Effect of ion (Ag+, N3−) doping on the photocatalytic activity of the Ruddlesden–Popper-type layered perovskite K2Nd2Ti3O10

Abstract

In recent years, metal–nonmetal codoping has become a promising approach that can be used for effective tailoring of the structure–activity properties of semiconductors in photocatalysis. In the present study, N-doped K 2 Nd 2 Ti 3 O 10 (KNdTON), Ag-doped K 2 Nd 2 Ti 3 O 10 (AgNdTO), as well as N and Ag codoped K 2 Nd 2 Ti 3 O 10 (AgNdTON) photocatalysts were successfully synthesized by solid-state and ion-exchange methods, using the pre-prepared K 2 Nd 2 Ti 3 O 10 (KNdTO). The parent K 2 Nd 2 Ti 3 O 10 catalyst was synthesized using a facile gel-burning method. The prepared materials are characterized by different techniques such as powder X-ray diffraction (XRD), thermogravimetric (TG) analysis, scanning electron microscopy–energy dispersive X-ray (SEM–EDX) spectroscopy, transmission electron microscopy (TEM), high- resolution-TEM (HR–TEM), oxygen–nitrogen–hydrogen (O–N–H) analysis, inductively coupled plasma-optical emission spectroscopy (ICP-OES), Fourier transform-infrared spectroscopy (FT-IR), and diffuse reflectance UV–visible spectroscopy (UV–vis DRS). The photocatalytic activity of the obtained catalysts was investigated by studying the degradation of two different pollutants viz., methylene blue (MB) and methyl violet (MV) under visible light irradiation. The shift in the XRD peaks and absorption edges confirms the incorporation of guest ions into the lattice of KNdTO. The photocatalytic degradation of MB and MV is found to be significantly improved via metal mono-doping and codoping. In particular, AgNdTON showed a remarkable increase in photodegradation compared to KNdTON, AgNdTO, and KNdTO. Such an improved photocatalytic activity of AgNdTON is due to the extended visible light absorption and the lower bandgap energy. Furthermore, AgNdTON demonstrated reasonable photocatalytic activity for the MV degradation up to five cycles.