Study on the correlation between pore morphology of porous calcium silicate and high-capacity formaldehyde adsorption

ABSTRACT

A novel porous calcium silicate (PCS) material with unique pore structure prepared from coal fly ash (CFA) was reported. The microstructure was investigated through X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, nuclear magnetic resonance cryoporometry, and Brunauer–Emmett–Teller method. Model describing the nanostructure of the prepared PCS was proposed in this work. Results show that the prepared PCS has open pores, a high specific surface area, and multi-peak pore size distributions (macro-, meso-, and micropores). The unique conical pore structure and interconnected micro-, meso-, and macropores are favourable to the reduction of the diffusion resistance of gas molecules. Benefiting from such a valuable structure, PCS exhibits excellent gas adsorption properties. Used in formaldehyde (HCHO) adsorption experiment, PCS shows excellent properties, including high storage capacity and endurance. The saturated adsorption capacity of the prepared PCS is 2.056 mg/g, which is enhanced by fourfold compared with that of active carbon commercially used for formaldehyde adsorption. This work provides a new, efficient, and rational way to utilize CFA. The prepared material can be used as an efficient and cost-effective adsorbent of HCHO under ambient conditions. Furthermore, the microstructure and the correlation between pore morphology and gas adsorption properties of the prepared PCS are revealed.

GRAPHICAL ABSTRACT

KEYWORDS:

• Coal fly ash utilization
• porous calcium silicate
• formaldehyde adsorption

Acknowledgement

The authors gratefully acknowledge the financial support provided by Natural Science Foundation Project of Inner Mongolia Autonomous Region (grant number2015MS0205), Natural Science Foundation Project of Inner Mongolia Autonomous Region (grant number2016MS0219).

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Junmin Sun http://orcid.org/0000-0002-4176-1979

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by Continuous funding of the Natural Science Foundation Project of Inner Mongolia Autonomous Region (Grant No.2015MS0205), Natural Science Foundation Project of Inner Mongolia Autonomous Region (Grant No.2016MS0219) and Natural Science Foundation Major Project of Inner Mongolia Autonomous Region(Grant No.2018030324).