Abstract:
In addition to the intrinsic driving force of photocatalysis, the external thermal field from the photothermal effect can provide additional energy to the photo-catalytic system to improve the photo-catalytic hydrogen-evolution (PHE) efficiency. Herein, based on the results of density functional theory, we designed and constructed a hollow core-shell FeNi2S4@Mn0.3Cd0.7S (NFS@MCS) S-scheme heterojunction with a photothermal effect, thereby realising a significant enhancement of the PHE performance due to the thermal effect, S-scheme heterojunction and hollow core-shell morphology. As a light collector and heat source, the hollow NFS could absorb and convert photons into heat, resulting in the increased local temperature of photocatalyst particles. Moreover, the S-scheme charge path at the interface not only improved the carrier separation efficiency but also retained a higher redox potential. All these are favourable to increase the PHE activity. The PHE tests show that 0.5 %-NFS@MCS exhibits the highest PHE rate of 17.11 mmol·g-1·h-1, 7.7 times that of MCS. Moreover, through a combination of theoretical calculation and experimental evidence, the PHE mechanism of the NFS@MCS system is discussed and clarified in-depth.
摘要:
除了光催化的内在驱动力,例如,来自光热效应的外部热场可以向光催化系统提供额外的能量,以提高光催化析氢(PHE)效率。在这里,基于密度泛函理论的结果,我们设计并构造了具有光热效应的空心核壳FeNi2S4@Mn0.3Cd0.7S(NFS@MCS)S方案异质结,因此,由于热效应,实现了PHE性能的显着增强,S-方案异质结和中空核壳形态。作为光收集器和热源,空心NFS可以吸收光子并将其转化为热量,导致光催化剂颗粒的局部温度升高。此外,界面处的S方案电荷路径不仅提高了载流子分离效率,而且还保持了较高的氧化还原电位。所有这些都有利于增加PHE活性。PHE测试表明,0.5%-NFS@MCS的PHE最高率为17.11mmol·g-1·h-1,是MCS的7.7倍。此外,通过理论计算和实验证据相结合,对NFS@MCS系统的PHE机制进行了深入的讨论和阐明。