Unraveling the relationship between exposed surfaces and the photocatalytic activity of Ag3PO4: an in-depth theoretical investigation

Over the years, the possibility of using solar radiation in photocatalysis or photodegradation processes hasattracted remarkable interest from scientists around the world. In such processes, due to its electronicproperties, Ag3PO4is one of the most important semiconductors. This work delves into thephotocatalytic activity, stability, and reactivity of Ag3PO4surfaces by comparing plane waves withprojector augmented wave and localized Gaussian basis set simulations, at the atomic level. The resultsindicate that the (110) surface, in agreement with previous experimental reports, displays the mostsuitable characteristics for photocatalytic activity due to its high reactivity,i.e.the presence of a largeamount of undercoordinated Ag cations and a high value work function. Beyond the innovative results,this work shows a good synergy between both kinds of DFT approaches

A Tale of Reactive Oxygen Species on the Ag3PO4(110) Surface

Herein, we report a study of Ag3PO4 microcrystals in the accomplishment of their enhanced degradation process and bactericidal activity. Based on experimental results and density functional theory free energy profiles, we propose a new mechanism for the multifunctional competence of the Ag3PO4(110) surface. Coadsorbed H2O and O2 molecules regulate an energetically favorable pathway that efficiently activates the dissociation of H2O and stabilizes the formed reactive oxygen species (ROS) precursors: hydroxyl (•OH) and superoxide (•O2–) radicals. This work is a proof of concept to interpret the surface reactions on Ag3PO4 and provides a new perspective to understand at the atomic level the catalytic process/mechanism for the initial stages of ROS production on metal oxide semiconductor surfaces

Bioactive Ag3PO4/Polypropylene Composites for Inactivation of SARS-CoV?2 and Other Important Public Health Pathogens

The current unprecedented coronavirus pandemic (COVID-19) is increasingly demanding advanced materials and new technologies to protect us and inactivate SARS-CoV-2. In this research work, we report the manufacture of Ag3PO4 (AP)/polypropylene (PP) composites using a simple method and also reveal their long-term anti-SARS-CoV-2 activity. This composite shows superior antibacterial (against Staphylococcus aureus and Escherichia coli) and antifungal activity (against Candida albicans), thus having potential for a variety of technological applications. The as-manufactured materials were characterized by XRD, Raman spectroscopy, FTIR spectroscopy, AFM, UV–vis spectroscopy, rheology, SEM, and contact angle to confirm their structural integrity. Based on the results of first-principles calculations at the density functional level, a plausible reaction mechanism for the initial events associated with the generation of both hydroxyl radical •OH and superoxide radical anion •O2– in the most reactive (110) surface of AP was proposed. AP/PP composites proved to be an attractive avenue to provide human beings with a broad spectrum of biocide activity

Make EU trade with Brazil sustainable

Brazil, home to one of the planet's last great forests, is currently in trade negotiations with its second largest trading partner, the European Union (EU). We urge the EU to seize this critical opportunity to ensure that Brazil protects human rights and the environment