Mechanism Of The Synthesis And Enhanced Photocatalytic Performance For 0D/2D Heterojunction Of Vanadate Quantum Dots/Graphitic Carbon Nitride Nanosheets

For the past few decades,increasingly severe environmental pollution and latent energy crisis have drawn increasingly attention to solar energy utilization.Semiconductor photocatalysts are considered to be one of the most promising solution for pollutant elimination and clean energy acquisition.Quantum dots（QDs）/two dimensional（2D）nanosheets 0D-2D nanocomposite is a widely used nanostructure for photocatalyst/photoelectrode.Generally,the interaction between QDs and 2D nanosheets can disperse and stablize the QDs,along with suppressing the recombination of photoexcited charges.Herein,unprecedent heterojunctions of vanadate（AgVO₃,BiVO₄,InVO₄ and CuV₂O₆）QDs/graphitic carbon nitride（g-C₃N₄）NSs exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed.The photoactive contribution,up-conversion absorption and nitrogen coordinating sites of g-C₃N₄ NSs,highly dispersed vanadate nanocrystals,as well as the strong coupling and band alignment between them lead to superior visible-light-driven photoelectrochemical（PEC）and photocatalytic performance,competing with the best reported photocatalysts.For AgVO₃/g-C₃N₄,the photocurrent density of the composites with 30 wt%AgVO₃QDs loading was-1.02 mA/cm².After irradiation for 60 min,54%MO（ka=0.0141）is degraded over 30 wt%AgVO₃/g-C₃N₄.At the same time,the morphology,chemical structure,synthesis mechanism,photocatalytic performance and mechanism of the novel vanadate quantum dots/g-C₃N₄ nanosheets heterojunctions were systematically investigated.The experimental results show that vanadate quantum dots and g-C₃N₄nanosheets in the heterojunctions show strong interaction with each other,thus promoting the photoinduced electron-hole pair.At the same time,the up-conversion nature of g-C₃N₄ nanosheets can broaden the photoresponsive region of the photocatalyst effectively.This work is expected to provide a new concept to construct multifunctional 0D/2D nanocomposites for a large variety of opto-electronic applications,not limited in photocatalysis.