Mono- and bimetallic nanoparticles decorated KTaO3 photocatalysts with improved Vis and UV–Vis light activity

• Published in: Applied surface science 2018-05, Vol.441, p.993-1011
• Main Authors: Krukowska, Anna, Trykowski, Grzegorz, Winiarski, Michal Jerzy, Klimczuk, Tomasz, Lisowski, Wojciech, Mikolajczyk, Alicja, Pinto, Henry P., Zaleska-Medynska, Adriana
• Format: Article
• Language: English
• Subjects: Mono- and bimetallic nanoparticles; Noble metal photodeposition; Perovskite KTaO3; Pollutant degradation/H2 generation; Vis/UV–Vis photocatalytic activity
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.02.077

[Display omitted] •Mono- and bimetallic nanoparticles modified KTaO3 surface by photodeposition method.•Simultaneous or subsequent photoreduction of BNPs on KTaO3 surface.•Perovskite phase formation in KTaO3 crystalline structure.•Improved Vis light activity of MNPs/BNPs-KTaO3 in phenol and toluene degradation.•Enhanced photocatalytic H2 generation from formic acid over MNPs/BNPs-KTaO3. Novel mono- and bimetallic nanoparticles (MNPs and BNPs) decorated surface of perovskite-type KTaO3 photocatalysts were successfully synthesized by hydrothermal reaction of KTaO3 followed by photodeposition of MNPs/BNPs. The effect of noble metal type (MNPs = Au, Ag, Pt, Pd, Rh, Ru or BNPs = Au/Pt, Ag/Pd, Rh/Ru), amount of metal precursor (0.5, 1.0, 1.5 or 2.0 wt%) as well as photoreduction method (simultaneous (both) or subsequent (seq) deposition of two metals) on the physicochemical and photocatalytic properties of MNPs- and BNPs-KTaO3 have been investigated. All as-prepared photocatalysts were subsequently characterized by UV–Vis diffuse reflectance spectroscopy (DRS), Brunauer-Emmett-Teller (BET) specific surface area and pore size distribution measurement, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (PXRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) emission spectroscopy. The crystal structure was performed using visualization for electronic and structural analysis (VESTA). The photocatalytic activity under Vis light irradiation was estimated in phenol degradation in aqueous phase and toluene removal in gas phase, while under UV–Vis light irradiation was measured amount of H2 generation from formic acid solution. The absorption properties of O2 and H2O molecules on KTaO3(1 0 0) surface supported by Au or Au/Pt NPs was also investigated using density-functional theory (DFT). The experimental results show that, both MNPs-KTaO3 and BNPs-KTaO3 exhibit greatly enhanced pollutant decomposition efficiency under Vis light irradiation and highly improved H2 production under UV–Vis light irradiation compared with pristine KTaO3. MNPs deposition on KTaO3 surface effects by disperse metal particle size ranging from 11 nm (Ru NPs) to 112 nm (Au NPs). Simultaneous addition of Au/Pt precursors results in formation of agglomerated larger metal nanoparticles (50–100 nm) on KTaO3 surface than subsequent deposition of Au/Pt with composition of c