Synthesis of Silicate‐Bridged Heterojunctional SnO₂/BiVO₄ Nanoplates as Efficient Photocatalysts to Convert CO₂ and Degrade 2,4‐Dichlorophenol

Abstract

Bismuth vanadate (BiVO4) is a promising visible‐light responsive photocatalyst, whose photocatalytic activity can be significantly improved by increasing its surface area and utilizing its high‐energy‐level photogenerated electrons effectively. In this work, 2D BiVO4 nanoplates with large specific surface area are successfully fabricated by hydrothermal conversion with the pre‐prepared BiOCl nanosheets as precursors. To improve the photogenerated charge separation, resulted BiVO4 nanoplates are further coupled with nanocrystalline SnO2 to construct heterojunctions, then silicate bridges are introduced between the interfaces of BiVO4 and SnO2. The amount‐optimized silicate‐bridged SnO2/BiVO4 nanocomposite exhibit exceptional visible‐light photocatalytic activities, by ≈7‐time and 4‐time enhancements for CO2 conversion to CH4 and for 2,4‐dichlorophenol degradation, respectively, compared to bare BiVO4 nanoparticles. The significantly enhanced charge separation is verified by steady‐state and time‐resolved surface photovoltage responses and produced hydroxyl radical amounts. Moreover, it is deduced through designed photo‐electrochemical experiments that the introduced SnO2 acts as a proper‐energy platform capable of accepting the photogenerated electrons of BiVO4 nanoplates, and the constructed silicate bridges further facilitate the electron transfer between BiVO4 and SnO2. This work opens up a feasible route to synthesize visible‐light‐driven 2D bismuth‐based nano‐photocatalysts with high photocatalytic activities for efficient fuel production and environmental remediation.

Synthesis of Si–O-Bridged g-C3N4/WO3 2D-Heterojunctional Nanocomposites as Efficient Photocatalysts for Aerobic Alcohol Oxidation and Mechanism Insight

“…Except for the peak intensity, the C 1s and N 1s spectra of 10CN-WO and 10CN-0.5Si-WO show negligible differences from those of pristine CN nanosheets (Figure S4c,d). As shown in Figure , for the samples with the silicate group introduced, the Si 2p peaks at 102.7 eV could be observed, which further verified the successful introduction of silicate groups …”

Visible-Light-Driven Photocatalytic Activity of SnO2–ZnO Quantum Dots Anchored on g-C3N4 Nanosheets for Photocatalytic Pollutant Degradation and H2 Production

“…Using the ultraviolet–visible (UV–vis) diffuse reflection spectrum (DRS), the band gaps of all samples were estimated according to the equation E g = 1240/λ, where E g is the band gap energy and λ is the absorption wavelength. 37 The absorption onsets were observed at approximately 459, 455, and 450 nm for the g-C 3 N 4 , Z/g-C 3 N 4 , and SZ/g-C 3 N 4 photocatalysts, respectively. The SZ/g-C 3 N 4 had better photoresponse and absorption intensity than g-C 3 N 4 and Z/g-C 3 N 4 samples.…”

Bismuth‐Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

“…[121] Recently,X ie and co-workersr eported defective single-unit-cell bismuth vanadate layers for solar CO 2 reduction. [191] The composition-optimized SnO 2 /BiVO 4 nanocomposite exhibited exceptional visible-light photocatalytic activities for CO 2 -to-CH 4 conversion and 2,4-dichlorophenol degradation. The above discussion demonstrates why BiVO 4 is aw idely known photocatalyst for photocatalytic CO 2 reduction in al iquid-phasereaction.…”

“…[190] For instance, N-and Fe-doped BiVO 4 showed increased visible-light absorption and enhanced photoinduced carriers eparation efficiency.C ompared with pure or single-doped BiVO 4 ,N ÀFeÀ BiVO 4 exhibited substantially improved visible-light activity for CO 2 reduction, witht he highest quantum efficiency of 1.86 % for hydrocarbong eneration.B iVO 4 was also coupledw ith nanocrystalline SnO 2 to construct heterojunctions, and silicate bridgesw ere introduced between the interfaces of BiVO 4 and SnO 2 . [191] The composition-optimized SnO 2 /BiVO 4 nanocomposite exhibited exceptional visible-light photocatalytic activities for CO 2 -to-CH 4 conversion and 2,4-dichlorophenol degradation. The enhanced photoinduced carrier separation efficiency was demonstrated by the surfacep hotovoltage response, as well as in ah ydroxyl radicalq uantificatione xperiment.…”