Hydrothermal synthesis of single-crystal Cr-doped SrTiO₃ for efficient visible-light responsive photocatalytic hydrogen evolution

Abstract

Visible-light-driven Cr-doped SrTiO 3 nanocubes were successfully synthesized by hydrothermal method in alkaline KOH conditions. X-ray diffraction spectroscopy (XRD), Raman spectra, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to characterize the samples, and the Cr-doped SrTiO 3 possess cubic morphology with about 30-50 nm in size, and single-crystal feature. In addition, the Cr-doped SrTiO 3 extended light-harvesting properties to visible-light region which was testified by UV-vis absorption spectra, and excellent charge transfer and separation efficiency were approved by photo fluorescence spectra (PL), electrochemical impedance spectroscopy (EIS) and photocurrent response measurements. Among the synthesized photocatalysts, SrTiO 3 nanocubes doped with 2% Cr by molar ratio exhibits the highest photocatalytic activity, achieving 11.66 μmol of H 2 evolution during 5 h visiblelight irradiation. This study provides a facile and effective way to enhance the performance of SrTiO 3 -based photocatalysts.

Fabrication of Mn-Doped SrTiO3/Carbon Fiber with Oxygen Vacancy for Enhanced Photocatalytic Hydrogen Evolution

“…SrTiO3 plies observed in Figure 4a are nano-fragments shed from the Mn-SrTiO3@CF sample that was cut into pieces, from which it can be seen that most of the SrTiO3 plies are composed of small particles of 10-20 nm together, and these small nanoparticles have a larger specific surface area, which is conducive to improving the photocatalytic activity. The corresponding interplanar spacing shown in Figure 4c is about 0.279 nm, which shall belong to the (110) crystal face of SrTiO3 (PDF#35-0734) [30]. The doping of a small amount of Mn may change the spacing of the crystal face, which is not significant.…”

Cu2O/SrTi1–xCrxO3 Heterojunction Photocatalyst for the Efficient Degradation of Isopropanol under Visible Light Irradiation

“…30 Compared to that of pure SrTiO 3 , the (110) peak of SrTi 1−x Cr x O 3 shifts slightly to a low value of 2θ, indicative of an expanded lattice mainly because the positive charge of Cr 3+ is lower than that of Ti 4+ and the radius of Cr 3+ (0.62 Å) is slightly larger than that of Ti 4+ (0.61 Å). 25,30 We deduced that Cr 3+ ions do not change the crystal structure of SrTiO 3 but dope into SrTiO 3 . Figure 1b The absorption edge of pure white SrTiO 3 powder is 3.2 eV at ∼390 nm.…”

“…To analyze the microstructure of Cu 2 O/SrTi 1– x Cr x O 3 , we elected 3% Cu 2 O/SrTi 0.99 Cr 0.01 O 3 as the typical sample and present its HRTEM and EDS mapping images in Figure . The HRTEM image shows two intimate grains with lattice fringes of 0.240 and 0.277 nm, which correspond to the (111) lattice plane of Cu 2 O and the SrTi 0.99 Cr 0.01 O 3 (110) plane, respectively. ,, The elemental EDS mapping images in Figure b–g indicate that Ti, Cr, Sr, Cu, and O are uniformly distributed. The HRTEM and elemental mapping images demonstrate that the uniform doping of Cr into the lattice of SrTiO 3 and Cu 2 O forms the heterojunction.…”

Carbonized propagation synthesis of porous CQDs–SrTiO3/graphene and its photocatalytic performance for removal of methylene blue

“…SrTiO 3 and CSG samples showed similar emission peaks in the wavelength range of 400–500 nm, probably due to the presence of defects. 37,38 Fig. 5e shows the up-conversion photoluminescence image of CQDs in CSG-5, which is characteristic of CQDs.…”