Effects of Different TiO2 Particle Sizes on the Microstructure and Optical Limiting Properties of TiO2/Reduced Graphene Oxide Nanocomposites

Abstract

TiO2/reduced graphene oxide (rGO) nanocomposites with two different TiO2 particle sizes were synthesized by a facile hydrothermal method using two different source materials of Ti: tetrabutyl titanate (TBT) and commercial TiO2 powder (P25). For respective series with the same source materials, we investigated additions that optimized the nonlinear optical properties (NLO) and optical limiting (OL) performances, and we explored the relationships between structural diversity and performance. Several characterization techniques, including X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and diffuse reflectance ultraviolet-visible spectroscopy (UV-Vis) were conducted to confirm the microstructures and chemical states of as-prepared materials. This indicated the existence of the Ti–O–C bond between rGO sheets and TiO2 particles and the reduction from precursor graphene oxide (GO) to rGO. The results of UV-Vis spectra revealed that the TiO2/rGO nanocomposites showed smaller band gaps than bare TiO2. A nanosecond open-aperture Z-scan technique at 1064 nm was applied to investigate NLO and OL properties. TiO2/rGO nanocomposites exhibited enhanced NLO and OL performances, arising from synergistic effects, compared to individual components. The TBT series samples performed better than the P25 series, presumably relevant to dimensional effects.

Donor-Acceptor Type Reduced Graphene-Oxide and a Tin-Selenide Nanohybrid With Broad and Ultrafast Optical Limiting Properties

“…The range of conventional OL materials is diverse, ranging from porphyrins, phthalocyanines [23], and mixed metal-complexes [24] to carbon-based nanomaterials such as fullerenes and carbon nanotubes [25]. Recently, the OL properties of emerging 2D materials were studied in detail for MoS 2 quantum dots [26], black phosphorus [27], and TiO 2 /RGO [28]. Carbon-based materials are a typically used representative 2D-system for optical limiters.…”

Preparation and Characterization of Nanocrystalline TiO2 on Microsericite for High-Efficiency Photo-Energy Conversion of Methanol to Hydrogen

“…Accordingly, the band gaps of the T, 10A-T, TS, and 10A-TS photocatalysts were 2.96 eV, 2.97 eV, 3.03 eV, and 3.10 eV, respectively. Nano-sized crystal cause the band gap to become more extensive due to the quantum effect [33] or scattering effect [34]. As the crystalline sizes decreased, the band gaps became larger.…”

Graphene Oxide-Based Silico-Phosphate Composite Films for Optical Limiting of Ultrashort Near-Infrared Laser Pulses

“…Graphene has been identified by many industry sectors as a key material that will drive future product development in flexible electronics, smart textiles, biosensors, drug delivery, water filtration, supercapacitors and more, as stated by the Graphene Report 2020 [ 4 ]. Lately, graphene has shown great potential as an ideal material for modern photonic, optoelectronic and electronic devices due to its ultrafast carrier relaxation dynamics and ultra-broadband NLO response as a consequence of its extended π-conjugate system and the linear dispersion relation holding for its electronic band structure [ 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ].…”