Synthesis Of TiO₂ By Water Hyacinth Templated With Arsenic Self-doping And Its Arsenic Removal

Currently,the preparation of materials has entered the new stage of targeted synthesis the from the initial stage of simple synthesis.The biological template method has gradually become one of the hot research points in the synthesis of new materials due to its characteristics of controllable product morphology and simple and environmentally friendly synthesis process.Because of the own physiological characteristics of some organic organisms,they can be directly cultivated in the process of preparing materials when they were used as templates,which can realize self-doping of specific elements in the material.Taking advantage of the self-doping characteristics of biological templates,this paper achieves self-doping modification of arsenic in water hyacinth template TiO₂using three different experimental methods and applies it to the removal of arsenic in water.In this paper,the following three experimental methods are used for the water hyacinth template:（1）Arsenic standard solution self-doping method:the water hyacinth is cultivated with the arsenic standard solution,and the template material’s active self doping for arsenic is realized by the enrichment of water hyacinth to arsenic ion in water;（2）Self-doping method of immersed arsenic standard solution:in the process of water hyacinth template pre-treatment,the standard solution of arsenic is immersed to achieve self-doping of arsenic elements in the material;（3）the actual water cultivation doping method:the actual water body（hot spring water）containing arsenic is used to cultivate the water hyacinth,and the arsenic ion enrichment performance of the water hyacinth is used to realize the template’s active self-doping of the arsenic element.The materials that have been made were characterized by XRD,N2 adsorption-desorption,SEM,UV-VIS DRS,element analysis and so on.The results show that the materials synthesized by the three experimental methods mentioned above completely reproduced the original morphology of water hyacinth template and successfully realized self doping of arsenic element.In the study of the arsenic removal performance of the material,this paper studies the effects of the reaction time,p H value,and the influence of concentration of the target solution on the arsenic removal performance of the material;the best performance of the material made by the self-doping in arsenic standard solution method is TiO₂-stem-hydroponic cultivation（III）,its photo catalytic oxidation arsenic removal rate can reach82%,compared with the material without self-doping,its arsenic removal performance increased by one time and was better than P25,and the material synthesized by this method has selective adsorption performance for arsenic ion;The best performance of materials made in immersing self-doping method is TiO₂-stem-immersion（III）,its photo-catalytic oxidation arsenic removal rate reached 70%,compared with the material without doping,its arsenic removal performance is improved by 32%and was better than P25;the best material synthesized by the self-doping method with actual water as the solution was TiO₂-stem-spring water,and its photo-catalytic oxidation arsenic removal rate can reach 80%,compared with the material without doping,the arsenic removal performance increased by one time and was better than P25.The materials mentioned above have excellent photo-catalytic oxidation activity when the target solution p H is 5 and 3,and the material is more suitable for the treatment of low concentration water with an arsenic concentration of 0.1-1 mg/L.Combined with the experimental results,the arsenic self doping water hyacinth TiO₂ mesoporous materials can be successfully synthesized,and it has certain photo-catalytic oxidation arsenic removal performance.