Synthesis,Characterization And Activity Assess Of G-C₃N₄ Based Core-shell Structure Composite Photocatalyst

With the challenge of environment pollution and energy crisis,photocatalytic technology is the possible solution.The aim of the research focus on the the novel photocatalyst with high activity.This article is based on the π-π conjugated g-C₃N₄ material with high stablility,combined with the materials like bismuth-based,silver-based photocatalyst,synthesis the new composite photocatalyst,more details are as follows:The g-C₃N₄ nanosheet was obtained by the liquid exfoliated,BiVO₄ and Ag₂Mo₂O₇ were prepared by the hydrothermal method.BiVO₄@g-C₃N₄ and Ag₂Mo₂O₇@g-C₃N₄ core-shell composite photocatalysts were synthesized by chemical adsorption.The new composites were examined with various characterization techniques,the effects of the structure change on the performance of the photocatalyst were investigated.The photocatalytic activity assess was evaluated by degradating the water pollution under visible light.Novel core-shell structured ellipsoid-like BiVO₄@g-C₃N₄ composites,its performance as photocatalyst was systematically evaluated during RhB degradation under visible light irradiation.The composite with 7 wt.% g-C₃N₄ was found to degradate almost 90% RhB in 60 min,which is 7 times more efficient as a photocatalyst than pristine BiVO₄.As for nanorod Ag₂Mo₂O₇@g-C₃N₄,when the amout of g-C₃N₄ nanosheets reached 5 wt.%,Ag₂Mo₂O₇@g-C₃N₄（5 wt.%）showed the highest degradation efficiency,which is 3 times more efficient than pristine BiVO₄.The results of FTIR show core-shell structure modified chemical bands interactions,forming a wider π conjugated system.Their core-shell structure and activity were also found to be highly stable after it was used for 5 times in RhB degradation.The core-shell structure enhanced the contact areas between the BiVO₄ core and g-C₃N₄ nanosheets shell,which provided more active sites and strengthened the chemical band interaction.The thin g-C₃N₄ nanosheets reduced the charge carrier transfer distance,which further suppressed the recombination of the photo-induced electron-hole pairs and therefore the photocatalytic activity of the composites enhanced.A reaction mechanism of the photocatalytic RhB degradation was proposed and discussed in detail.Not only the g-C₃N₄ nanosheets coating improved the photocatalytic activity,but also strengthened the stability.This promising novel core-shell composite photocatalyst provides an exciting area for further study and application.