| As industrialization progresses,environmental pollution has caused irreversible damage to the ecosystem.Photocatalysis,which conforms to the concept of green and sustainable development and has a high redox capacity,has shown great potential in environment.But exploring stable and efficient photocatalysts remains an essential task.Titanium carbide（Ti3C2）and molybdenum disulfide（Mo S2）,in contact with semiconductors can form Schottky junctions,enhancing the separation of photo-generated carriers significantly and demonstrating enormous possibilities in photocatalysis.In this work,g-C3N4/TiO2@Mo S2 and g-C3N4/TiO2/Ti3C2 photocatalysts are prepared,and the two photocatalysts have been characterized and tested for their photocatalytic performance,respectively.The ternary double Z-scheme g-C3N4/TiO2@Mo S2 heterojunction photocatalysts have been fabricated with Mo S2 as the carrier,and titanium dioxide（TiO2）nanoparticles uniformly wrapped on the surface of Mo S2,through calcination of composite graphite-phase carbon nitride（g-C3N4）nanosheets.Under illumination,the Z-scheme heterojunction formed on the surfaces of g-C3N4,Mo S2 and TiO2 dramatically enhances the photocatalytic performance of g-C3N4/TiO2@Mo S2.Meanwhile,the tight connection among g-C3N4,Mo S2 and TiO2 creates a unique charge transfer/separation path that facilitates the transfer/separation of electron-hole pairs.1 g g-C3N4 is calcined and composite with various additions of TiO2@Mo S2（20 mg,60 mg,100 mg）,respectively.When the addition amount of TiO2@Mo S2 is 60 mg and calcined at 420℃for 3 h,g-C3N4/TiO2@Mo S2 has the best photocatalytic performance,and the degradation efficiency of methyl orange（MO）can reach 89.52%,which is approximately 1.73 times that of g-C3N4 and 14.98times that of Mo S2,respectively.Then,ternary Z-scheme heterojunction g-C3N4/TiO2/Ti3C2 photocatalysts are designed and fabricated.The Z-scheme heterojunctions formed on the surfaces of g-C3N4 and TiO2 dramatically modify the photocatalytic performances of the compound under illumination.Meanwhile,in this process,multilayer Ti3C2,as the transport medium of Z-scheme heterojunction,is tightly bonded to TiO2 generated by hydrothermal oxidation and g-C3N4 with large specific surface area,which effectively facilitates the space charge separation and depresses the charge recombination.1 g g-C3N4 is calcined and compounded with different additions of TiO2/Ti3C2（40 mg,60 mg,80 mg,100mg）,respectively.When the addition amount of TiO2/Ti3C2 is 80 mg and calcined at 450℃for 4 h,g-C3N4/TiO2/Ti3C2 has the greatest photocatalytic performance,and the kinetic constant for degradation MO was about 3.62 times that of g-C3N4 and 14.55 times that of Ti3C2,respectively.This work illustrates that g-C3N4/TiO2@Mo S2 and g-C3N4/TiO2/Ti3C2have outstanding potential and offers novel insights for designing and synthesizing new ternary heterojunction materials. |
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