new light on the rational design of HCHO oxidation catalysts and broadened the applications of BN-based materials. In this paper, a strategy of "synergistically curvature and polarity bond regulation" is reported to effectively modulate the electronic structure of BN surface sites to form a multi-channel electron balance transfer mechanism between HCHO/O 2 and catalyst. Benefiting from the curvature-enhanced polarization effect, the curved BN catalyst displays excellent adsorption and catalytic oxidation performance for HCHO. [Display omitted] [ABSTRACT FROM AUTHOR]