Hydrothermal Synthesis of Li9Fe3(P2O7)3(PO4)2 Nanoparticles and Their Photocatalytic Properties under Visible-Light Illumination

Abstract

A visible-light-driven photocatalyst, Li9Fe3(P2O7)(3)(PO4)(2), prepared by a hydrothermal method was studied. The as-prepared catalyst exhibited efficient photocatalytic activity in the degradation of methylene blue (MB) under visible-light irradiation (lambda > 400 nm). Besides decoloring, the decomposition of phenol was also observed, further demonstrating the photocatalytic performance of Li9Fe3(P2O7)(3)(PO4)(2). It was found that hexadecyltrimethylammonium bromide (CTAB) affected the geometry, crystallinity, optical property, surface area, and photocatalytic activity of the material significantly. The sample obtained with CTAB addition during synthesis procedure showed the higher photocatalytic activity. 70% of MB could be photodegraded under visible-light irradiation after 3 h, showing the excellent photocatalytic activity of Li9Fe3(P2O7)(3)(PO4)(2). Furthermore, with I- as electron donor, 19 umol/g of hydrogen was photocatalytically evolved from aqueous solutions after 5 h. According to experimental results, a possible photocatalytic mechanism of Li9Fe3(P2O7)(3)(PO4)(2) was proposed.