Organics degradation is one of the challenges of Advanced Oxidation Processes (AOPs), which are mainly employed for the removal of water and air pollutants [...

Bonelli, B.

Esposito, S.

Freyria, F. S.

Manzoli, M.

English

Institutional Research Information System University of Turin

catalystsEditorialPhotocatalysts for Organics DegradationBarbara Bonelli 1,* , Maela Manzoli 2 , Francesca S. Freyria 1,3 and Serena Esposito 11 Institute of Chemistry, Department of Applied Science and Technology; PoliTO BiomED InterdepartmentalLab, Politecnico di Torino, 10129 Torino, Italy; francesca.freyria@polito.it (F.S.F.);serena_esposito@polito.it (S.E.)2 Department of Drug Science and Technology, Università degli Studi di Torino, Via Pietro Giuria 9,10125 Torino, Italy; maela.manzoli@unito.it3 Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA* Correspondence: barbara.bonelli@polito.itReceived: 11 October 2019; Accepted: 14 October 2019; Published: 21 October 2019Organics degradation is one of the challenges of Advanced Oxidation Processes (AOPs), whichare mainly employed for the removal of water and air pollutants. Compared to stand-alone processes,AOPs are more effective if combined with other removal means, especially to degrade recalcitrant(stable) pollutants in subsequent steps.Integrated systems able to solve the aforementioned issues in a single step could be less expensiveand more efficient, but their development requires advancements from the point of view of bothmaterials and the process. In this Issue, a system consisting of integrated resin adsorption/DielectricBarrier Discharge (DBD) plasma regeneration was proposed to treat some textile dyes, showing thatthe DBD plasma could maintain the efficient adsorption performance of the resin while degrading theadsorbed dye [1].Some AOPs imply the presence of catalyst, especially in photocatalytic processes: the goal ofphotocatalysis is to find efficient and stable materials (under the reaction conditions), which are ableboth to stabilize excitons (i.e., the generated electron/hole pairs) and to exploit solar light. However, thelast two goals remain very ambitious and require breakthrough advances from the point of materialsscience (synthesis methods) and physical chemistry. Moreover, a multi-technique approach could helpin studying the surface and textural properties of the photocatalyst in order to be able to unravel thephenomena regulating excitons formation and stabilization.Different solutions are reported in the literature, including the production of nanocomposites [2,3]and of mixed phases of TiO2 [4]. The former have to be properly designed, like in Z-Schemeg-C3N4/Fe-TiO2 [2] for the photodegradation of phenol, and in heterojunction nanostructuredcomposites for photocatalytic fuel cells [3]: both systems were able to absorb in the Vis region.As a whole, the formation of heterojunctions in the nanocomposites simultaneously favors thephotogenerated electron/hole separation and maintains the reduction and oxidation properties.Occurrence of mixed phases is another means to promote and stabilize excitons, like in DegussaP25, where the mixed rutile/anatase phase is considered responsible for its good photocatalyticperformance. Recently, mixed TiO2 phases containing brookite have been proved to display improvedphotocatalytic efficiency, like in N-doped anatase/brookite nanoparticles [4], obtained with high surfacearea by a low temperature sol-gel technique. Again, the development of new nanomaterials has beenshown to have an impact on the progress of photocatalytic efficiency. Such advancements may beobtained by a plethora of synthesis methods, leading to different nanomaterials, like mixed Ni/Fe-basedMetal Organic Frameworks (MOFs) [5] and Sr aluminates co-doped with Eu and Dy [6]. The former areporous networks, with high specific surface areas, where a thorough physico-chemical characterizationby multiple techniques showed [5] that the occurrence of mixed-metal cluster Fe2NiO was able toenhance the photocatalytic performance further, via an electron transfer effect. The latter materialsCatalysts 2019, 9, 870; doi:10.3390/catal9100870 www.mdpi.com/journal/catalystsCatalysts 2019, 9, 870 2 of 2were instead prepared by different methods, namely with a hydrothermal reaction at low T andusing a sol-gel method [6], pointing out the importance of developing new synthetic routes to obtainengineered (nano)materials for photocatalytic applications.References1. Hao, C.; Xiao, Z.; Xu, D.; Zhang, C.; Qiu, J.; Liu, K. Saturated Resin Ectopic Regeneration by Non-ThermalDielectric Barrier Discharge Plasma. Catalysts 2017, 7, 362. [CrossRef]2. Zhu, Z.; Murugananthan, M.; Gu, J.; Zhang, Y. Fabrication of a Z-Scheme g-C3N4/Fe-TiO2 PhotocatalyticComposite with Enhanced Photocatalytic Activity under Visible Light Irradiation. Catalysts 2018, 8, 112.[CrossRef]3. Pan, H.; Liao, W.; Sun, N.; Murugananthan, M.; Zhang, Y. Highly Efficient and Visible Light ResponsiveHeterojunction Composites as Dual Photoelectrodes for Photocatalytic Fuel Cell. Catalysts 2018, 8, 30. [CrossRef]4. Jiang, L.; Li, Y.; Yang, H.; Yang, Y.; Liu, J.; Yan, Z.; Long, X.; He, J.; Wang, J. Low-Temperature Sol-Gel Synthesisof Nitrogen-Doped Anatase/Brookite Biphasic Nanoparticles with High Surface Area and Visible-LightPerformance. Catalysts 2017, 7, 376. [CrossRef]5. Nguyen, V.H.; Nguyen, T.D.; Bach, L.G.; Hoang, T.; Bui, Q.T.P.; Tran, L.D.; Nguyen, C.V.; Vo, D.N.; Do, S.T.Effective Photocatalytic Activity of Mixed Ni/Fe-Base Metal-Organic Framework under a Compact FluorescentDaylight Lamp. Catalysts 2018, 8, 487. [CrossRef]6. Park, B. Photocatalytic Behavior of Strontium Aluminates Co-Doped with Europium and DysprosiumSynthesized by Hydrothermal Reaction in Degradation of Methylene Blue. Catalysts 2018, 8, 227. [CrossRef]© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open accessarticle distributed under the terms and conditions of the Creative Commons Attribution(CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Photocatalysts for organics degradation

Barbara Bonelli

Multidisciplinary Digital Publishing Institute

Photocatalysts for Organics Degradation

https://iris.unito.it/bitstream/2318/1720353/1/Photocatalysts%20for%20Organics%20Degradation_2019_editorial.pdf

Photocatalysts for organics degradation

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