Preparation And Photocatalytic Properties Of Zn_0.2Cd_0.8S Material And Composites

In recent years,with the consumption of fossil energy crisis and environmental pollution increasing seriously,people are committed to finding new ways to solve these problems,which affect social development in renewable energy.The semiconductor photocatalytic technology has become the research hotspot for research workers,because of its green and efficient features in renewable energy and environmental governance.Due to the adjustment of the band gap and excellent photocatalytic hydrogen evolution reaction performance,Zn_xCd_1-xS solid solution is served as a potentially efficient photocatalyst.However,the synthetic process conditions have a significant impact on the properties of the material,so it is very crucial to improve the photocatalytic performance through the regulation of the synthesis process.This issue mainly focuses on the influence of the synthesis process of Zn_0.2Cd_0.8S solid solution material on its structure and performance,to study different synthesis methods to prepare Zn_0.2Cd_0.8S solid solution material with different morphologies,and studied the effects of change of the parameter on the morphology of product structure in the reaction process,further deeply analyzes the influence of the change of the structure on the photocatalytic properties.The main research content is carried out in the following four aspects:?1?Zn_0.2Cd_0.8S solid solution nanomaterials were prepared by one-step hydrothermal method,the synthesized material is a spherical assembly of particles with a diameter of about 400 nm.Then studied the product of the reaction time and reaction temperature on the synthesis of phase morphology and photocatalytic performance impact of the results summarized as follows:the reaction conditions control at 180°C/6 h by changing the reaction time and reaction temperature?reaction exists in the process of mixed phase?,which indicated the photocatalytic degradation of Rh B performance reached about 65%.?2?The nanorod assembled three-dimensional?3D?hierarchical Zn_0.2Cd_0.8S microspheres were successfully prepared by a facile one-pot microwave hydrothermal approach using ethylenediamine?EN?as the template agent.The optimal 3D hierarchical Zn_0.2Cd_0.8S microspheres?ZCS-30?were obtained when adding 30 mL into the synthetic system,and which can function as a highly active photocatalyst for H₂ evolution under visible-light irradiation with wavelength of420 nm,delivering an activity approximately 2.5 and 7.5 times higher than that of ZCS-0 nanoparticles and CdS counterparts,respectively,and giving an apparent quantum efficiency?AQE?of 7.4%.Furthermore,the ZCS-30 photocatalyst shows good stability due to there is no obvious loss of catalytic activity after the catalytic H₂ evolution for 15 h?5 cycles?.In addition,the ZCS-30 photocatalyst exhibits the excellent degradation of Rhodamine B?Rh B?almost reached 80%under the visible light irradiation over a period of 150 min.Results demonstrate that ZCS-30 can serve as a promising visible-light-driven bifunctional photocatalysts for water splitting and dye degradation.?3?The vane-like Zn_0.2Cd_0.8S solid solution materials were prepared by one-step hydrothermal method.The effects of different HF addition amounts on the phase,morphology and photocatalytic hydrogen production performance of the synthesized sample were studied.In addition,the Zn/Cd ratio of materials were changed to prepare the different proportion of Zn_xCd_1-xS of solid materials under the optimal amount of HF.Results exhibit that compared with pure ZCS-0 material,the addition of HF makes Zn_0.2Cd_0.8S crystal material growth occur along?002?crystal plane orientation,result in mopography has obvious different,and the performance has huge ascension.Moreover,the crystal material Zn_0.2Cd_0.8S still had the best performance when the Zn/Cd ratio was changed.Finally,the cyclic stability of ZCS-0.8 sample was tested,and after three cycles,the yield remained at 98.6%,indicating that ZCS-0.8 class of blade-like solid solution materials have excellent photocatalytic hydrogen production performance and optical stability under visible light irradiation.?4?The Zn_0.2Cd_0.8S/rGO materials were prepared by two step hydrothermal method,mainly study the different GO addition quantity for the influence of the morphology and structure of the sample,and then change the material of photocatalytic hydrogen production performance.Results exhibit that the hydrogen production rate of the sample ZCS-G?1.5?is 2.64 times of the sample?ZCS-G?0??,a solid solution material Zn_0.2Cd_0.8S that prepared at the same reaction conditions.Further,we conducted a cyclic test and found that it still have excellent stability after 3 cycles?12 h?of cyclic test under the same reaction condition,it indicates ZCS-G?1.5?sample has excellent stability.The above results show that ZCS-G?1.5?material can be served as a photocatalyst with a promising application prospect for splitting of water under visible light.