New material shows promise for cleaning polluted water using sunlight
Scientists have engineered a calcium phosphate compound doped with zinc that can break down industrial dyes when exposed to light, offering a potential low-cost approach to water treatment. The findings could interest wastewater treatment operators and companies developing sustainable pollution control technologies.
Originaltitel: The impact of Zn<sup>2+</sup> doping in modifying the surface, structural, and photocatalytic properties of β-Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub>
<p>In this study, the impact of Zn2+ doping on β-Ca3(PO4)2 characteristics was investigated with particular focus on its influence on the surface, structure, and photocatalytic properties. Zn2+ doped β-Ca3(PO4)2 (Znx-TCPs) were synthesized using a solid-state method and were thoroughly studied to evaluate the modification induced by cationic substitution. The structural analysis revealed a noticeable shrinkage in the lattice parameters a and c and the unit cell volume induced by Zn2+ doping. Minor spectral changes in the vibrational modes of PO43− were also observed in the infrared and Raman spectra of Znx-TCPs. The influence of doping on the materials’ morphology was insignificant; however, molten grain boundaries were noticeable at high Zn concentration, x ≥ 1. X-ray photoelectron spectroscopy (XPS) revealed that the surface of the doped materials was rich in Zn. Optical absorption measurements indicated that Zn2+ doping slightly affects the optical bandgap of β-Ca3(PO4)2. The photocatalytic activities of the materials were investigated for the degradation of Rhodamine B (RB) and Methylene blue (MB). The photocatalytic experiments were carried out in the presence of hydrogen peroxide and under simulated solar light. The samples exhibited enhanced catalytic activity compared to β-Ca3(PO4)2, and the Zn0.5-TCP sample demonstrated the highest degradation efficiency. This sample showed excellent stability during the reusability tests, which suggests the suitability of Zn0.5-TCP for use as an efficient photocatalyst. Surface defects are believed to play an important role in the production of active species during the photocatalytic reaction.</p>