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Antibiotics development during the last century permitted unprecedent medical advances. However, it is undeniable that there has been an abuse and misuse of antimicrobials in medicine and cosmetics, food production and food processing, in the last decades. The pay toll for human development and consumism is the emergence of extended antimicrobial resistance and omnipresent contamination of the biosphere. The One Health concept recognizes the interconnection of human, environmental and animal health, being impossible alter one without affecting the others. In this context, antibiotic decontamination from water-sources is of upmost importance, with new and more efficient strategies needed. In this framework, light-driven antibiotic degradation has gained interest in the last few years, strongly relying in semiconductor photocatalysts. To improve the semiconductor properties (i.e., efficiency, recovery, bandgap width, dispersibility, wavelength excitation, etc.), bio-based supporting material as photocatalysts matrices have been thoroughly studied, exploring synergetic effects as operating parameters that could improve the photodegradation of antibiotics. The present work describes some of the most relevant advances of the last 5 years on photodegradation of antibiotics and other antimicrobial molecules. It presents the conjugation of semiconductor photocatalysts to different organic scaffolds (biochar and biopolymers), then to describe hybrid systems based on g-C3N4 and finally addressing the emerging use of organic photocatalysts. These systems were developed for the degradation of several antibiotics and antimicrobials, and tested under different conditions, which are analyzed and thoroughly discussed along the work. [ABSTRACT FROM AUTHOR]

Abstract: The photocatalytic (PC) performance of titanium dioxide (TiO2) nanoparticles strongly depends on their specific surface, the presence of crystal defects, their crystal phase, and the exposed crystal facets. In order to understand which of these factors contributes most significantly to the PC activity of TiO2 colloids, all of them have to be individually analyzed. This study entails the synthesis of five anatase nanocrystal samples. By maintaining the same reactant ratios as well as hydrothermal sol–gel synthesis route and only varying the autoclaving time or temperature, different crystallite sizes are obtained under comparable experimental conditions. A decrease in PC performance with increase in specific surface area is found. Such an unexpected counterintuitive result establishes the basis for a better understanding of the crucial factors that ultimately determine the PC activity. These are investigated by studying nanocrystals bulk and surface structure and morphology using a selection of complementary analysis methods (X‐ray photoelectron spectroscopy (XPS), X‐ray absorption fine structure (XAFS), X‐ray diffraction (XRD)…). It is found that a change in the nanocrystal morphology from an equilibrium state truncated tetragonal bipyramid to a more elongated rod‐like structure accompanied by an increase in oxygen vacancies is responsible for an augmented PC activity of the TiO2 nanocrystals. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we report the successful grafting on silica surfaces by the coadsorption method, of mixed nitrobenzyl ester‐/methyl‐terminated self‐assembled monolayers (SAMs), with ratios of two coupling agents (30/70) and (10/90). We show that the preparation of mixed monolayers using two organosilanes with internal urea groups in the alkyl chain seems to be appropriate to obtain a monolayer composition similar to the molar ratio of the two silanes in the deposition solution. This behavior could be due to the presence of the polar urea groups in the molecular structure of both organosilanes which allows them to have the same ability of self‐assembly by hydrogen‐bonding and also the same affinity with the hydrophilic surface. To locate the ester functions at the surface of the mixed monolayers, we investigated the covalent immobilization of amino functionalized gold nanoparticles (GNPs) as nanoscale marker. Polarization modulation infrared reflection‐adsorption spectroscopy (PM‐IRRAS) and atomic force microscopy (AFM) were used to monitor the chemical modifications of the silica surfaces and to demonstrate the successful attachment of gold nanoparticles onto the modified surfaces. Finally, we show that the mixed SAMs were grafted with a phase separation. [ABSTRACT FROM AUTHOR]

Pre-synthesized mono- and bis(NHC) palladium complexes have been grafted onto magnetic core/shell γ-Fe2O3/silica particles and tested as catalysts in model Suzuki–Miyaura coupling reactions. The bis(NHC) immobilized complex was found to be a robust catalyst that can operate under mild conditions in aqueous media, even for the activation of chloroarene, whereas the mono(NHC) counterpart rapidly deactivates. Moreover, it can be readily recovered by magnetic separation and reused many times, providing very high productivities, and with so low leaching of palladium that the crude products obtained contain ≤10 ppm Pd. [ABSTRACT FROM AUTHOR]

We report the synthesis of a superparamagnetic nanoparticle MNP (γ-Fe2O3/polymer) supported dendritic catalyst based on a bulky electron-rich phosphine Pd(ii) complex. The high reactivity of this catalyst is described in a copper-free Sonogashira C–C cross-coupling reaction in water, and the significant role of surfactant additives is highlighted in the recovery study. [ABSTRACT FROM AUTHOR]