Band-gap tuning and nonlinear optical characterization of Ag:TiO2 nanocomposites

Abstract

Silver/titanium dioxide nanoparticles with varied concentration of silver have been synthesized by a simple laser light induced chemical reaction, where bulk titanium dioxide powder is used as the starting material. The particle size, morphology, crystal structure, and optical properties were characterized by transmission electron microscopy, x-ray diffraction, UV-Vis absorption spectroscopy, fluorescence spectroscopy, and Fourier transform infrared spectroscopy. The x-ray diffraction pattern revealed that the TiO2 nanoparticles obtained are in pure rutile phase. The important observation from transmission electron microscopic images is that the Ag particles are distributed over the surface of titanium dioxide nanoparticles. The band gap of the TiO2 nanoparticles was tuned between 1.75 and 2.75 eV by varying Ag concentration. The nonlinear optical absorption and optical limiting performance of Ag:TiO2 nanocomposites were investigated by open aperture z-scan using nanosecond Nd:YAG laser pulses operating at 532 nm. The best optical limiting threshold obtained was 113MW/cm2.

Photocatalytic Performance of Ag and CuBiS2 Nanoparticle-Coated SiO2@TiO2 Composite Sphere under Visible and Ultraviolet Light Irradiation for Azo Dye Degradation with the Assistance of Numerous Nano p–n Diodes

“…However, after Ag nanoparticles were coated on SiO 2 /TiO 2 , the composite sphere has visible light optical band gap of 2.8 eV, as supported by the SiO 2 /TiO 2 and SiO 2 /TiO 2 /Ag data in Figure 5. The tunable visible light band gap of TiO 2 achieved by varying the Ag content in TiO 2 /Ag composite also has been reported by Hari et al 47 The SiO 2 / TiO 2 /CuBiS 2 /Ag composite sphere combined the UV absorbance of TiO 2 , the visible light absorbance of CuBiS 2 , and the surface plasmonic resonance absorbance of Ag nanoparticles. The optical band gap of the SiO 2 /TiO 2 / CuBiS 2 /Ag composite sphere was 2.9 eV as calculated from its DRS data.…”

Bandgap Tuning by Using a Lattice Distortion Induced by Two Symmetries That Coexist in a Quantum Dot

“…Metallic Ag nanocrystallites on a semiconductor such as TiO 2 can also reduce the optical bandgap and enhance the absorption coefficient of the semiconductor owing to the local‐field enhancement by the surface plasmon resonance of silver nanoparticles . According to our experimental results, however, there is little variation in the optical properties between the Ag 2 S QDs (deposited at 25 °C by the SILAR process) and the sequentially deposited Ag+Ag 2 S mixed QDs on TiO 2 particles (Figure S2).…”

TiO2–multi-walled carbon nanotube nanocomposites: hydrothermal synthesis and temporally-dependent optical properties

“…TiO 2 has been used previously to prepare MWCNT/TiO 2 nanohybrids for photocatalytic and solar cell applications, 17,18 but the use of such nanohybrids to fabricate optoelectronic devices with superior OL performance has not been reported, although the nonlinear optical properties of a range of nanoscale composite materials containing TiO 2 have been explored. [19][20][21][22][23][24] Previous studies of MWCNT/TiO 2 materials have highlighted the interesting properties of nanocomposites obtained by a variety of approaches. 21,25 Herein, and inspired by the ndings above, we have explored combining TiO 2 nanoparticles with MWCNTs by a simple hydrothermal treatment of tetrabutyl titanate and MWCNTs in EtOH-H 2 O mixtures.…”

“…[19][20][21][22][23][24] Previous studies of MWCNT/TiO 2 materials have highlighted the interesting properties of nanocomposites obtained by a variety of approaches. 21,25 Herein, and inspired by the ndings above, we have explored combining TiO 2 nanoparticles with MWCNTs by a simple hydrothermal treatment of tetrabutyl titanate and MWCNTs in EtOH-H 2 O mixtures. The composition and structure of these TiO 2 /MWCNT nanocomposites have been elucidated by Fourier-transform infrared, Raman, and X-ray photoelectron spectroscopies, X-ray powder diffraction, and transmission electron microscopy.…”