Work

Self-wetting triphase photocatalysis for effective and selective removal of hydrophilic volatile organic compounds in air

Year: 2021

Type: article

Abstract: Photocatalytic air purification is widely regarded as a promising technology, but it calls for more efficient photocatalytic materials and systems. Here we report a strategy to introduce an in-situ water (self-wetting) layer on WO 3 by coating hygroscopic periodic acid (PA) to dramatically enhance the photocatalytic removal of hydrophilic volatile organic compounds (VOCs) in air. In ambient air, water vapor is condensed on WO 3 to make a unique tri-phasic (air/water/WO 3 ) system. The in-situ formed water layer selectively concentrates hydrophilic VOCs. PA plays the multiple roles as a water-layer inducer, a surface-complexing ligand enhancing visible light absorption, and a strong electron acceptor. Under visible light, the photogenerated electrons are rapidly scavenged by periodate to produce more •OH. PA/WO 3 exhibits excellent photocatalytic activity for acetaldehyde degradation with an apparent quantum efficiency of 64.3% at 460 nm, which is the highest value ever reported. Other hydrophilic VOCs like formaldehyde that are readily dissolved into the in-situ water layer on WO 3 are also rapidly degraded, whereas hydrophobic VOCs remain intact during photocatalysis due to the “water barrier effect”. PA/WO 3 successfully demonstrated an excellent capacity for degrading hydrophilic VOCs selectively in wide-range concentrations (0.5−700 ppmv).

Source: Nature Communications

DOI: 10.1038/s41467-021-26541-z

Authors: Fei He, Seunghyun Weon, Woojung Jeon, Myoung Won Chung, Wonyong Choi

Institutions: Pohang University of Science and Technology, Korea University

Language: English

Topic: Advanced Photocatalysis Techniques

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: gold

Estimated APC paid: $5,560