Study On Synthesis And Properties Of Bismuth Based Photocatalysts Based On BiOAc At Low Temperature

Photocatalytic technology is an effective method to solve energy shortage and environmental pollution.Bismuth based photocatalyst semiconductor has attracted more and more researchers' attention in recent years due to its cheap raw material cost,relatively simple manufacturing process and good photocatalytic activity.At present,the bismuth semiconductor photocatalyst mainly improves its performance by improving the preparation process and improves its practicality.A variety of excellent bismuth photocatalysts have been prepared by changing a variety of conditions by using bismuth acetate as the matrix.A series of tests on its photocatalytic performance have been carried out.The specific research contents are as follows:First,monodisperse nanoscale and hierarchical structure of flower like bismuth acetate(CH3COO(BiO);BiOAc)crystals were synthesized by controlling acetic acid and bismuth oxide at room temperature and by adjusting reaction time and reactant addition ratio.On this basis,BiOI/BiOAc heterojunction nanocrystalline is prepared by the reaction of ion exchange and KI in aqueous solution by using the above mentioned bismuth acetate crystal.This study has realized the control of the room temperature of BiOI/BiOAc heterojunction nanocrystals,and provides a new way of thinking for the improvement of the production process.Secondly,based on the above method,continue adding deionized water mixing reaction to bismuthyl acetate completely dissolved after preparing acetic acid bismuth oxide,bismuth oxide acetate formed clear solution,solution of ammonia solution to the right amount of KI as precipitant at room temperature to prepare I-BiOAc.The method belongs to the coprecipitation method.By neutralizing the excess acetic acid in ammonia water and adding a proper amount of iodide ions,the iodide ions are precipitated with the acetate ions at the same time.The photocatalytic activity test of I-BiOAc samples showed that under visible light,I-BiOAc samples had good photocatalytic activity for RhB and malachite green.The photocatalytic properties are much better than BiOI/BiOAc heterojunction nanocrystals that in the first chapter of ion exchange.Finally,based on the above method,The precipitant is replaced by an ammonia solution with a proper amount of KI to a solution with an appropriate amount of KI/KBr or a solution with a proper amount of KI/KCl dissolved in a solution,Reacting to a HAc solution for dozens of minutes,Solid solution of BiOIi1-Br,(x = 0-1)or sheet like BiOI1-xClx(x = 0-1)solid solution was prepared.Among them,BiOI0.75Bro.25 and BiOI0.-75Br0.25 have larger specific surface area and suitable valence band location.Therefore,under visible light irradiation,the photocatalytic activity of MO degradation is better than that of BiOCl,BiOBr,BiOI and other solid solutions.