Facile Synthesis of CeO₂ Nanosheets Decorated upon BiOI Microplate: A Surface Oxygen Vacancy Promoted Z-Scheme-Based 2D-2D Nanocomposite Photocatalyst with Enhanced Photocatalytic Activity

Abstract

Construction of a visible light driven Z-schemebased photocatalytic system is a hot topic of research because of the potential to alleviate both energy and environmental issues. In the present study a series of surface vacancy mediated BiOI−CeO 2 nanocomposites were prepared and their crystallographic, morphological, optical, and electrochemical behavior were characterized through XRD, TEM, FESEM, UV−vis DRS, PL, ESI, and Mott−Schottky techniques. From the XPS analysis, it could be said that a high amount of oxygen defects and metallic bismuth were present on the composite than neat CeO 2 which was the major cause of enhancement in the photocatalytic activity. Further the photocatalytic efficiency of the as prepared samples was tested toward RhB decolorization/phenol oxidation as well as for O 2 gas evolution. It was observed that 40 wt % BiOI−CeO 2 nanocomposite exhibited highest photocatalytic activity among neat and other composites, i.e., 89% decolorization of 100 ppm RhB and produces 323 μmol/2h of O 2 under visible light illumination. To justify the enhanced photocatalytic activity of the material a Z-scheme-based charge transfer mechanism was proposed. Where surface oxygen vacancy exists on CeO 2 , I 3 − /I − reversibility pair through Bi metal on BiOI, scavenger experiment, PL spectra, and Nyquist plot provide solid evidence toward a Z-scheme charge transfer pathway. This work will provide some useful information in course of developing of Z-scheme-based photocatalyst without an external mediator.

Enhancement of Solar‐Driven Photocatalytic Activity of BiOI Nanosheets through Predominant Exposed High Energy Facets and Vacancy Engineering

“…However, the peaks of Bi 4f and I 3d in BiOI nanosheets shifted slightly compared with that of BiOI nanoplates, indicating the formation of the oxygen vacancies . These result was similar to the previous one . Obvious difference in the high resolution XPS of O 1s was observed between BiOI nanoplates and BiOI nanosheets, as shown in Figure 2c.…”

“…The peak at around 529.6 eV is attributed to the Bi‐O bonds in [Bi 2 O 2 ] slabs of BiOI. The other two peaks at around 531.0 and 532.2 eV are assigned to the surface hydroxyl group and oxygen vacancy . Interestingly, the oxygen vacancy peak in BiOI nanosheets is higher than that of BiOI nanoplates.…”

Construction of a Z-Scheme Dictated WO3–X/Ag/ZnCr LDH Synergistically Visible Light-Induced Photocatalyst towards Tetracycline Degradation and H2 Evolution

“…14 So, it has enormous potential to be applied for water splitting reaction and environmental pollutant elimination. To date, a number of Z-scheme-based visible light photocatalytic systems have been reported, such as CeO 2 /BiOI, 15 Cu/MoO 3 -g-C 3 N 4 , 16 and LaFeO 3 /g-C 3 N 4 17 possessing much better photocatalytic abilities than single photocatalysts.…”

2D/2D heterostructured photocatalyst: Rational design for energy and environmental applications

“…In addition to the above discussed in coupling with g-C 3 N 4 , the bismuth-based 2D layer materials can also be hybrided with other 2D photocatalysts to form 2D/2D heterojunction for the degradation of pollutes. Sultana et al [107] reported a composite of 2D-CeO 2 with 2D BiOI to form a Z-scheme heterojunction for RhB dye decolorization and phenol degradation. In another study, Xu's group [91] designed Au nanoparticles (NPs)-decorated 2D/2D Bi 2 WO 6 -TiO 2 heterostructure (Fig.…”