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

Abstract

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 O2 via the B–N polar bond, leading to the implementation of HCHO chemisorption and O2 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.