Sofia Stefa

• Physicist, M.Sc., PhD
• Technical University of Crete

The rational design and development of highly-active photocatalytic materials for the degradation of dangerous chemical compounds, such as parabens, is one of the main research pillars in the field of photocatalysis. Graphitic carbon nitride (g-C3N4) is a 2D non-metal material and is considered one of the most promising photocatalysts, because of i...

Heterogeneous photocatalysis is a promising technology for the degradation of environmental pollutants. In this work, g-C3N4 nanosheets were employed as a visible light photocatalyst to investigate the stability, kinetics and to understand the impact of humidity on the photocatalytic oxidation of nitric oxide (NO). Graphitic carbon nitride (g-C3N4)...

Ceria-based mixed oxides have been widely studied in catalysis due to their unique surface and redox properties, with implications in numerous energy- and environmental-related applications. In this regard, the rational design of ceria-based composites by means of advanced synthetic routes has gained particular attention. In the present work, ceria...

The rational design of highly efficient, noble metal-free metal oxides is one of the main research priorities in the area of catalysis. To this end, the fine tuning of ceria-based mixed oxides by means of aliovalent metal doping has currently received particular attention due to the peculiar metal-ceria synergistic interactions. Herein, we report o...

Herein, motivated by the excellent redox properties of rod-shaped ceria (CeO2-NR), a series of TM/CeO2 catalysts, employing the first-row 3d transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) as active metal phases, were comparatively assessed under identical synthesis and reaction conditions to decipher the role of active metal in the CO2 h...

In the present work, the individual or synergistic effect of Ni-based catalysts (Ni/CeO2, Ni/Al2O3) and an eutectic carbonate salt mixture (MS) on the CO2 gasification performance of olive kernels was investigated. It was found that the Ni/CeO2 catalyst presented a relatively superior instant gasification reaction rate (Rco) compared to Ni/Al2O3, i...

This paper reports the fabrication of multifunctional composite cryogels that simultaneously remove oil and dye from polluted water through gravity-driven filtration. The cryogels were prepared via cryopolymerization of a poly(sodium acrylate) (PSA) and graphitic carbon nitride nanosheets (CNNs) mixture. Although the different CNNs concentrations t...

The production of either CO or CH4 via the hydrogenation of CO2 is amongst the most promising routes for CO2 utilization. However, kinetic barriers necessitate the use of a catalyst, with Ni/CeO2 being one of the most investigated systems. Nevertheless, surface chemistry fine-tuning via appropriate promotional routes can induce significant modifica...

The copper–ceria (CuOx/CeO2) system has been extensively investigated in several catalytic processes, given its distinctive properties and considerable low cost compared to noble metal-based catalysts. The fine-tuning of key parameters, e.g., the particle size and shape of individual counterparts, can significantly affect the physicochemical proper...

The structure sensitivity of CO2 methanation was explored over nickel particles (10–25 nm) supported on CeO2 nanorods. An optimum Ni particle size of 20 nm was revealed, with the corresponding sample demonstrating remarkable activity, i.e., 187 μmol CH4 g⁻¹ s⁻¹ and 92 % CH4 yield at 275 °C, which is among the highest ever reported. Notably, the int...

Herein, novel Cu2O-CuO/HTC composites were prepared by hydrothermal precipitation employing as carrier sawdust hydrochar carbonized at 200 C for 2, 6, and 12 h. The composites were used for the effective sonocatalytic degradation of three dyes (Acid Blue 92 (AB 92), Acid Red 14 (AR 14) and Acid Orange 7 (AO 7)) with different molecular structure. T...

Nickel particles deposited on hydrothermally synthesized ceria nanorods (CeO2-NR) were found to be highly active and stable for CO2 methanation. A CO2-to-CH4 yield of 92% was achieved at 300 °C. The superior performance of Ni/CeO2-NR was demonstrated through a comparison with i) CeO2 and Ni/CeO2 commercial products, ii) various M/CeO2-NR lab-synthe...

In this work we report on the combined impact of active phase nature (M: Co or Cu) and ceria nanoparticles support morphology (nanorods (NR) or nanocubes (NC)) on the physicochemical characteristics and CO 2 hydrogenation performance of M/CeO 2 composites at atmospheric pressure. It was found that CO 2 conversion followed the order: Co/CeO 2 > Cu/C...

Ceria has been widely studied either as catalyst itself or support of various active phases in many catalytic reactions, due to its unique redox and surface properties in conjunction to its lower cost, compared to noble metal-based catalytic systems. The rational design of catalytic materials, through appropriate tailoring of the particles’ shape a...