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Bacterial and organic pollutants are major problems with potential adverse impacts on human health and the environment. A promising strategy to alleviate these impacts consists in designing innovative photocatalysts with a wider spectrum of application. In this paper, we report the improved photocatalytic and antibacterial activities of chemically precipitated Ag 3 PO 4 microcrystals by the incorporation of W at doping levels 0.5, 1, and 2 mol %. The presence of W directly influences the crystallization of Ag 3 PO 4 , affecting the morphology, particle size, and surface area of the microcrystals. Also, the characterization via experimental and theoretical approaches evidenced a high density of disordered [AgO 4 ], [PO 4 ], and [WO 4 ] structural clusters due to the substitution of P 5+ by W 6+ into the Ag 3 PO 4 lattice. This leads to new defect-related energy states, which decreases the band gap energy of the materials (from 2.27 to 2.04 eV) and delays the recombination of e′–h • pairs, leading to an enhanced degradation process. As a result of such behaviors, W-doped Ag 3 PO 4 (Ag 3 PO 4 :W) is a better visible-light photocatalyst than Ag 3 PO 4 , demonstrated here by the photodegradation of potential environmental pollutants. The degradation of rhodamine B dye was 100% in 4 min for Ag 3 PO 4 :W 1%, and for Ag 3 PO 4 , the obtained result was 90% of degradation in 15 min of reaction. Ag 3 PO 4 :W 1% allowed the total degradation of cephalexin antibiotic in only 4 min, whereas pure Ag 3 PO 4 took 20 min to achieve the same result. For the degradation of imidacloprid insecticide, Ag 3 PO 4 :W 1% allowed 90% of degradation, whereas Ag 3 PO 4 allowed 40%, both in 20 min of reaction. Moreover, the presence of W-dopant results in a 16-fold improvement of bactericidal performance against methicillin-resistant Staphylococcus aureus . The outstanding results using the Ag 3 PO 4 :W material demonstrated its potential multifunctionality for the control of organic pollutants and bacteria in environmental applications.

The challenge of providing good quality reclaimed water free from contaminants of emerging concern, even at small concentrations, i.e., microcontaminants (MCs) and pathogens are main hot topics worldwide.

Four different treatment methods based on the HO% production were assessed to oxidize and mineralize the herbicide picloram (PCL), which is considered very toxic and so is a potential contaminant of surface and ground water. The processes based on the Fenton type (homolysis reaction of HOCl by Fe 2+ ions) and photo-Fenton type reaction (using a 9 W UVA light) with in situ electrogenerated HOCl species, using a commercial DSA ® anode in the presence of Cl − ions, led to poor mineralization performances in comparison to the HOCl/UVC process. In that case, the homolysis reaction of HOCl mediated by a 5 or 9 W UVC light resulted in almost complete removal of the organic load within 12 h of treatment, from acidic to neutral solutions and using 1 g L −1 of NaCl concentration after optimization of the experimental conditions. When the HOCl/UVC process using a 5 W UVC light is compared to the electrochemical method using a boron-doped diamond anode (electrochemical/BDD), the oxidation and mineralization rates of the HOCl/UVC process were always superior, with ∼95% removal of total organic carbon (TOC) after 12 h treatment. The energy consumption per unit mass of removed TOC remained around 4 and 8 kW h g −1 for the HOCl/UVC and electrochemical/BDD treatment processes after 90% removal of TOC, respectively, even considering the energy consumption of the UVC lamp. In the final treatment stages, high CO 2 conversions were obtained using both methods, as the generated intermediates were almost completely eliminated. Finally, the HOCl/UVC process is a reasonable option to treat solutions contaminated with organic pollutants as the common problems associated with the Fenton based (acidic solution, Fe 2+ ion recovery, generation of H 2 O 2) and electrochemical/BDD (mass transport) processes can be readily circumvented.