Rational Design of W-Doped Ag₃PO₄ as an Efficient Antibacterial Agent and Photocatalyst for Organic Pollutant Degradation

Abstract

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.

Effect of calcination temperature and pressure-assisted heat treatment on the dye degradation performance of SnO2 photocatalyst obtained by a simple synthesis method

“…6b and d show the plots of ln(C/C 0 ) vs. irradiation time. The reaction rate constants, k, are calculated by the kinetics Equation [44]: where k is the apparent pseudo-first-order rate constant, C 0 is the RhB concentration at the initial time, C is the dye concentration and t is the reaction time (min).…”

Solvent Effect on the Structural, Optical, Morphology, and Antimicrobial Activity of Silver Phosphate Microcrystals by Conventional Hydrothermal Method

“…The structural arrangement of silver phosphate, as well as its optical properties, allow the strong absorption of visible light, mainly due to the small bandgap value, close to 2.4 eV, associated with the electronic transitions between Ag (4d) and O(2p) orbitals, present in the valence band (VB) to Ag (5s and 5p) and P (3s) orbitals arranged in the conduction band (CB) thus, giving it the intense yellow color, characteristic of this material. 42 Several methodologies have been used to obtain silver phosphate with size and morphologies by the literature, 28 resulting in materials with distinct optical, structural, morphological, and semiconductor properties. Among the synthesis methods commonly employed, it is possible to highlight the chemical methods in an aqueous medium based on different precursors of silver ions and phosphorus ions.…”

Ag3PO4Nanoparticles-Decorated Melamine–Formaldehyde Polymer Nanocomposite as a Catalyst for the Photodegradation of Bisphenol A and its Antibacterial Activity

“…Wang et al utilized graphene oxide­(GO)/Ag 3 PO 4 , Mu et al used Ag 3 PO 4 –graphene hydrogel, and Bhunia et al used an r-GO composite fabricated with silver nanoparticles under visible light irradiation, for BPA degradation . The advantage associated with using Ag in organic and inorganic compounds is their well-known antibacterial properties, along with their favorable photocatalytic activities . However, smaller Ag nanoparticles are more prone to aggregation and can cause potential toxicity to human cells, so they are generally incorporated into different nanomaterials as a template, such as GO, carbon nanotubes, and silica nanoparticles. , Wen et al used 1–6 mg/mL MF/[Ag­(NH 3 ) 2 ] + composite microspheres for antibacterial application.…”