People in the Spotlight – Dr Julien Mahy

I was born in Liège in Belgium. I studied Chemical Engineering and Material science at the University of Liège (ULiège) and received my diploma in June 2013. Since the beginning of my studies, I was always attracted towards environmental applications and green chemistry. So, I decided to undertake my Master thesis in the Department of Chemical Engineering in the Nanomaterials, Catalysis and Electrochemistry group where several projects addressing environmental issues were developed. My Master thesis, under the supervision of Professor Stéphanie Lambert, was entitled “Remediation of contaminated soil by the coupled action of microorganisms and metallic nanoparticles” and involved the development and characterization of sol-gel catalysts (Fe2 O3 /SiO2 xerogels) for bioremediation applications. The goal was to develop catalysts which can enhance the activity of microorganisms for the degradation of organic pollutants, such as hydrocarbons, present in polluted soils. This work was performed within the framework of the Walloon project NANOMICRO (n# 6917, GREENWIN Pole, Marshall Plan) and received the 2014 Master Thesis Umicore Award.

Afterwards, Professors Stéphanie Lambert and Benoît Heinrichs offered me the opportunity to undertake a co-supervised PhD program (and teaching assistant position) involving the development of sol-gel photocatalysts for removing pollutants from water and air . My thesis focused on the development of a TiO2 aqueous sol-gel process in order to produce, at large scale, hydrophilic photocatalysts with high activity under both visible and UV/visible irradiation, for water and air remediation. The process had to be easily transferrable from lab-scale to pilot scale for industrial applications. Close collaborations with industry partners (Prayon S.A. and CRM Group, Belgium) were maintained throughout the thesis.

In 2018, after a short period working in industry in the CRM group as project leader, I decided to accept a postdoctoral position involving a collaboration between the NCE (ULiège) and the “Institut für Energie- und Umwelttechnik e.V. (IUTA)”, Duisburg (Germany), within the framework of the European AOP-Ti project (22 nd CORNET Call) and in collaboration with the CELABOR Research Center. The AOP-Ti project (Assessment of Advanced Photocatalytic Oxidation process for Micropollutant Elimination in Municipal and Industrial Waste Water Treatment Plants) focusses on the development of a quaternary treatment for water in order to degrade residual organic micropollutants using an ozone oxidation treatment, a subsequent photocatalytic treatment, and finally an adsorption step on bioactivated carbon. We were able to design and construct a pre-industrial-scale reactor which was evaluated on a real waste water treatment plant (WWTP) in Germany, demonstrating the effectiveness of our process for quaternary water treatment.

Since July 2019, I have been a postdoctoral researcher at the Institute of Condensed Matter and Nanosciences (IMCN) at the Université Catholique de Louvain under the supervision of Professor Sophie Hermans. My work involves the development of low-cost sensors for detection of air pollution by producing onion-like composite nanoparticles. These materials swell in contact with pollutants, thus producing a color change. The composite materials are composed of sol-gel metal oxide nanoparticles and polymer. This work is part of an Innoviris project from the Brussels Region in collaboration with Vrije Universiteit Brussels.

Since the beginning of my research activities, I have always focused on the development of sol-gel materials and processes for environmental purposes with a strong emphasis on green synthesis and I hope to continue on this path for many years to come.