竹活性炭比表面积及其孔径对TiO_2/BAC光催化降解甲醛性能的影响

Effects of Specific Surface Area and Pore Size of Bamboo Activated Carbon on Photocatalysis of Formaldehyde on TiO_2/BAC

[目的]研究竹活性炭比表面积及其孔径对TiO2/BAC光催化降解甲醛性能的影响。[方法]以竹子为原料,按照不同浸渍比,用磷酸活化法制备不同孔径和比表面积的系列竹活性炭（BAC）作为载体;通过溶胶凝胶法制备负载型光催化剂（TiO2/BAC）,以水溶液中的甲醛作为目标污染物,考察所得的一系列负载型光催化剂的光催化性能;采用氮气吸附、SEM进行表征,研究了竹活性炭的孔径和比表面积对负载型光催化剂性能的影响。[结果]竹活性炭吸附和TiO2光解的协同效应使TiO2/BAC光催化剂对水溶液中甲醛的处理效率显著提高;比表面积较大、微孔较多、平均孔径为2~3 nm的竹活性炭有利于TiO2的负载,制备得到的复合光催化活性较高。[结论]为TiO2光催化剂的固化负载研究提供了理论依据。

[Objective] The aim was to study effects of specific surface area and pore size of bamboo activated carbon on photocatalysis of formaldehyde on TiO2/BAC.[Method] Bamboo,as raw material,was activated with different dosages of phosphoric acid in order to produce bamboo activated carbon（BAC） with different specific surface areas and pore sizes.Composites of TiO2 and bamboo activated carbon（TiO2/BAC） were achieved through sol-gel method,and their photocatalytic performance of TiO2/BAC catalysts was studied by removal of formaldehyde in aqueous solution.Nitrogen adsorption and SEM were used to characterize BACs and TiO2/BACs and to investigate effects of specific surface area and pore size of BAC on the resultant catalysts.[Result] Efficiency of removing formaldehyde from aqueous solution by TiO2/BAC catalysts was increased by the synergistic effect of samboo activated carbon adsorption and TiO2 photolysis significantly.The samboo activated carbon with larger specific surface area,more micropore and average pore diameter between 2 and 3 nm was beneficial to the TiO2 particle supported on the carbon surface,and then the activity of composite photocatalyst was relatively high.[Conclusion] The research provides theoretical basis for studies on TiO2 photocatalyst.