Synergistic effect of surface oxygen vacancies and interfacial charge transfer on Fe(III)/Bi2MoO6 for efficient photocatalysis

Novel Fe(III) clusters grafted Bi2MoO6 nanosheets with surface oxygen vacancies (denoted as F/BMO-SOVs) heterostructured composite have been firstly fabricated via a reliable calcination process combined with impregnation approach. The surface oxygen vacancies (SOVs) in Bi2MoO6 were formed due to controlled calcination process. The presence of Fe (III) clusters was confirmed by HRTEM, XPS, and UV-vis DRS. Under visible light irradiation, the optimum molar ratio of 15% F/BMO-SOVs achieved 93.4% degradation efficiency of phenol within 180 min, representing nearly 80 times higher activity than the pure Bi2MoO6, confirmed by both absorption spectrum and TOC measurement. The dramatically enhanced photocatalytic activity is attributed to the synergistic effect between the SOVs, Fe(III) clusters and Bi2MoO6, which not only narrows the band gap, improving the visible light response ability, but also facilitates the direct interfacial charge transfer (IFCT) from the SOVs to the surface Fe(III) clusters, greatly promoting the efficient separation of photogenerated electron-hole pairs. According to the trapping experiments and ESR measurements results, center dot O-2(-), center dot OH, and h(+) all participated in the phenol photodegradation process over F/BMO-SOVs. Thus, this work not only provides a synergistic effect between SOVs, Fe(III) clusters and Bi2MoO6 involving an IFCT process, but also proposes an efficient approach to fabricating highly active photocatalysts in environmental remediation and solar fuel synthesis.