Microwave-assisted synthesis of CdS intercalated K4Nb6O17 and its photocatalytic activity for hydrogen production

CdS intercalated K4Nb6O17 (designated as K4Nb6O17/CdS) composite photocatalysts were synthesized using a microwave-assisted synthesis. The composite particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray fluorescence spectrometry (XRF), energy dispersive X-ray (EDS), ultraviolet–visible diffuse reflection spectra (UV–vis) and photoluminescence measurements (PL). The photocatalytic properties of these catalysts for hydrogen production were also investigated in the presence of Na2S and Na2SO3 sacrificial reagents. The K4Nb6O17/CdS catalysts synthesized using microwave irradiation were found to possess higher crystallinity than their counterparts, synthesized using conventional methods. The absorption edge of K4Nb6O17 was shifted to the visible light region after the intercalation of CdS. Compared to the conventional synthesis method, the use of microwave irradiation sharply shortened the intercalation time. Furthermore, the K4Nb6O17/CdS sample prepared via microwave irradiation exhibited higher activities for photocatalytic hydrogen production under both UV light and visible light irradiation, and the amounts of hydrogen produced were 265.95 mmol/(g cat) and 5.68 mmol/(g cat) after 3 h of irradiation, respectively. The mechanism of separation of the photogenerated electrons and holes at the K4Nb6O17/CdS composite was discussed.

Graphical abstract.Figure optionsDownload full-size imageDownload high-quality image (65 K)Download as PowerPoint slideHighlights► CdS intercalated K4Nb6O17 was successfully synthesized under microwave irradiation. ► Microwave irradiation sharply shortened the intercalation procedure. ► The photocatalyst exhibited high activity for hydrogen production. ► The mechanism of charge separation in the K4Nb6O17/CdS composites was proposed.