Synergistic Effect Of Two-Dimensional Nanomaterials With Cd_0.5Zn_0.5S For Enhancing Photocatalytic Performance And Its Applications

In today’s world where traditional fossil energy sources are depleted and the ecological environment is getting worse,this thesis focuses on photocatalytic technology for both new energy development and wastewater treatment.To address the scientific problems of poor stability and photocorrosion of Cd S,the basic semiconductor material for photocatalysis,and the easy compounding of photogenerated electron-hole pairs,a composite photocatalytic material system with two-dimensional nanomaterials Mo S₂,MXene Ti₃C₂and graphene as co-catalysts with Cd_0.5Zn_0.5S was designed and investigated to enhance the photocatalytic performance.The main research contents and results of this thesis are as follows.（1）A composite photocatalytic material system with two-dimensional nanomaterial MXene Ti₃C₂ as a co-catalyst in synergy with Cd_0.5Zn_0.5S was synthesized and studied by hydrothermal method and achieved a good photocatalytic performance.Meanwhile,this study expands the application boundary of photocatalysis technology,and its highest efficiency of hydrogen preparation using seawater photocatalysis reaches 9.071 mmol g^-1 h^-1 which is 33times in comparison of the conventional Pt catalytic system.Its performance remained good in photostability tests.In addition,the interfacial engineering modulation between MXene Ti₃C₂ and Cd_0.5Zn_0.5S materials was used in the photocatalytic material design to construct Schottky barriers to reduce the complexation of photogenerated carriers to obtain high-efficiency photocatalysis.This design strategy provides a novel approach for the preparation and application of novel photocatalytic materials.（2）A composite photocatalytic material system with two-dimensional nanomaterial Mo S₂ as co-catalyst and Cd_0.5Zn_0.5S was prepared and studied by hydrothermal synthesis,and good photocatalytic performance was achieved.The demand for heavy hydrogen is increasing with the development of science and technology,but the conventional preparation of heavy hydrogen has the disadvantage of being time-consuming and complicated.The research in this thesis opens up the application field of photocatalytic technology,and its efficient,simple,and green photocatalytic preparation of heavy hydrogen is a very promising strategy.In particular,the photocatalytic preparation of heavy hydrogen is a promising strategy for the controlled fusion of the ultimate energy source"artificial sun",which relies heavily on heavy hydrogen as the basic raw material.The highest efficiency of heavy hydrogen preparation reached 9.745 mmol g^-1 h^-1 and maintained good performance in photostability tests.（3）Given the limitations of industrial production of graphene materials,a high-quality porous graphene material was prepared from waste mangosteen shells as a substrate for large-scale industrial production,and a composite photocatalytic material system with two-dimensional nanomaterial graphene as a co-catalyst and Cd_0.5Zn_0.5S was prepared and studied by hydrothermal synthesis,and good photocatalytic performance was achieved.The photocatalytic elimination efficiency of ciprofloxacin,a hard-to-degrade organic compound,reached 99%in 60 minutes and maintained good performance in the photostability test.（4）Through the continuous improvement of process control and engineering technology,the integrated thermal insulation type photocatalytic self-cleaning antibacterial coating which can be applied to a large area has been developed and successfully applied in several key projects with broad prospects for promotion and application.The thermal insulation temperature difference can reach 15.9 degrees Celsius and the killing rate of typical bacteria such as E.coli can be maintained at more than 99%for 30 minutes.Because of the engineering challenges of large-area catalyst loading that have long limited the development of photocatalytic technology,the integrated thermal insulation photocatalytic self-cleaning antibacterial coating developed in this thesis has been demonstrated and applied in many key projects in different industries with good economic and social benefits,in combination with previous industry-academia research.