A facile in-situ hydrothermal route to construct a well-aligned beta-Ag2MoO4/g-C3N4 heterojunction with enhanced visible light photodegradation: Mechanistic views

摘要

Constructing a well-aligned heterojunction composite and realizing its photocatalysis mechanism are pivotal in controlling the charge transfer behavior and in turn improving the photocatalytic ability of a photocatalyst. Herein, we report an in situ synthesis of an efficient heterostructured beta-Ag2MoO4/g-C3N4 composite by hydrothermal method. The structural and morphological studies revealed that beta-Ag2MoO4 nanoparticles are uniformly dispersed on the surface of isolated g-C3N4 nanosheets. The photocatalytic abilities and photocatalytic mechanism of beta-Ag2MoO4/g-C3N4 composites were evaluated towards degradation of MO under visible light. The different compositions of beta-Ag2MoO4/g-C3N4 composites were studied for their photocatalytic activities in order to get optimal composition. Photocatalytic efficiency of beta-Ag2MoO4/g-C3N4 composite is much higher than that of the pristine beta-Ag2MoO4 and g-C3N4. Photocatalytic mechanism of heterostructured beta-Ag2MoO4/g-C3N4 composite was discussed in detail with the support of photoluminescence spectra and reactive species trapping experiments. Intimately contacted interfaces with well staggered band alignment of beta-Ag2MoO4/g-C3N4 composite enhance the charge separation and reduction in the probability of electron-hole pair recombination under visible light irradiation and so a significant improvement of the photocatalytic ability. The present work offers to understand the heterojunction mechanism for constructing the efficient composites with remarkable photocatalytic efficiency.