g-C_(3)N_(4)/TiO_(2)复合汽车尾气光催化剂的组成设计与性能评价

Composition Design and Performance Evaluation of g-C_(3)N_(4)/TiO_(2)Composite Vehicle Exhaust Photocatalysts

随着汽车尾气对空气质量的负面影响日益严重,光催化技术在环保领域的应用逐渐受到重视。因此,基于二氧化钛(TiO_(2))和石墨相氮化碳(g-C_(3)N_(4))的光催化性能,制备了一种g-C_(3)N_(4)/TiO_(2)复合光催化剂,旨在提高汽车尾气的降解效率,即:选用三聚氰胺(C_(3)H_(6)N_(6))、双氰胺(C_(2)H_(4)N_(4))和尿素(CH4N2O)作为前驱体制备g-C_(3)N_(4),通过质量损失和尾气降解实验分析筛选出最佳前驱体,并设计了不同质量比的g-C_(3)N_(4)/TiO_(2)复合光催化剂;通过对比分析单体和复合光催化剂的光催化性能,确定了复合光催化剂的最佳质量比。实验结果表明:制备g-C_(3)N_(4)的最佳前驱体为C_(3)H_(6)N_(6),当复合光催化剂的最佳质量比为C_(3)H_(6)N_(6)∶TiO_(2)=2∶1时,复合光催化剂的降解效率达到最佳;g-C_(3)N_(4)/TiO_(2)复合光催化剂在60 min内对HC、CO和NO_(x)的降解率分别为16.12%、16.87%和45.37%,其降解效率明显高于单体TiO_(2)。该研究结果为进一步优化光催化技术提供了有益的参考,有助于推动其在环保领域的应用和发展。

With the increased negative impact of vehicle exhaust to the air pollution year by year,the application of photocatalytic technology has gradually received attention.Therefore,based on the photocatalytic properties of titanium dioxide(TiO_(2))and graphitic carbon nitride(g-C_(3)N_(4)),a g-C_(3)N_(4)/TiO_(2)composite photocatalyst was proposed to improve the efficiency of vehicle exhaust degradation.Melamine(C_(3)H_(6)N_(6)),dicyandiamide(C_(2)H_(4)N_(4)),and urea(CH4N2O)were selected as precursors to prepare g-C_(3)N_(4).The best precursor was selected by mass loss and exhaust degradation test analysis.The g-C_(3)N_(4)/TiO_(2)composite photocatalyst with different mass ratios was designed;The photocatalytic performance of monomer and composite photocatalyst was compared and analyzed to obtain the optimal mass ratio of the composite photocatalyst ultimately.The results show that the optimal precursor for the prepara tion of g-C_(3)N_(4)is C_(3)H_(6)N_(6).The best mass ratio of the composite photocatalyst of C_(3)H_(6)N_(6)∶TiO_(2)is 2∶1,and the degradation efficiency of composite materials is the best;In 60 minutes,the degradation efficiency and HC,CO and NO_(x)was 16.12%,16.87%and 45.37%,respectively by g-C_(3)N_(4)/TiO_(2)composite photocatalyst,the efficiency is obviously higher than that of monomer TiO_(2).This study provides useful reference for further optimizing photocatalytic technology and helps to promote its application and development in the field of environmental protection.