可见光驱动Z-scheme g-C3N4/α-Fe2O3催化剂高效产H2  

Constructing Z-scheme g-C3N4/α-Fe2O3 photocatalysts and efficient H2 generation by visible-light driven

作　　者：王宇晶[1] 宋荷美 张新东 柴守宁 WANG Yujing;SONG Hemei;ZHANG Xindong;CHAI Shouning(School of Materials Science and Chemical Engineering, Xi’an Technological University, Xi’an 710021, China;School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi’an 710055, China)

机构地区：[1]西安工业大学材料与化工学院,西安710021 [2]西安建筑科技大学环境与市政工程学院,西安710055

出　　处：《功能材料》2020年第1期1009-1015,共7页Journal of Functional Materials

基　　金：国家杰出青年科学基金资助项目(51508435,21507103);金川公司-西安建筑科技大学预研基金资助项目(YY1507)

摘　　要：作为一种新型的具有可见光响应的半导体光催化剂,g-C3N4在光催化产氢领域得到了广泛的研究。然而,纯g-C3N4存在可见光响应范围较窄、光生电子-空穴复合率高、量子效率低等问题。针对纯g-C3N4的缺陷,采用简单的水热合成法制备出一种高效纳米晶胶体g-C3N4/α-Fe2O3复合材料。为了检测g-C3N4/α-Fe2O3的光催化产氢性能,将其引入以NaBH4为底液的体系中。结果表明,当Fe质量分数为1%,体系温度为30℃、NaBH4浓度为50 mmol/L时,产氢量为30 mL。利用PL、EIS以及PC等手段对g-C3N4/α-Fe2O3的光电响应能力进行了分析。结果表明,g-C3N4/α-Fe2O3复合材料具有较低的光致发光强度、较高的光电流密度和较小的电荷转移电阻,说明了光生电荷载流子的有效分离和快速转移。另外,Z-scheme电荷转移途径赋予了g-C3N4/α-Fe2O3较强的氧化能力,为光催化裂解NaBH4提供了较大的驱动力。主要意义在于对光催化产氢有一个新认识,为合理设计和构建Z型光催化剂提供参考。The graphite phase carbon nitride(g-C3N4)photocatalyst has attracted widespread attention owing to its excellent photocatalytic activity for H2 production.However,there are also some disadvantages for single g-C3N4,such as narrow visible light response,high electron-hole recombination efficiency and low quantum efficiency.Herein,an efficient nanocryatalline colloidal Z-scheme g-C3N4/α-Fe2O3was fabricated rationally by a simple hydrothermal method for H2 evolution under visible light.NaBH4 was used as a based fluid to investigate the catalytic performance,and the corresponding generation H2 rate reached to 30 mL after 10 min under the optimum pH=12,Fe 1%of the mass fraction and 30℃of the solution temperature.The photoelectric response ability of g-C3N4/α-Fe2O3 was analyzed by means of PL,EIS and PC.The results show that the composite had the lower photoluminescence intensity,higher photocurrent density and smaller charge transfer resistance,indicating the effective separation and rapid transfer of photogenerated charge carriers.The results demonstrate that the Z-scheme carrier transfer pathway endowed g-C3N4/α-Fe2O3 composite with strong oxidation ability,which provided a greater driving force for photocatalytic cracking of NaBH4.The main significance of this study gave an new insights into photocatalytic H2 production and provided a reference for rationally designing and constructing Z-scheme photocatalyst.

关 键 词：光催化剂 Z-型g-C3N4/α-Fe2O3 可见光响应 光生电子-空穴对 

分 类 号：TK91[动力工程及工程热物理]