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

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 AgPO microcrystals by the incorporation of W at doping levels 0.5, 1, and 2 mol %. The presence of W directly influences the crystallization of AgPO, 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], [PO], and [WO] structural clusters due to the substitution of P by W into the AgPO 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 AgPO (AgPO:W) is a better visible-light photocatalyst than AgPO, demonstrated here by the photodegradation of potential environmental pollutants. The degradation of rhodamine B dye was 100% in 4 min for AgPO:W 1%, and for AgPO, the obtained result was 90% of degradation in 15 min of reaction. AgPO:W 1% allowed the total degradation of cephalexin antibiotic in only 4 min, whereas pure AgPO took 20 min to achieve the same result. For the degradation of imidacloprid insecticide, AgPO:W 1% allowed 90% of degradation, whereas AgPO 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 . The outstanding results using the AgPO:W material demonstrated its potential multifunctionality for the control of organic pollutants and bacteria in environmental applications.