Nanodisk–like Activated Carbon-Branched Polyamine for Adsorption and Degradation of Gaseous Formaldehyde

Abstract Interactions between surface functional groups of adsorbents and pollutants are key variables controlling adsorption and degradation. Herein, we presented a new approach to address such variables by modifying the surface of activated carbon (AC) with branched polyamine (BPA) to create an efficient hybrid material for tackling a common air pollutant, i.e., formaldehyde (FA). The hybrid AC-BPA possessed amine, –COOH, –OH, and Cl − on its surface, facilitating physical, chemical, and reactive adsorption of FA. Consequently, AC-BPA exhibited a high partition coefficient (PC) of 0.64 mol kg − 1 Pa − 1 (82.3 mg g − 1 adsorption capacity), surpassing pristine AC and associated reported systems. AC-BPA performance was further improved under high relative humidity (e.g., 100% RH), achieving an impressive adsorption capacity of 144.3 mg g − 1 and PC of 1.25 mol kg − 1 Pa − 1 . Further, in-situ diffuse reflectance infrared Fourier-transform spectroscopy revealed that AC-BPA catalyzed the chemical transformation of FA into methylol adducts, H 2 O, and CO 2 . This study opens new approaches to the design of high-performance, energy-efficient, and metal-free hybrid materials for reactive adsorption and effective degradation of FA under ambient conditions.