Design And Mechanism Study Of Photocatalytic-photothermal Synergistic Antibacterial System Based On MOFs

The influence of bacteria or germs on the environment of human living and people's health problems is becoming more and more serious.Antibacterial methods in the traditional sense: ultraviolet sterilization,high temperature sterilization,disinfection water and antibiotics,etc.,because of their high energy consumption,long time,poor effect and bacterial resistance and other shortcomings,resulting in the inability to effectively inhibit and kill bacteria.And it will be accompanied by the generation of secondary pollution,which is not conducive to human production and life.Photocatalytic technology has been widely used as a green,efficient,economical and environmentally friendly sterilization technology.However,the development and application of photocatalytic technology are limited due to the poor light absorption properties and low quantum efficiency of semiconductor materials.The research found that by coupling with light and heat,the deficiency of photo-catalysis can be made up,the effective use of sunlight can be achieved,and further promote the development of photocatalytic technology.At present,the photo-thermal photocatalytic system is usually a combination of photo-thermal materials and semiconductor photo-catalysts.Commonly,there are metals,oxides and carbon materials with photo-thermal properties combined with semiconductors.Unfortunately,the research on synergistic photo-thermal and photocatalytic technology in the field of antibacterial is not systematic,especially in terms of antibacterial mechanism.In this paper,based on MOFs catalysts,bimetallic metal organic framework antibacterial materials with good photo-thermal properties were designed and researched,and the synergistic photo-thermal and photocatalytic antibacterial effect was explored.More importantly,based on photo-thermal metal-organic frameworks,we systematically research and demonstrate their synergistic photo-thermal and photocatalytic antibacterial mechanism.Therefore,it provides the possibility for large-scale practical application of photo-thermal and photocatalytic technology.The main research features in this paper are:(1)The co-introduction of two metals,cobalt and copper,into the framework structure of MOFs was successfully achieved by a one-pot method,which effectively improved the photocatalytic and photo-thermal performance of the catalyst.Meanwhile,the impact of the proportion of the two metals on the photo-thermal and optical properties of the sample was studied more systematically,and it was concluded that when the Co/Cu molar ratio was 3:2,the photo-thermal and optical properties of the sample were the best.The specific performance for the samples is significantly enhanced light absorption capacity,increased photo-thermal effect,and improved photo-thermal conversion efficiency,and the recombination of photogenerated carriers is more effectively inhibited under the action of light and heat,thereby achieving the efficient inactivation and mineralization of bacteria.This work demonstrates the significance of bimetallic MOFs in photocatalytic and photo-thermal synergy for future environmental sterilization.(2)Based on the synergistic photo-thermal and photocatalytic effect,we systematically analyzed and demonstrated the bacterial death and mineralization mechanisms based on the Cu-CAT-1 sample.The synergistic effect of photothermal-photocatalysis exhibits more efficient bacterial inactivation and mineralization properties compared to thermal action and photocatalysis alone,due to thermal effects,light-induced and material Fenton-like properties,and the bacterial self-protection system is wrecked so that the expression of hydrogen peroxide in the bacteria cannot be inhibited,resulting in a sharp increase in the content of ROS,thereby achieving efficient bacterial death and mineralization.The specific manifestations are the damage of bacteria from the membrane,the leakage of protein and potassium ions,the inactivation of enzymes in bacteria,and the decomposition of RNA and DNA.These effective evidences fully corroborate the synergistic photo-thermal and photocatalytic antibacterial mechanism of this system.Similarly,this also provides a theoretical basis for how the follow-up photo-thermal and photocatalytic sterilization technology can efficiently achieve sterilization and mineralization.