Oxygen Vacancy Induced Atom-Level Interface in Z-Scheme SnO₂/SnNb₂O₆ Heterojunctions for Robust Solar-Driven CO₂ Conversion

Abstract

The modulation of Z-scheme charge transfer is essential for efficient heterostructure toward photocatalytic CO2 reduction. However, constructing a compact hetero-interface favoring the Z-scheme charge transfer remains a great challenge. In this work, an interfacial Nb–O–Sn bond and built-in electric field-modulated Z-scheme Ov-SnO2/SnNb2O6 heterojunction was prepared for efficient photocatalytic CO2 conversion. Systematic investigations reveal that an atomic-level interface is constructed in the Ov-SnO2/SnNb2O6 heterojunction. Under simulated sunlight irradiation, the obtained Ov-SnO2/SnNb2O6 photocatalyst exhibits a high CO evolution rate of 147.4 μmol h–1 g–1 from CO2 reduction, which is around 3-fold and 3.3-fold of SnO2/SnNb2O6 composite and pristine SnNb2O6, respectively, and favorable cyclability by retaining 95.8% rate retention after five consecutive tests. As determined by electron paramagnetic resonance spectra, in situ Fourier transform infrared spectra, and density functional theory calculations, Nb–O–Sn bonds and built-in electric field induced by the addition of oxygen vacancies jointly accelerate the Z-scheme charge transfer for enhanced photocatalytic performance. This work provides a promising route for consciously modulating Z-scheme charge transfer by atomic-level interface engineering to boost photocatalytic performance.

Urchin-like TiO2/CdS Nanoparticles Forming an S-scheme Heterojunction for Photocatalytic Hydrogen Production and CO2 Reduction

“…To further improve the photocatalytic ability of TiO 2 , researchers recently studied a series of new catalysts for photocatalytic H 2 and CO 2 reduction reactions, such as 3D/2D TiO 2 @Ti 3 C 2 MXene/Bi 2 S 3 , TiO 2 /C 3 N 4 , 3D ZnIn 2 S 4 /TiO 2 and so on. Of course, some scholars use the advantages of precious metals in catalysis to improve the performance of catalysts by incorporating Pt, Au, and Ag. , In addition, the performance of the TiO 2 catalyst was also improved by designing the morphology of composite materials, , Z-scheme heterojunctions, , and p–n heterojunctions . However, there are few research studies on S-scheme heterojunction catalysts constructed with cheap inorganic materials and even fewer research studies on catalysts that can photocatalyze both H 2 production and CO 2 reduction …”