Harnessing self-supported Au nanoparticles on layered double hydroxides comprising Zn and Al for enhanced phenol decomposition under solar light

In Situ Synthesis of Bi2O3 Nanoparticles on ZincMe (Me=Al or Cr) Layered Double Hydroxide Frameworks for Photocatalytic Oxygen Evolution from Water under Solar‐Light Activation

“…The capabilities of the Bi 2 O 3 NPs/LDHs to absorb visible light can contribute to the improved photocatalytic properties . By analogy to the reported AuNPs/LDHs, the characteristic features of Bi 2 O 3 NPs/LDHs can be ascribed to photoinduced interfacial charge transfer through surface modification of ZnAlLDH and ZnCrLDH by the synthesis of Bi 2 O 3 NPs . After calcination, the same phenomena were observed for both Bi 2 O 3 /ZnO/ZnAl 2 O 4 and Bi 2 O 3 /ZnO/ZnCr 2 O 4 , for example, a strong absorption in the UV region with a similar band maximum at λ =370 nm and a clear redshift in the visible‐light region.…”

“…Peaks due to any type of Bi phase could not be observed owing to the small sizes of the NPs. [20,21] The average crystallite sizes of the LDHs,c alculated by the Scherrer equation, were approximately 120 nm forZ nAlLDH and 135 nm for ZnCrLDH, and remained within the same size range after the reconstruction step. Furthermore, XRD analysis showed that calcination at 800 8Cp er- Figure 2B), respectively.…”

“…36‐1451), which revealed that after reconstruction in Bi(NO 3 ) 3 aqueous solution, the LDH structure was not completed restored, although the major peaks were attributed to the LDH structure. Peaks due to any type of Bi phase could not be observed owing to the small sizes of the NPs . The average crystallite sizes of the LDHs, calculated by the Scherrer equation, were approximately 120 nm for ZnAlLDH and 135 nm for ZnCrLDH, and remained within the same size range after the reconstruction step.…”

“…Namely, ZnAlLDH and ZnCrLDH (2 g) were calcined in an oven at 500 °C for 8 h. The resulting calcined powders were added to an aqueous solution of Bi(NO 3 ) 3 (250 mL, 0.1 g, >99.9 %, Sigma–Aldrich) with stirring at a rate of 900 rpm. The mixture was stirred at a rate of 900 rpm at room temperature for 3 h and was subsequently irradiated for 15 min by using a Solar simulator (Model US 800, Unnasol, Germany) . Then, the precipitate was centrifuged and dried at 55 °C, under vacuum.…”

“…During the tests, the stationary temperature of the reactor was kept at 45 °C; the reactor was evacuated several times to remove air and was purged for 20 min with argon flow before the sample was irradiated by using an Unnasol US 800 solar simulator, 180 W, equipped with UV and visible block filters. The evolved gases were analyzed by gas chromatography (GC‐17A Shimadzu) by using a MS‐5A column and a thermal conductivity detector (TCD) …”