氮掺杂石墨烯与g-C3N4二维异质体对纳米Fe2O3光催化剂的复合改性

使用相分离的水解-溶剂热法制备了α-Fe₂O₃纳米粒子, 通过简单的湿化学法实现了质量分数为3%的石墨烯、 氮掺杂石墨烯和g-C₃N₄ 3种二维异质体对纳米α-Fe₂O₃的复合改性, 并比较了3种二维异质体对α-Fe₂O₃光催化活性的影响. 结果表明, 在光催化还原二氧化碳和降解液相苯酚过程中, 二维异质体的复合均提高了纳米α-Fe₂O₃的光催化活性, 氮掺杂石墨烯对α-Fe₂O₃的改性效果优于石墨烯, 其中g-C₃N₄对α-Fe₂O₃的改性效果最优. 通过表面光电压谱、 光电化学及羟基自由基等测试, 确认二维异质体的复合改性主要通过促进纳米α-Fe₂O₃的光生电荷分离和提高活性中间组分(羟基自由基)的含量提高纳米α-Fe₂O₃的光催化活性.

Modification of Nano-sized Fe2O3 Photocatalysts with N-doped Graphene and g-C3N4 †

Alpha iron-trioxide (α-Fe2 O3 ) nanoparticles were synthesized by a phase-separated hydrolysis-solvothermal method, and then modified by coupling 3%( mass fraction) graphene, nitrogen-doped graphene and g-C3 N4 as the two-dimensional hetero-materials by a simple wet chemical process. Detailed comparative studies of their effects on photocatalytic activities of α-Fe2 O3 were carried out. The results show that the photocatalytic activities of nano α-Fe2 O3 for reducing CO2 to CO and for degrading phenol are enhanced after coupling with all two-dimensional hetero-materials. The modification of nitrogen-doped graphene onα-Fe2 O3 is better than graphene and the modification of g-C3 N4 on α-Fe2 O3 is the best. Based on the measurements of surface photovoltage responses, photoelectrochemical curves, and hydroxyl radical amounts, it is confirmed that the introduction of two-dimensional hetero-materials would promote the photogenerated charge separation and increase the content of the active intermediate( hydroxyl radicals) consequently, leading to the improved photocatalytic activity of nano α-Fe2O3.