Constructing a novel NaLa(WO4)2/g-C3N4 Z-scheme heterojunction with efficient carrier separation for excellent photocatalytic purification of NO

Abstract

In this paper, a novel NaLa(WO4)2/g-C3N4 photocatalyst with Z-scheme heterojunction was synthesized for the first time, and the photocatalytic purification of NOx was used as an evaluation method of its activity. The structure was analyzed in depth by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and other characterization methods. NaLa(WO4)2 and g-C3N4 have obvious interfaces and successfully constructed a Z-scheme heterojunction structure. The combination of photogenerated electrons on the conduction band (CB) of NaLa(WO4)2 with holes on the valence band (VB) of g-C3N4 leads to the accumulation of the remaining holes and electrons on the VB of NaLa(WO4)2 and CB of g-C3N4, and finally realizes the effective separation of photogenerated carriers and maintains the high redox ability of the catalyst. The NaLa(WO4)2/g-C3N4 composite catalyst has a highest NO purification rate of 47.18%, which is 16.51% higher than pure g-C3N4. Moreover, the In-situ DRIFTS monitors the reaction intermediates and final products of NO on the NaLa(WO4)2/g-C3N4 heterojunction surface under visible light irradiation, and provides the corresponding reaction equations. This work provides a new type of photocatalyst that is easy to prepare and highly active, as well as a low-cost photocatalytic treatment technology to remove NO in the environment.