TiO2-reduced Graphene Oxide Research Articles

Fuel Cell Electrodes: Enhanced Stability and Electrochemical Performance of Carbon‐Coated Ti3+ Self‐Doped TiO2‐Reduced Graphene Oxide Hollow Nanostructure‐Supported Pt‐Catalyzed Fuel Cell Electrodes (Adv. Mater. Interfaces 21/2017)

Chang Hyun Sung, Ramireddy Boppella, and co-authors design a hollow nanostructured carbon-coated Ti3+ self-doped TiO2-reduced graphene oxide as Pt catalyst support with high electrochemical stability in article number 1700564. The developed electrode offers an excellent overall catalytic activity with an outstanding electrochemical stability under high potential cycling (1.2–1.7V) compared with conventional carbon black support materials that normally induce electrochemical corrosion during fuel cell operation, indicating a potential candidate of catalyst supports for polymer electrolyte membrane fuel cells in automotive applications (e.g. fuel cell electric vehicle).

Enhanced photocatalytic activities of TiO2-reduced graphene oxide nanocomposites controlled by Ti[sbnd]O[sbnd]C interfacial chemical bond

In this study, a hydrothermal-prepared TiO2-RG nanocomposites series exhibited excellent photocatalytic activities, of which the results can be largely influenced by a TiOC interfacial chemical bond between TiO2 nanoparticles and RG nanosheets. A stirring TiO2-RG sample was prepared as contrast analysis using the same wet process except for heating. The characteristics of the composites were tested by X-ray diffraction (XRD), Raman, FT-IR, Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) analysis. The photocatalytic properties were verified by UV–vis diffuse reflectance spectra (DRS) testing as well as degrading Rhodamine B (RhB). Our research results show that the better TiOC interfacial chemical bond was formed, the narrower band gap of the nanocomposite was then obtained. The best hydrothermal synthesizing temperature was found out as 120°C. The TiO2-RG nanocomposite, as inexpensive, nontoxic and highly photo-catalytically active, may let it have a potential use in various photocatalytic applications.

Fabrication of TiO2-Reduced Graphene Oxide Nanorod Composition Spreads Using Combinatorial Hydrothermal Synthesis and Their Photocatalytic and Photoelectrochemical Applications.

This study is the first to employ combinatorial hydrothermal synthesis and facile spin-coating technology to fabricate TiO2-reduced graphene oxide (rGO) nanorod composition spreads. The features of this study are (1) the development of a self-designed spin-coating wedge, (2) the systemic investigation of the structure-property relationship of the system, (3) the high-throughput screening of the optimal ratio from a wide range of compositions for photocatalytic and photoelectrochemical (PEC) applications, and (4) the effective coupling between the density gradient TiO2 nanorod array and the thickness gradient rGO. The formation of rGO in the fabricated TiO2-rGO sample was monitored through Fourier transform infrared spectrometry. Transmission electron microscopy images also suggested that the TiO2 nanorod surfaces were covered with a thin layer of amorphous rGO. The rutile TiO2 plane evolution along the composition variation was verified through X-ray diffraction. 7% TiO2-93% rGO on the nanorod composition spread exhibited the most promising photocatalytic ability; the corresponding photodegradation kinetics, denoted by the photodegradation rate constant (k), was determined to be approximately 12.7 × 10-3 min-1. The excellent performance was attributed to the effective coupling between the TiO2 and rGO, which improved the charge carrier transport, thus inhibiting electron-hole pair recombination. A cycling test implied that 7% TiO2-93% rGO is a reliable photocatalyst. A photoluminescence spectroscopy study also supported the superior photocatalytic ability of the sample, which was attributed to its markedly poorer recombination behavior. In addition, without further treatment, the sample exhibited excellent PEC stability; the photocurrent density was more than three times higher than that exhibited by the density gradient TiO2 nanorods.

Pd catalysts supported on rGO-TiO 2 composites for direct synthesis of H 2 O 2 : Modification of Pd 2+ /Pd 0 ratio and hydrophilic property

Abstract The use of nanostructured composites as catalyst supports is a promising route to prepare catalysts with high selectivity and productivity. In this work, reduced graphene oxide-TiO 2 (rGP- x ) composites with a variation of reduced graphene oxide (rGO) content were synthesized by hydrothermal method. Pd/rGP- x catalysts were prepared in incipient-wetness impregnation method for the direct synthesis of H 2 O 2 from H 2 and O 2 . The morphology and electronic properties of catalysts were investigated by XPS, TEM, and Raman spectroscopy. The ratio of Pd 2 + /Pd 0 and the hydrophobicity of the catalysts were increased with the rising content of rGO. As the amount of rGO in the catalysts varied in the range of 0.025 wt%–2 wt%, the selectivity of H 2 O 2 exhibited a tendency of increasing firstly and then decreasing from 0.1 wt% to 2 wt%. It indicates that good catalytic performance for H 2 O 2 synthesis can be achieved only when appropriate amount of rGO is introduced. The H 2 O 2 selectivity and productivity of Pd/rGP-0.025 both improved remarkably compared with Pd/P25. This enhancement originated from the combined effects of the proper ratio of Pd 2 + /Pd 0 and hydrophobicity of the catalyst.

Non-light-driven reduced graphene oxide anchored TiO2 nanocatalysts with enhanced catalytic oxidation performance

As a single-atom-thick carbon material with high surface and good conductivity, graphene provides an ideal platform for designing composite nanomaterials for high-performance catalytic system. Herein, we obtained a TiO2-reduced graphene oxide nanocomposite (TiO2-RGO) with graphene oxide and tetrabutyl titanate using a facile in situ hydrothermal method. The merit of this method is that the nanocomposites could be produced directly from graphene oxide in the hydrothermal reaction, where the reduction of graphene oxide and the decoration of TiO2 occurred simultaneously. TiO2 nanoparticles anchored on graphene sheets as spacers to keep the neighboring sheets separated. The in situ growth route provides a desirable platform for constructing graphene-supported nanocomposites with improved properties. As one of the major applications of the nanocomposites, we investigate the performance of as-prepared TiO2-RGO as effective non-light-driven catalysts for activating H2O2 in oxidative degradation of the dye. The system was employed in oxidation degradation not only to reach high degradation efficiency but also to avoid any energy consumption. Meanwhile, the proposed catalytic system processes broad-spectrum oxidative degradation activity for different model organic pollutants. Overall, this work could provide new insights into the fabrication of a TiO2-RGO as high performance catalysts and facilitate their application in the environmental protection issues.

Photocatalytic degradation of polypropylene film using TiO2-based nanomaterials under solar irradiation

The aim of this research is the reduction of environmental pollution by degrading polypropylene (PP) film in an eco-friendly way via TiO2-based nanomaterials (NMs) under solar irradiation. PP was mingled with TiO2-based NMs; TiO2 nanoparticles (NPs) and its nanocomposite, (TiO2-reduced Graphene Oxide: TiO2-rGO) individually by a facile solution casting technique to comparatively study its photodegradation before and after 130h of solar irradiation in triplicate manner. The photocatalytic degradation of PP, by TiO2-based NMs, is affirmed by various advanced characterization tools such as XRD, FT-IR, FE-SEM and ToF-SIMS. XRD depicts the phase transformation. FT-IR confirms the appearance of carbonyl group with higher carbonyl index leading to efficient photodegradation of PP by TiO2-rGO nanocomposite as compared to TiO2 NPs. Microstructural investigation by FE-SEM reveals the augmented degradation of PP matrix on the surface of TiO2-rGO nanocomposite through the formation of cavity (diameter: ~500nm) at the interface. The prominent peaks in ToF-SIMS affirm generation of Reactive Oxygen Species (ROS) followed by photodegradation. The mechanism of enhancement of photocatalytic degradation by TiO2-rGO nanocomposite has also been presented in detail. The obtained degraded fragments of PP, thus, are biodegradable and facilitate to reduce the environmental pollution by this eco-friendly route.

Single-step solvothermal synthesis of mesoporous anatase TiO2-reduced graphene oxide nanocomposites for the abatement of organic pollutants

In the present work, we have fabricated a novel mesoporous TiO2–rGO nanocomposite by a facile one-step solvothermal method using titanic sulfate as the TiO2 source. The as-prepared composites were characterized by transmission electron microscopy, X-ray diffraction; UV–Vis diffuse reflectance spectra, X-ray photoelectron spectroscopy and photoluminence spectra. In situ nucleation and anchoring of TiO2 nanoparticles onto a graphene sheet is favorable fpr forming an intimate interfacial contact, and the chemically bonded TiO2–rGO nanocomposites commendably enhanced their photocatalytic activity in the photodegradation of rhodamine B and phenol. The high photocatalytic activity of the as-synthesized nanocomposites are primarily ascribed to the mesoporous structure, efficient charge transportation and separation with enhanced visible light absorption, which come from the appealing nanoarchitecture, for instance, ultra-dispersed and ultra-small TiO2 nanocrystals along with intimate and absolute interfacial contact between the TiO2 nanocrystals and the graphene sheet.

Enhanced performance of dye-sensitized solar cells with layered structure graphitic carbon nitride and reduced graphene oxide modified TiO2 photoanodes

TiO2/reduced graphene oxide (TiO2/rGO) composite has been widely exploited as the photoanode material for high efficient dye-sensitized solar cells (DSSCs). However, the power conversion efficiency (PCE) is limited due to the charge recombination between the rGO and electrolyte. In this paper, we incorporate 5.5wt% layered structure graphitic carbon nitride (g-C3N4) and 0.25wt% rGO into TiO2 nanoparticle (NP) film to form a triple-component TiO2/rGO/g-C3N4 (TGC) photoanode for DSSCs. The TGC photoanode significantly increased the dye absorption and thus to improve the light harvesting efficiency. Furthermore, the electrochemical impedance spectroscopy (EIS) analysis of the DSSCs based on TGC photoanode demonstrates that the incorporation of the rGO and g-C3N4 into TiO2 effectively accelerates the electron transfer and reduces the charge recombination. As a result, the DSSCs based on TGC film show PCE of 5.83%, enhanced by 50.1% compared with that of pure TiO2 photoanodes. This result strongly suggests a facile strategy to improve the photovoltaic performance of DSSCs.

Enhanced photocatalytic activities of low-bandgap TiO2-reduced graphene oxide nanocomposites

In this study, a hydrothermal method was successfully used to prepare a reduced graphene oxide (RG)–titanium dioxide (TiO2) hybrid in 10–20 nm, starting from commercial TiO2 P25 nanoparticles and liquid-exfoliated graphene oxide (GO). Compared to TiO2, an obvious red shift of light absorption (from 3.1 to 2.6 eV) of the as-prepared RG–TiO2 was observed by UV–Vis analysis, and an enhanced photocatalytic degradation of the Rhodamine B (Rh. B) was also observed under Xe lamp exposure test by using the as-prepared RG–TiO2. Multiple characterizations of this RG–TiO2 nanocomposite confirmed that its photocatalytic enhancement could be ascribed to two approaches. Firstly, RG extended the mean free path and photogenerated electrons’ lifetime of TiO2, which minimized electron–hole pairs’ recombination. Secondly, RG expanded the light absorption spectrum of TiO2 from UV range to UV and visible light range. The explication of these improvements was concluded as the energy gap changing and a likelihood of up-conversion photoluminescence mechanism (UCPL). Due to the low-cost, nonpoisonous and excellent photocatalytic properties of RG–TiO2, this material can be applied well in sewage treatment and other related fields.

One-step solvothermal synthesis of TiO2-reduced graphene oxide nanocomposites with enhanced visible light photoreduction of Cr(VI)

Hexavalent chromium, Cr(VI), is a mutagenic and carcinogenic heavy metal environmental pollutant. Photoreduction is one of the remediation methods of the hexavalent chromium Cr(VI), which necessitates design of an efficient catalyst for visible light performance. Here, we report a one-step solvothermal synthesis of TiO2-reduced graphene oxide (TiO2-xRGO) composite catalysts using a mild reducing agent, dimethylformamide (DMF). Nanoscale TiO2 particles in the size range of 4–9 nm were formed on the reduced graphene sheets. The formation of the composite catalysts was accompanied by the appearance of a large fluorescence quenching, which indicates an efficient separation of photogenerated electrons and holes. The composites displayed excellent photoreduction of Cr(VI) in the visible light, which was found to be a function of the weight percentage of RGO in the composite. At the optimum composition of TiO2-xRGO, a maximum removal rate of 96% was recorded, which was higher than that of the pristine TiO2, which showed no appreciable catalytic activity under the same condition. The performance degraded with increasing RGO content in the composite, which can be attributed to the higher electron-hole recombination on the RGO surface. The Cr(VI) photoreduction also exhibited a pH dependence. The highest removal rate was observed in the acidic medium.

Reduced graphene oxide embedded titanium dioxide nanocomposite as novel photoanode material in natural dye-sensitized solar cells

Dye-sensitized solar cells were fabricated using the natural dye anthocyanin extracted from Nerium oleander, Ixora coccinea and Erythrina variegata flowers with sol–gel routed TiO2-reduced graphene oxide nanocomposite photoanode. X-ray diffraction analysis of TiO2-reduced graphene oxide nanocomposites proved the anatase phase titania. Scanning electron microscope analysis confirmed the incorporation of reduced graphene oxide in TiO2 matrix. Transmission electron microscopic analysis established the dispersion of reduced graphene oxide in TiO2 network. The influence of reduced graphene oxide on the band gap and life-time of electron–hole pair in TiO2-reduced graphene oxide nanocomposites was observed from ultra violet–visible and photoluminescence spectra respectively. Fourier transform infra-red analysis confirmed the expected interaction between TiO2 and reduced graphene oxide. An increase in electrical conductivity was observed in TiO2-redcued graphene oxide nanocomposites than the pristine TiO2. The optimized TiO2-redcued graphene oxide nanocomposite was used as an anode material in the construction of dye-sensitized solar cells and the performance was studied by photocurrent–voltage characteristics and electrochemical impedance spectroscopy. The solar cells with TiO2-redcued graphene oxide nanocomposite photo anode exhibited enhanced efficiency of 0.47–0.57%.

Synthesis and photocatalytic performance of reduced graphene oxide-TiO2 nanocomposites for orange II degradation under UV light irradiation.

To enhance the photocatalytic activity of TiO2, reduced graphene oxide-TiO2 (RGO-TiO2) composites with sandwich-like structure were synthesized using a simple solvothermal method. The morphology, crystalline information, and structural property of the photocatalyst were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transmission infrared spectroscopy. The photocatalytic performances of the RGO-TiO2 composites were evaluated by the degradation of orange II (AO7) in water under UV light irradiation. The results showed that the RGO-TiO2 composites exhibited much higher photocatalytic activity than TiO2 and that the removal efficiency of AO7 could reach above 95% only after 20min of UV light irradiation under the optimum condition. The improved photocatalytic activity might be attributed to the improved charge transfer and significant separation of the photoinduced electrons and holes in the presence of a two-dimensional graphene network. The results of recycling experiments show that RGO-TiO2 composites have a high photostability, which is expected in the practical application. Radical trapping experiments indicated that ·OH plays a crucial role in the process of AO7 degradation.

A detailed investigation on the performance of dye-sensitized solar cells based on reduced graphene oxide-doped TiO2 photoanode

The sintered TiO2 nanofilms were immersed in the aqueous solution of graphite oxide and then were thermally reduced to reduced graphene oxide (RGO), resulting in RGO-doped TiO2 photoanodes employed in the dye-sensitized solar cells (DSSCs). This preparation method for the reduced graphene oxide–TiO2 (RGO–TiO2) photoanode could avoid the loss of RGO during the sintering process. The presence of RGO in the photoanodes was confirmed using Raman analysis, scanning electron microscopy, transmission electron microscopy, and energy-dispersive spectrometer. The amount of RGO in photoanode was obtained by thermo-gravimetric analysis. Other techniques such as X-ray diffraction, Brunauer–Emmett–Teller, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the composite materials of RGO–TiO2. The J–V measurement of RGO–TiO2-based DSSCs showed that the best photoelectric conversion efficiency (η) of 6.85% is 11.7% higher than that of the pure TiO2 (P25–TiO2)-based DSSCs. It was shown that RGO in the photoanode could facilitate the phase transition in TiO2 crystals (from anatase to rutile) resulting in the mixed crystals in the photoanodes. The existence of RGO and mixed-crystal structure of TiO2 changed the electronic transmission pathway, reduced the recombination rate of electron–hole pairs, and thus improved the η of DSSCs.

Structural and magnetic properties of reduced graphene oxide-TiO2 nanoflower composite

We have focused on the structural and magnetic properties of hazardous acid free synthesis of anatase titanium dioxide (TiO2) phase nanoflower and reduced graphene oxide-TiO2 (rGO-TiO2) nanocomposite using hydrothermal process. Because, strong acids free synthesis is environmental friendly and reduce overall cost of synthesized samples. In the synthesis of rGO-TiO2, synthesized TiO2 nanoflower and graphene oxide (GO) were used as reagents. The resulting materials have analyzed using different techniques such as, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Fourier Transformation Infrared spectrophotometer for confirmation of flower like morphology, crystalline phase and chemical composition. Moreover, VSM analysis has revealed the ferromagnetism induced in the rGO-TiO2 composite at room temperature. The values of saturation magnetization were found to be 0.002 and ~ 0.243±0.04emu/g for TiO2 nanoflower and rGO-TiO2 nanocomposite, respectively. In comparison of pure TiO2, rGO-TiO2 exhibited larger magnetization at room temperature. This is because presences of various edge and site defects such as topological and point defects like vacancies, which create localized unpaired spins in reduced graphene oxide (rGO), induce the ferromagnetism behavior in rGO-TiO2 nanocomposite.

Comparison study on photocatalytic oxidation of pharmaceuticals by TiO2-Fe and TiO2-reduced graphene oxide nanocomposites immobilized on optical fibers

Incorporating reduced graphene oxide (rGO) or Fe3+ ions in TiO2 photocatalyst could enhance photocatalytic degradation of organic contaminants in aqueous solutions. This study characterized the photocatalytic activities of TiO2-Fe and TiO2-rGO nanocomposites immobilized on optical fibers synthesized by polymer assisted hydrothermal deposition method. The photocatalysts presented a mixture phase of anatase and rutile in the TiO2-rGO and TiO2-Fe nanocomposites. Doping Fe into TiO2 particles (2.40eV) could reduce more band gap energy than incorporating rGO (2.85eV), thereby enhancing utilization efficiency of visible light. Incorporating Fe and rGO in TiO2 decreased significantly the intensity of TiO2 photoluminescence signals and enhanced the separation rate of photo-induced charge carriers. Photocatalytic performance of the synthesized nanocomposites was measured by the degradation of three pharmaceuticals under UV and visible light irradiation, including carbamazepine, ibuprofen, and sulfamethoxazole. TiO2-rGO exhibited higher photocatalytic activity for the degradation of pharmaceuticals under UV irradiation, while TiO2-Fe demonstrated more suitable for visible light oxidation. The results suggested that the enhanced photocatalytic performance of TiO2-rGO could be attributed to reduced recombination rate of photoexcited electrons-hole pairs, but for TiO2-Fe nanocomposite, narrower band gap would contribute to increased photocatalytic activity.

One-pot route for uniform anchoring of TiO2 nanoparticles on reduced graphene oxides and their anode performance for lithium-ion batteries

TiO2-reduced graphene oxide (RGO) hybrids were prepared using one-pot, simultaneous reduction of graphene oxide (GO) to RGO and anchoring of TiO2 nanoparticles on the surface of RGO in supercritical isopropanol. Numerous anchor sites facilitating heterogeneous nucleation of TiO2 particles on GO, and extremely fast nucleation due to the supercritical alcohol led ultrafine, well-dispersed anatase TiO2 nanoparticles to anchor to the RGO sheets in a single step. The unique synthetic approach developed herein was very effective for preventing restacking of graphene sheets during reduction, and for tightly anchoring TiO2 nanoparticles to the RGO surface. When the TiO2-RGO with a TiO2 loading of 48wt% tested as an anode in lithium-ion battery, it exhibited excellent electrochemical performance with a high reversible capacity of 229mAhg−1 at 50mAg−1 after 50 cycles and a high-rate performance of 115mAhg−1 at 1Ag−1, and 95% of the initial capacity was retained even after 1000 cycles (at rate of 1Ag−1).

Photocatalytic CO2 reduction using water as an electron donor by a powdered Z-scheme system consisting of metal sulfide and an RGO-TiO2 composite.

CuGaS2, (AgInS2)x-(ZnS)2-2x, Ag2ZnGeS4, Ni- or Pb-doped ZnS, (ZnS)0.9-(CuCl)0.1, and ZnGa0.5In1.5S4 showed activities for CO2 reduction to form CO and/or HCOOH in an aqueous solution containing K2SO3 and Na2S as electron donors under visible light irradiation. Among them, CuGaS2 and Ni-doped ZnS photocatalysts showed relatively high activities for CO and HCOOH formation, respectively. CuGaS2 was applied in a powdered Z-scheme system combining with reduced graphene oxide (RGO)-incorporated TiO2 as an O2-evolving photocatalyst. The powdered Z-scheme system produced CO from CO2 in addition to H2 and O2 due to water splitting. Oxygen evolution with an almost stoichiometric amount indicates that water was consumed as an electron donor in the Z-schematic CO2 reduction. Thus, we successfully demonstrated CO2 reduction of artificial photosynthesis using a simple Z-scheme system in which two kinds of photocatalyst powders (CuGaS2 and an RGO-TiO2 composite) were only dispersed in water under 1 atm of CO2.

A gigantically increased ratio of electrical to thermal conductivity and synergistically enhanced thermoelectric properties in interface-controlled TiO2-RGO nanocomposites.

We report synergistically enhanced thermoelectric properties through the independently controlled charge and thermal transport properties in a TiO2-reduced graphene oxide (RGO) nanocomposite. By the consolidation of TiO2-RGO hybrid powder using spark plasma sintering, we prepared an interface-controlled TiO2-RGO nanocomposite where its grain boundaries are covered with the RGO network. Both the enhancement in electrical conductivity and the reduction in thermal conductivity were simultaneously achieved thanks to the beneficial effects of the RGO network, and detailed mechanisms are discussed. This led to the gigantic increase in the ratio of electrical to thermal conductivity by six orders of magnitude and also the synergistic enhancement in the thermoelectric figure of merit by two orders. Our results present a strategy for the realization of 'phonon-glass electron-crystals' through interface control using graphene in graphene hybrid thermoelectric materials.

Reduced Graphene Oxide-TiO<sub>2</sub> Nanocomposite Facilitated Visible Light Photodegradation of Gaseous Toluene

The photocatalytic degradation of gaseous toluene was investigated on TiO2 nanoparticles coated on reduced graphene oxide. Reduced graphene oxide-TiO2 composite (RGO-TiO2) was synthesized via two step processes. The prepared RGO-TiO2 composite was characterized using SEM, XRD, and UV-visible spectra. A significant increase in light absorption to visible light was observed by RGO-TiO2 compared with that of pure TiO2 nano particles. The photocatalytic degradation efficiency of the RGO-TiO2 composite was much higher than that of the P25 TiO2, 95% and 40% respectively. In our investigated conditions, the initial concentration, flow rate and relative humidity had significant influences on the photocatalytic degradation of gaseous toluene. The most efficiency was recorded at the 0.3 ppm concentration, 1L/min flow rate and 30% relative humidity. We believe that this TiO2 based composite material can be effectively used as a highly active and stable photocatalyst to remove various indoor air pollutants especially gaseous toluene. The photocatalytic degradation efficiencies of toluene increased slowly below 20% relative humidity and then decreased as the relative humidity increased further. The main reason of enhanced photocatalytic property might be the strong electron transfer ability, and the increased adsorption capacity of RGO sheets in the composites as well as the retarded charge recombination rate contributed by the energy level of the two materials. We believe that this TiO2 based composite material can be effectively used as a highly active and stable photocatalyst to remove various gaseous pollutants.

Graphene oxide-TiO2 and reduced graphene oxide-TiO2 nanocomposites: Insight in charge-carrier lifetime measurements

A hybrid nanocomposites containing nanocrystalline TiO2 and graphene related materials (graphene oxide and reduced graphene oxide) were successfully prepared elevated pressure using hydrothermal method. The structural and textural properties as well as the presence of different carbonaceous structures on the surface of obtained nanocomposites have been characterized by means of XRD, FTIR/DRS and Raman spectroscopy. FTIR/DRS analysis allowed to find characteristic peaks of graphene oxide: epoxy stretching at 1229cm−1 and alkoxy stretching vibration at 1059cm−1. In the spectrum of nanocomposites containing rGO, all the bands decreased or even disappear. It can be indicated that GO was successfully reduced to rGO. SEM studies showed difference between graphene oxide (aggregated, crumpled, non-transparent) and reduced graphene oxide (thin and transparent) flakes. The Time Resolved Microwave Conductivity analysis have been utilized to investigate the excess of charge-carrier lifetimes in TiO2-graphene oxide and TiO2-reduced graphene oxide hybrid nanocomposites. It was generally concluded that modification of starting TiO2 with carbonaceous precursors leads to the slight increase of intensity of the TRMC signals, indicating that more electrons are induced in the conduction band of hybrid nanocomposites. It is also worth mentioning that the decay of studied signals of modified powders depends on added carbon precursor, indicating that the type of deposited species may affect the slight or significant suppression of recombination or charge-carriers trapping.