Enhanced photoelectric performance of GQDs anchored WO3 with a ‘dot-on-nanoparticle’ structure

Abstract

Abstract WO3/GQDs-H composites were synthesized by a hydrothermal method using WCl6 as the tungsten source. Various analyses were conducted to investigate the composition, structure, morphology and performance of the composites. WO3/GQDs-H composites formed a special ‘dot-on-nanoparticle’ structure by anchoring GQDs on the surface of WO3. The lattice spacings of 0.34 and 0.386 nm were attributed to the (002) facets of GQDs and WO3, respectively. Compared to blank WO3, an obvious shift to higher value in the binding energy of W6+ and W5+ and a decreased ID/IG value in the Raman spectra could be observed for WO3/GQDs-H composites. The photocurrent value of hydrothermal synthesized WO3/GQDs-H composites achieved 1.56 × 10–5 A cm−2, which was obviously prior to that of blank WO3 and mechanically mixed WO3/GQDs. The result indicated that the hydrothermal process promoted GQDs as a conductive route to transfer photoexcited electrons and improve the photoelectric performance of WO3/GQDs in comparison to the mechanical mixture process.