Graphene-TiO2 hybrids for photocatalytic aided removal of VOCs and nitrogen oxides from outdoor environment

Autor: José J. Calvino, Nejc Rozman, Vlasta Brezová, Maria Paula Seabra, Dana Dvoranová, David M. Tobaldi, A. Sever Škapin, João A. Labrincha, Bruno R. Figueiredo, Luc Lajaunie
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Chemical Engineering Journal
research@ua; Vol 12 (2021); 31
research@ua; vol. 12 (2021); 31
ISSN: 1385-8947
2182-9357
Popis: Graphical abstract
Highlights • High throughput low-cost sol–gel graphene-TiO2 nanocomposites. • EPR proved different radicals upon excitation: complex reaction pathways. • Stable and high performance photocatalytic removal of VOCs and NOx. • 1 wt% graphene gave 2-fold increase in photocatalytic VOCs & NOx removal. • Graphene to increase electric transport; decrease exciton recombination.
Outdoor and indoor air pollution has become a global concern in modern society. Although many policies and regulations on air quality have been promulgated worldwide over the past decades, airborne pollution still negatively affects health and therefore the life-style of human beings. One of the strategies to challenge this problem might be reducing the amount of airborne pollutant by mineralising them via photoinduced reactions. Photocatalytic oxidation of gaseous pollutants via titanium dioxide is one of the most promising solar photochemical reactions. In this research work, by means of a green sol–gel procedure, we have coupled titania to graphene (0.5 and 1.0 wt%) aiming to increase the solar photocatalytic activity of the produced hybrid materials. Transient paramagnetic species formed upon UV-A irradiation were detected by means of EPR spectroscopy. The photocatalytic reactions were assessed by monitoring the removal of nitrogen oxides and two different volatile organic compounds (benzene and isopropanol), which has never been assessed before. Our results highlight the exceptional characteristics of the TiO2/graphene hybrid material synthesised with 1.0 wt% graphene, and its excellent suitability for multi-purpose applications in the field of environmental remediation. Compared to unmodified titania, it shows a clear enhancement in the photocatalytic removal of those hazardous pollutants, having a photocatalytic degradation rate twice higher. In addition, the same material is highly stable and shows fully recyclability over repeated tests. Hybrid titania-graphene materials could thus be exploited to grant safer outdoor and indoor environments, having thus a beneficial impact on public health and on the quality of our lives.
Databáze: OpenAIRE
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