Fabrication of novel g-C3N4 nanosheet/carbon dots/Ag6Si2O7 nanocomposites with high stability and enhanced visible-light photocatalytic activity

摘要

A series of visible-light-driven g-C3N4 nanosheet/carbon dots/Ag6Si2O7 (signify as GCNNS/CD/ASO) photocatalysts are achieved by a facile precipitation procedure. Among ternary nanocomposites, the GCNNS/CD/ASO (10%) photocatalyst demonstrated the highest performance for degradation of RhB that was nearly 37.4, 10.7, and 4.3 times premier than the bare GCN, GCNNS, and binary GCNNS/CD photocatalysts, respectively. The photocatalytic ability of the GCNNS/CD/ASO (10%) nanocomposite can be assigned to the rapid segregation of generated e(-)/h(+) pairs, because CD act as electron mediator among GCNNS and ASO semiconductors. Furthermore, the h(+), center dot O-2(-), and center dot OH species were obtained as the oxidative species in the photocatalytic system by the scavenging tests. In addition, the degradation intermediates were identified by gas chromatography-mass spectroscopy (GC-MS). Also, through investigating the electrochemical properties, the photocatalytic mechanism based on the energy bands was offered to display the increased e(-)/h(+) pairs separation and migration, which cause the excellent photocatalytic ability. This work highlights the potential application of extremely effective CD and Ag6Si2O7 anchored GCNNS in environmental applications. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.