Ag_(2)CrO_(4)/g-C_(3)N_(4)复合材料光催化产氢性能及机理  

Mechanism and photocatalytic hydrogen production performance of Ag_(2)CrO_(4)/g-C_(3)N_(4) composites

作　　者：芦涛 张安超[1] 孙志君[1] 陈国艳[1] 张倩倩 敬曼曼 倪飞翔 LU Tao;ZHANG Anchao;SUN Zhijun;CHEN Guoyan;ZHANG Qianqian;JING Manman;NI Feixiang(School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]河南理工大学机械与动力工程学院,河南焦作454003

出　　处：《功能材料》2024年第6期6128-6137,共10页Journal of Functional Materials

基　　金：国家自然科学基金项目(51676064);河南省自然科学基金项目(232300420082);河南理工大学创新型科研团队项目(T2020-3)。

摘　　要：采用原位化学沉积法制备了一系列具有光催化产氢性能的Ag_(2)CrO_(4)/g-C_(3)N_(4)复合材料。利用X射线衍射、傅里叶变换红外、场发射扫描电子显微镜、透射电子显微镜、X射线光电子能谱明确了复合物的物相组成、官能团结构、微观形貌、元素组成及其存在形态。采用紫外可见光漫反射、光致发光光谱和光电流测试探究了复合材料光吸收性能及光生载流子的分离情况,研究了光催化剂的产氢性能及其影响因素。结果表明,Ag_(2)CrO_(4)的引入不会改变g-C_(3)N_(4)原有的碳氮杂环结构,且Ag_(2)CrO_(4)以纳米颗粒形式分散于g-C_(3)N_(4)表面。虽然Ag_(2)CrO_(4)没有产氢效果,但随着Ag_(2)CrO_(4)含量的增加,复合材料的产氢速率先增大后减小。最优光催化剂Ag_(2)CrO_(4)/C_(3)N_(4)-4%的产氢速率是纯g-C_(3)N_(4)的2.7倍,其原因可能是Ag_(2)CrO_(4)和g-C_(3)N_(4)的耦合形成了Z型异质结,拓宽了g-C_(3)N_(4)的可见光响应范围,降低了电荷转移的阻抗,促进了光生载流子的迁移和分离。A series of Ag_(2)CrO_(4)/g-C_(3)N_(4) composites with photocatalytic hydrogen(H_(2))production were prepared by in-situ chemical deposition method.The phase composition,functional group structure,microscopic morphology,elemental compositions and their species of the composites were characterized using X-ray diffraction,Fourier transform infrared,field emission scanning electron microscope,transmission electron microscope and X-ray photoelectron spectroscopy.The light absorption properties and photogenerated carrier separation of the samples were investigated by UV-visible diffuse reflectance spectra,photoluminescence spectroscopy and photocurrent testing.The H_(2) production performance of the photocatalysts and the influencing factors were investigated experimentally.The results showed that the introduction of Ag_(2)CrO_(4) did not change the originally heterocyclic structure of g-C_(3)N_(4),and nanostructure Ag_(2)CrO_(4) was dispersed on the surface of g-C_(3)N_(4).Although Ag_(2)CrO_(4) had no H_(2) production effect,the H_(2) production rate of the composite increased first and then decreased with the increase of Ag_(2)CrO_(4) content.The H_(2) production rate of the optimal photocatalyst Ag_(2)CrO_(4)/C_(3)N_(4)-4%was 2.7 times that of pure g-C_(3)N_(4).The reason was mainly attributed to the appearance of Z-type heterojunction between of Ag_(2)CrO_(4) and g-C_(3)N_(4),which broadened the visible light response range of g-C_(3)N_(4),reduced the charge transfer impedance,and promoted the separation and migration of photogenerated carriers.

关 键 词：氮化碳 铬酸银 异质结 光催化剂 产氢 

分 类 号：TQ116.2[化学工程—无机化工]