Controllable Synthesis And Properties Exploration Of In₂S₃ Micro/Nanocrystallites And Their Composites

The semiconductor photocatalytic is considered as an effective strategy to solve the energy issue and water pollution.β-In2S3 is a photocatalyst with narrow band gap in defective spinel structure,and it has been widely used in the photocatalystis field due to respond to visible light.In this work,pure-phase In2S3 photocatalyst was synthesized via the hydrothermal by changing the reaction conditions.On this basis,RGO@In2S3 composites photocatalyst,Ag/In2S3 photocatalyst and RGO/Ag/In2S3 photocatalyst were successfully prepared,which inhibited the recombination of photogenerated carriers and enhanced the utilization of sunlight by photocatalyst materials.And the conclusions are shown follows:(1)In2S3 photocatalyst was synthesized by changing hydrothermal conditions(temperature,ratio of water to ethanol).The morphology,microstructure,optoelectronic properties and photocatalytic properties of as-prepared RGO@In2S3 photocatalysts were studied at difference conditions.The results show that excellent crystallinity of In2S3 were prepared at reaction temperature of 180℃,the reaction solvent of water by hydrothermal reaction for 12 h,which could enhance the separation and transmission efficiency of photo-generated carriers.(2)A novel photocatalytic RGO@In2S3 was synthesized via hydrothermal method.The morphology,microstructure,optoelectronic properties and photocatalytic properties of as-prepared RGO@In2S3 photocatalysts were studied by adjusting the amount of GO.The results shown that photogenerated electron can be transfered from the In2S3 surface to surface RGO,which effectively inhibited the recombination of photogenerated carriers due to the difference in Fermi energy levels between RGO and In2S3.When GO was added at 2 mg,the synthesized RGO@In2S3 showed the best photocatalytic performance.Under visible light irradiation for 150 min,the degradation efficiency of MO was 99%.In addition,the active species tests demonstrated that the superoxide radical(1O2-)and h+were responsible for the efficient degradation of MO over Ag/In2S3.(3)A highly photocatalytic Ag/In2S3 was prepared via a UV light photoreduction method.It was found that when Ag NPs were anchored on the surface of In2S3,and then the Schottky junction formed between Ag and In2S3.Schottky junction could effectively inhibited the recombination of photo-generated carriers.In addition,photocatalyst enhances absorption of visible light due to SPR of Ag.A2-IS showed the enhanced photocatalytic efficiency of 97%under visible light irradiation for 90 min,which was about 3.0 times higher than that of the pure In2S3.The cyclic stability test indicated that the A2-IS had excellent cycle performance after 5 cycles.(4)The Ag@RGO/In2S3 photocatalyst was successfully prepared by hydrothermal and UV light reduction methods.We investigated the effects of Ag and RGO on the performance of In2S3 photocatalysts.The result shown that recombination of photo-generated carriers was suppressed due to built-in electric field inside Ag@RGO/In2S3 ternary photocatalyst.In addition,RGO enhanced absorption of NIR light due to SPR effect of Ag,which improved the Ag@RGO/In2S3 photocatalytic activity.The Ag@RGO/In2S3 composites showed the enhanced photocatalytic efficiency of 95%under NIR light irradiation for 210 min.