Abstract
Graphene quantum dots (GQDs) as excellent conductive materials could effectively enhance the electron transmission efficiency of W18O49 nanofibers after their combination. In order to investigate the effect of different crystal phase WO3 on the optoelectric properties of GQDs/W18O49 composites, the orthogonal phase WO3 (o-WO3), hexagonal phase WO3 (h-WO3) and tetragonal phase WO3 (t-WO3) had been used to produce GQDs/W18O49/WO3 homojunction with GQDs/W18O49. After comparing them, it was found that the photocurrent intensity of GQDs/W18O49/t-WO3 was 2.35 times, 1.68 times and 1.08 times as high as that of GQDs/W18O49, GQDs/W18O49/o-WO3 and GQDs/W18O49/h-WO3 at 1.2 V versus Hg/Hg2Cl2, respectively. And the t-WO3 could effectively decrease the band gap, reduce the interfacial resistance, prolong the electron lifetime, accelerate the electron conduction and increase the photocurrent magnitude of the homojunction. The photoelectric performance of the composites could be adjusted by regulating the ratios of GQDs/W18O49 and t-WO3, the ratio 2:1 of GQDs/W18O49/t-WO3 composites presented a higher photocurrent density and lower interfacial resistance than other proportions. The physical mechanism of such enhanced photoconduction in this homostructure have been discussed. (C) 2021 Elsevier B.V. All rights reserved.
NSTL
Elsevier