Achieving Direct Z-Scheme Charge Transfer through Constructing 2D/2D α-Fe₂O₃/CdS Heterostructure for Efficient Photocatalytic CO₂ Conversion

Abstract

Heterostructure construction is an effective performance regulation method for photocatalytic field, while its application in solar-driven CO 2 conversion is highly restricted by inevitably sacrificing the stronger redox ability of photoinduced charges. Herein, a well-designed α-Fe 2 O 3 @CdS bilayer heterostructure with ultrathin two-dimensional (2D) shape and sufficient interface contact is deliberately constructed by a two-step solvothermal method. Effective interfacial electronic coupling as well as highly enhanced photoinduced charge separation and elongated photoelectron lifetime are implemented in this nanohybrid. Such 2D/2D heterostructure exhibits much more efficient photocatalytic CO 2 conversion than bare CdS and α-Fe 2 O 3 . The direct Zscheme charge transfer path and dynamics achieved by favorable internal built-in electric field (IEF) at heterointerface mainly contribute to the excellent photocatalytic CO 2 reduction performance. The evident work function difference as well as the large heterointerface area and short carrier diffusion distance to interface between 2D CdS and 2D α-Fe 2 O 3 contribute to the favorable IEF. This work provides a deep understanding of the construction and interface electronic mechanism of the direct Z-scheme heterostructure for application in future solar energy conversion.

Optimizing the Reaction Pathway by Active Site Regulation in the CdS/Fe2O3 Z-Scheme Heterojunction System for Highly Selective Photocatalytic Benzylamine Oxidation Integrated with H2 Production

“…To enhance the N-benzylidenebenzylamine product selectivity, Pt nanoparticles are loaded on this CdS/Fe 2 O 3 Z-scheme heterojunction by in situ photo-reduction of H 2 PtCl 6 . Density 26,31,32 The crystal structures and phase compositions of the fabricated samples were analyzed by the X-ray diffraction (XRD) patterns (Figure 2a). The prepared CdS and CdS/ Fe 2 O 3 composites all exhibit six XRD peaks at around 25.6, 26.9, 29.0, 43.9, 48.4, and 52.3°, which are corresponding to the (100), (002), (101), (110), (103), and (112) facets of hexagonal CdS, respectively.…”

Construction of strongly coupled 2D–2D SnS2/CdS S-scheme heterostructures for photocatalytic hydrogen evolution

“…CdS nanosheets (CdS NSs) were synthesized through a hydrothermal method. 30 Specifically, 0.8 g of Cd(Ac) 2 ·2H 2 O and 0.87 g of NH 2 CSNH 2 were dispersed in 30 mL of ethylenediamine under magnetic stirring and then the solution was transferred to a 50 mL Teflon-lined autoclave and maintained at 100 °C for 12 h. After cooling naturally to room temperature, the yellow powder was centrifuged and washed with distilled water, and then dried in air at 60 °C.…”

Advanced hematite nanomaterials for newly emerging applications

“…1a, in the past decade, publications concentrating on a-Fe 2 O 3 presented a steadily increasing trend, which also implied that the associated materials have always been a research hotspot. Additionally, in very recent years, because of the rich physicochemical properties and/or multifunctionalities, a-Fe 2 O 3 materials were also demonstrated to show signicant breakthroughs in some frontier applications/elds including but not limited to electrocatalysis, 29,30 photocatalytic carbon dioxide (CO 2 ) reduction, 31 some specic photoelectrochemistry reactions, 32 chemical sensing, 33 and biological medicine (Fig. 1b).…”