Wang Ji-Chao, Zhang Lin, Fang Wen-Xue, Ren Juan, Li Yong-Yu, Yao Hong-Chang, Wang Jian-She, Li Zhong-Jun
†College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450052, China.
‡Department of Chemistry, Zhengzhou Normal University, Zhengzhou 450044, China.
ACS Appl Mater Interfaces. 2015 Apr 29;7(16):8631-9. doi: 10.1021/acsami.5b00822. Epub 2015 Apr 16.
Hematite-cuprous oxide (α-Fe2O3/Cu2O) nanocomposites are synthesized based on the design of Z-scheme photocatalyst for CO2 reduction. The band structure for the typical Fe2O3/Cu2O (with 1:1 mole ratio) is characterized by UV-vis reflectance spectroscopy and X-ray/ultraviolet photoelectron spectroscopy, and its heterojunction is determined to be Type II band alignment. The photoreduction CO2 activities of the heterostructures are investigated in the presence of water vapor. The CO yields are changed with Fe/Cu mole ratio, and the maximal CO yield attains 5.0 μmol·g cat(-1) after 3 h of visible-light irradiation. Besides the effect of light wavelength, H2O/CO2 molar ratio and temperature on the products is studied. The selectivity of the prepared catalysts is tunable by modulating the light wavelength. The reaction mechanism is proposed and further confirmed experimentally. The results gained herein may provide some insights into the design of Z-scheme photocatalysts for CO2 reduction.
基于Z型光催化剂用于二氧化碳还原的设计，合成了赤铁矿-氧化亚铜（α-Fe2O3/Cu2O）纳米复合材料。通过紫外可见反射光谱和X射线/紫外光电子能谱对典型的Fe2O3/Cu2O（摩尔比为1:1）的能带结构进行了表征，并确定其异质结为II型能带排列。在水蒸气存在的情况下研究了异质结构的光催化还原二氧化碳活性。一氧化碳产率随铁/铜摩尔比的变化而变化，在可见光照射3小时后，最大一氧化碳产率达到5.0 μmol·g cat(-1)。此外，还研究了光波长、H2O/CO2摩尔比和温度对产物的影响。通过调节光波长可以调节所制备催化剂的选择性。提出了反应机理并通过实验进一步证实。本文所得结果可为设计用于二氧化碳还原的Z型光催化剂提供一些见解。
