Monodisperse TiO2 Research Articles

Preparation of TiO2/Ni‐NG Mesoporous Microspheres and Photocatalytic Hydrogen Evolution Properties

AbstractThe regulation of surface active sites and structures is a key factor affecting the performance of photocatalysts. In order to prepare monodisperse anatase TiO2 mesoporous microspheres with higher specific surface area, smaller pore size and particle size, a dual‐surfactant orientation assembly method was selected. Graphene (NG) was selected as a cocatalyst to compound with mesoporous TiO2 and nickel doping was performed on the cocatalyst to improve the photocatalytic hydrogen production activity of the semiconductor photocatalyst. Through proper regulation and rational design, the semiconductor photocatalyst with desired properties was prepared. SEM characterization of mesoporous titanium dioxide (TiO2/Ni‐NG) with graphene cocatalyst proved that TiO2 nanospheres have good monodispersion, and TiO2 nanospheres are well supported on graphene cocatalyst. The composite material belonged to mesoporous group with the pore size being mainly distributed between 10–20 nm. The loading of graphene and Ni‐NG cocatalyst increased the absorption band edge by 9 nm and 38 nm, respectively, and the band gap decreased by 0.07 eV and 0.16 eV, respectively. The selection of graphene as cocatalyst improved the hydrogen production activity of photocatalyst and nickel doping was very effective in the modification of graphene. For reaction time of 2.5 h, the H2 production of TiO2/Ni‐NG material reached 1.767 mmol/g which was 7.27 times that of TiO2/NG composite material.

Step-scheme perylenediimide supramolecular nanosheet and TiO2 nanoparticle composites for boosted water splitting performance

Adjusting the band gap of organic-inorganic composites by chemical bonding can effectively construct Step-scheme (S-scheme) heterojunctions, featuring properties of fast photogenerated charge migration and excellent photocatalytic performance. In this work, a novel perylene-3, 4, 9, 10-tetracarboxylicdiimide (PDI)-titanium dioxide (TiO2) heterojunction is elaborately synthesized through simple solvent compounding method. The monodispersed spherical TiO2 nanoparticles was prepared with the capping agents of oleylamine and oleic acid, and suffered by a ligand exchange process with nitrosonium tetrafluoroborate (NOBF4) to remove oleylamine and oleic acid. The NOBF4 ligands were further replaced by PDI super molecular nanosheets to obtain two dimensional (2D)-zero dimensional (0D) PDI-TiO2 composites. TiO2 nanoparticles are evenly anchored on the surface of PDI nanosheets with intimate contact. The PDI-TiO2 composites has emerged considerably superior activity in hydrogen evolution. The highest hydrogen evolution rate for PDI-TiO2composites with the PDI weight percentage of 2.4% was 9766 μmol h−1 g−1 under solar light irradiation, which is 2.56 times of TiO2-NOBF4 catalyst. Moreover, PDI-TiO2 composites possess stoichiometric overall water splitting performance with H2 and O2 release rates of 238.20 and 114.18 μmol h−1 g−1. The superior photocatalytic performance of PDI-TiO2 composites can be attributed to the dramatic increase in visible and NIR light absorption caused by π-π stacking structure of PDI, the prevented charge recombination by the S-scheme heterojunction, and the enhanced oxygen evolution by the stronger oxidation capability of PDI. PDI supramolecular nanosheets may work as a novel functional support for many types of semiconductor nanomaterials as graphene, which will display a wide range of application prospects in the energy and environmental fields.

Al/TiO2 composite as a photocatalyst for the degradation of organic pollutants.

TiO2 is a catalyst that can effectively degrade organic pollutants with the following advantages, low cost, simplicity, and pollution-free nature. In recent years, the non-noble plasmonic metal Al has effectively improved the photocatalytic performance of TiO2. However, the current reports are limited to the photocatalytic performance of Al/TiO2 on the substrate, which requires expensive large-scale vacuum equipment. In this study, monodispersed Al particles were proposed to enhance the photocatalysis of TiO2. The localized surface plasmon resonance (LSPR) effect of Al is proven by finite difference time domain method (FDTF) simulation. Then, Al/TiO2 composites were prepared by combining monodispersed Al and TiO2. The influence of ligand (glutathione (GSH), glutamic acid (GAG), or 3-mercaptopropane acid (MPA)), Al size (40 to 300 nm), and the ratio of Al to TiO2 (0.5:1 to 10:1) on the photocatalytic degradation of methylene blue (MB) by Al/TiO2 were discussed. The obtained results showed that the Al/TiO2 composite which were prepared with 200 nm Al particles, GSH as the ligand bridge, and an Al:TiO2 ratio of 1:1 had the best MB degradation effect. It can degrade 97.7% of 10 mg/L MB in 100 min. The reaction rate of the Al/TiO2 composite with the optimal photocatalytic performance is k=3.36×10-2 min-1, which is 10 times that of P25 TiO2. In addition, Al/TiO2 has a good photocatalytic effect on rhodamine B (RhB) and crystal violet (CV). Therefore, Al/TiO2 composites with the advantage of high efficiency are a type of potential photocatalytic material that can be used for the photocatalytic treatment of organic pollutants in water.

Synthesis and Characterization of Anatase TiO2 Nanorods: Insights from Nanorods’ Formation and Self-Assembly

Highly crystalline, organic-solvent-dispersible titanium dioxide (TiO2) nanorods (NRs) present promising chemicophysical properties in many diverse applications. In this paper, based on a modified procedure from literature, TiO2 NRs were synthesized via a ligand-assisted nonhydrolytic sol-gel route using oleic acid as the solvent, reagent, and ligand and titanium (IV) isopropoxide as the titanium precursor. This procedure produced monodisperse TiO2 NRs, as well as some semi-spherical titania nanocrystals (NCs) that could be removed by size-selective precipitation. X-ray diffraction and selected area electron diffraction results showed that the nanorods were anatase, while the semipheres also contained the TiO2(B) phase. By taking samples during the particle growth, it was found that the average length of the initially grown NRs decreased during the synthesis. Possible reasons for this unusual growth path, partially based on high-resolution transmission electron microscopy (HRTEM) observations during the growth, were discussed. The dispersion of anatase TiO2 nanorods was capable of spontaneous formation of lyotropic liquid crystals on the TEM grid and in bulk. Considering high colloidal stability together with the large optical birefringence displayed by these high refractive index liquid crystalline domains, we believe these TiO2 NRs dispersions are promising candidates for application in transparent and switchable optics.

Facile Construction of Tio <sub>2</sub>Co <sub>0.6</sub>Cu <sub>0.25</sub>Zn <sub>0.15</sub>Fe <sub>2</sub>O <sub>4</sub> Nanocomposite with Highly Improved Sunlight Photocatalytic and Stability Performance

A magnetic nanocomposite Tio2/Co0.6Cu0.25Zn0.15Fe2O4, was synthesized via a co-precipitation followed by Sol-Gel method. Ferrite magnetic nanoparticles (NPs) Co0.6Cu0.25Zn0.15Fe2O4 are obtained by co-precipitation method using (cetyltrimethylammonium bromide, CTAB) as surfactant. Co0.6Cu0.25Zn0.15Fe2O4 (NPs) are mixed with the titanium precursor during sol-gel process, which promotes their direct jonction with TiO2 primary particles. The prepared materials were characterized, by XRD, FTIR, Raman Spectra, SEM-EDX, HR-TEM, UV-vis, DRS Spectra, and PL Spectra. It was demonstrated that the nanocomposite is composed of mixed-phase crystals of TiO2 anatase and cubic spinel ferrite Co0.6Cu0.25Zn0.15Fe2O4 with anatase as dominant phase. SEM and TEM images show monodisperse, spherical and aggregated TiO2 microspheres. The integration of Co0.6Cu0.25Zn0.15Fe2O4 (NPs) causes a small change in the aggregation of TiO2 microspheres. The integration of Co0.6Cu0.25Zn0.15Fe2O4 with TiO2 leads to non-uniform distribution of spherical particles. The direct bandgap of Co0.6Cu0.25Zn0.15Fe2O4 nanoparticles (1.34eV) and TiO2/Co0.6Cu0.25Zn0.15Fe2O4 nanocomposite (2.78eV) demonstrate their ability as sunlight photocatalysts. Importantly, the Co0.6Cu0.25Zn0.15Fe2O4 (NPs) demonstrated significantly enhanced photocatalytic degradation of Congo-Red (CR) and paracetamol compared to that from its individual counterparts such as TiO2 and P25 Degussa.

Preparation of TiO2 Nanoparticle Aggregates and Capsules by the ‘Two-Emulsion Method’

TiO2-based materials are of great practical interest in several technological areas. Both the size and the morphology of the TiO2 particles are of critical importance for their applications. The current study explores the effect of several factors on the outcome of the TiO2 particle synthesis via the so-called ‘two-emulsion method’. In this technique, two water-in-oil emulsions—each of them containing different reactant in the dispersed water drops—are mixed under well controlled conditions. Upon such mixing, partial coalescence of the water drops from the two emulsions leads to mixing of the drop content, with chemical reaction occurring within the drops, and to synthesis of Ti(OH)4 particles. Afterwards, the latter are transformed by emulsion heating into TiO2 particles and aggregates of predominantly anatase structure. Our results show that—depending on the precursor and surfactant concentrations, oil viscosity, emulsification time, and mixing speed—the obtained nanoparticles could aggregate either on the drop surface, forming capsules with a very smooth surface, or inside the water droplets, thus leading to hierarchically structured aggregates of micrometer size. The spherical smooth capsules are constructed of very small monodisperse TiO2 nanoparticles with size below 5 nm. The hierarchical bulk aggregates, on the other hand, are formed from bigger primary particles of sub-micrometer size. The obtained results show that one can obtain various TiO2 structures by controlling the conditions during the emulsion preparation and mixing

Engineering of mono-dispersed mesoporous TiO2 over 1-D nanorods for water purification under visible light irradiation.

Herein we synthesized a novel structure of mesoporous TiO2 decorated on 1D ZnO nanorods for environmental remediation. The effect of mesoporous TiO2 over 1D nanorods were investigated. The phase transitions of nanocomposite were confirmed by powder diffraction analysis. The morphological investigation of synthesized TiO2/ZnO catalyst revealed that the TiO2 are in porous in nature which covered the surface of 1D nanorods. The size of mesoporous TiO2 nanoparticles was about 10-15 nm. The chemical composition and elemental mapping results clearly evident that the presence of ZnO and TiO2 is distributed uniformly on ZnO nanorods. TiO2/ZnO nanocomposite shows enhanced activity which degrades in 14 min under visible light irradiation. TiO2/ZnO catalyst with 5 wt % exhibited the high photocatalytic activity (0.1882 min-1). It is proposed that a synergistic interaction between ZnO and TiO2 leads to a charge separation which leads to the enhanced activity.

The potentials of TiO2 nanocatalyst on HMX thermolysis

Even though HMX is one of the most powerful highly explosive materials; HMX-based propellants demonstrated complexity of burning rate control as well as high pressure exponent (n). In addition, HMX is insensitive to common catalyst. TiO2 can offer novel catalyzing ability for HMX. Highly-crystalline, mono-dispersed TiO2 NPs of 5.0 nm particle size with proper surface area (26.87 ± 0. 36 m2/g) were fabricated using hydrothermal processing. TiO2 NPs were re-dispersed in organic solvent and effectively-integrated into HMX via co-precipitation technique; the impact of TiO2 NPs on HMX thermal behavior was investigated using DSC and TGA. TiO2 NPs exposed superior catalytic performance; the endothermic phase change of HMX at 187 °C was decreased by 43.3%. The main exothermic decomposition peak was decreased by 10 °C with enhanced total heat release by 46.7%. The catalytic performance of TiO2 NPs could be ascribed to the release of active surface ȮH radicals that could induce HMX decomposition via hydrogen abstraction. Furthermore, TiO2 NPs could adsorb evolved NO2 on its surface with surge in total heat release in condensed phase.

Three-dimensional monodispersed TiO2 microsphere network formed by a sub-zero sol-gel method

The monodispersed TiO2 microspheres were synthesized by a sub-zero sol-gel method followed by calcination. The precursor was prepared by hydrolysis of tetrabutyl titanate at −10 °C. The influence of the post-calcination temperature on the particle morphology and the crystal properties was investigated. The microspheres have possessed excellent thermal stability without anatase-to-rutile transformation even at 900 °C, probably due to the stabilized microstructure of a honeycomb mesh. The photocatalytic activity for oxidative decomposition of methyl orange depends on the morphology and the crystalline properties, being the highest for highly crystallized and mesoporous sample, prepared at 700 °C calcination.

Facile synthesis and growth mechanism of mesoporous anatase titanium dioxide nanoparticles via sol-gel method

An investigation on the synthesis of highly monodispersed mesoporous anatase titanium dioxide (TiO2) nanoparticles has been reported in this work. The mesoporous nanoparticles were obtained by a facile sol-gel method where titanium isopropoxide (TTIP) was used as the titanium precursor in basic solution. Here, the effect of reaction time was studied to study the growing mechanism of TiO2 nanocrystal. The as-synthesized nanoparticles were characterized with X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), Brunauer-Emmett-Teller (BET) Surface Area Analyzer, and High Resolution Tunneling Electron Microscopy (HR-TEM). Based on the result, it is found that a highly monodispersed mesoporous anatase TiO2 nanoparticles with large surface area could successfully be synthesized. It is also believed that the morphology of as-synthesized particles could easily be controlled by the reaction time. Results show that uniform mesoporous TiO2 nanoparticles with perfect spherical morphology could be obtained when the reaction was performed in 3 hours of reaction time.

Facile template-free route to synthesis visible light respensive hollow TiO2 spheres

The monodisperse hollow TiO2 spheres (HTS) were fabricated by facile template-free route involving direct precipitation and etching reaction. Tetrabutyl titanate was used as titanium precursor to form amorphous TiO2 spheres (ATS) directly in ethanol-acetonitrile mixed solution. Then, the ATS were etched by F− with the protection of PVP to form HTS under hydrothermal reaction conditions. The physical and chemical characterizations of synthesized samples were conducted by SEM, TEM, XRD and UV–vis diffuse reflectance spectroscopy. Result showed that morphology and structure of HTS can be easily controlled by adjusting time of etching reaction. The HTS obtained by etching for 4 h exhibited good hollow structure with unique shell assembled with enriched nanothorns, and it possessed good photocatalytic activity under visible light irradiation.

Effect of dysprosium ion (Dy3+) doping on morphological, crystal growth and optical properties of TiO2 particles and thin films

Dy3+ doped (0.5, 2.5, 5 and 7.5 wt %) TiO2 particles and thin films were obtained by modified alcoholysis-sol-gel route using tetrabutyl orthotitanate as a precurspor. By controlling the hydrolysis of this precursor through alcoholysis reaction, monodisperse and spherical TiO2 particles were obtained. X-ray diffraction and Raman results confirmed that the Dy3+ doped TiO2 particles are composed of only anatase phase. The Dy3+ doping inhibited any phase transformation and slowed down the particle growth of anatase TiO2. Scanning electron microscopy of bare TiO2 showed monodisperse, spherical and non-aggregated particles. In contrast, the Dy3+doped TiO2 samples exhibited poor dispersity. The luminescence spectra show three characteristic bands at 481, 577 and 683 nm, which are due to 4F9/2 → 6H15/2 (blue), 4F9/2 → 6H13/2 (yellow), and 4F9/2 → 6H11/2 (red) transitions of trivalent Dy3+ ions. The photoluminescence study revealed the dependence of the luminescent intensity on dopant concentration in TiO2 particles.

Ammonium Perchlorate Encapsulated with TiO2 Nanocomposite for Catalyzed Combustion Reactions

Ammonium perchlorate (APC) is the most common oxidizer for highly energetic systems. The initial decomposition of APC is an endothermic process. This behavior withstands high activation energy and could render high burning rate. We report on the sustainable fabrication of TiO2 nanoparticles; a novel catalyzing agent for APC. Mono-dispersed TiO2 particles of 10 nm particle size were fabricated using hydrothermal processing. XRD diffractogram demonstrated highly crystalline structure. The synthesized colloidal TiO2 particles were effectively integrated into APC particles via co-precipitation technique. The impact of TiO2 particles (1 wt%) on APC thermal behavior was investigated using DSC and TGA. APC demonstrated an initial endothermic decomposition (with absorption heat of 102.5 J/g) at 242 °C, and two subsequent exothermic decomposition stages at 297.8 and 452.8 °C respectively. TiO2 offered a decrease in APC early endothermic decomposition by 80%. The two main exothermic decomposition stages were merged into one single stage with an increase in total heat release by 18%. These novel features could inherit titanium oxide particles unique catalyzing ability for advanced highly energetic systems.

Controllable synthesis of transparent dispersions of monodisperse anatase-TiO2 nanoparticles and nanorods

Controllable synthesis of monodisperse nanocrystals is still a great challenge. In this study, the control strategy of alcohol medium was developed to conveniently synthesize monodisperse anatase-TiO2 nanocrystals with controllable size and shape by sol-gel method combined with solvothermal treatment. The effects of the amount of stearic acid and water, and molecular structure of alcohol on the size, the shape and the dispersity of TiO2 nanocrystals were explored. The optimum synthesis conditions were achieved. Monodisperse TiO2 nanoparticles and nanorods were obtained by using linear and branched alcohols, respectively. The size of nanoparticles decreased from 12 to 5 nm with increasing carbon number of linear alcohol. The aspect ratio of nanorods was adjusted from 1 to 5 by selecting alcohols with different locations of branched methyl group. The as-prepared monodisperse TiO2 nanocrystals could be readily dispersed in some commonly-used solvents to form transparent nanodispersions. Furthermore, a possible formation mechanism was also investigated.

Thermal and Photocatalytic Reactions of Methanol and Acetaldehyde on Pt-Modified Brookite TiO2 Nanorods

The influence of adding Pt on the catalytic and photocatalytic activity of monodispersed brookite phase TiO2 (B-TiO2) nanorods (NRs) was investigated. Pt was deposited on the NRs by photodeposition in solution, and the Pt-modified NRs were characterized using XPS, STEM, and LEIS. The thermal and photocatalytic activity of the Pt-modified NRs were then evaluated using temperature-programmed desorption (TPD) in ultrahigh vacuum (UHV). It was found that while Pt primarily acted as a site blocker for thermal reactions, Pt also acted as a recombination center for photogenerated electrons and holes, resulting in suppressed photocatalytic activity. Upon pretreatment with O2, however, the Pt-modified NRs exhibited enhanced photoactivity, indicating that adsorbed oxygen prevents electron–hole recombination by reacting with photogenerated conduction band electrons from the B-TiO2 to produce stable superoxide species on the Pt surface deposits. These results clearly demonstrate how the dynamics of charge carriers at...

Controllable one-pot synthesis of uniform colloidal TiO2 particles in a mixed solvent solution for photocatalysis.

This study reports on the controllable synthesis of uniform colloidal titanium dioxide (TiO2) particles and their photocatalytic applications toward rhodamine B (RhB) degradation. The monodispersed TiO2 particles were synthesized under mixed solvent conditions by sol–gel chemistry in a one-pot process. Varying the ratio of solvent composition, the concentration of surfactant and TiO2 precursor was used to control the particle diameter, degree of monodispersity and morphology. The modification of the calcination temperature affected the crystallinity and crystalline phase of the colloidal TiO2 particles. When uniform, amorphous TiO2 particles were calcined at an optimal temperature (500 °C), the final sample exhibited beneficial characteristics such as high anatase crystallinity with a mixed phase of anatase and rutile and relatively high surface area. The photocatalytic efficiency of the uniform TiO2 sample with high anatase crystallinity with mixed phase and high surface area was dramatically enhanced towards RhB degradation under UV–vis irradiation. We systemically discuss the relationship between the synthetic parameters in our synthesis and the properties of the final TiO2 products, as well as the crystalline properties and performance enhancement of TiO2 photocatalysts calcined at different temperatures.

One-pot synthesis of oleic acid modified monodispersed mesoporous TiO2 nanospheres with enhanced visible light photocatalytic performance

Herein, we report a facile one-pot solvothermal method to prepare unique oleic acid (OA) modified monodispersed mesoporous TiO2 nanospheres with carboxylate ligands from the oleic acid in the bidentate chelating linkage mode. The mesoporous OA-TiO2 nanospheres have a very large specific surface of nearly 510 m2/g. The oleic acid cannot only act as a binding ligand to control the shape of mesoporous TiO2 nanospheres, but also be benefit to enhance the visible-light absorption. The mesoporous OA-TiO2 nanospheres exhibit an excellent photocatalytic performance in the degradation of Rhodamine B and phenol under the visible light irradiation and show almost no attenuation after four cycles.

Ligand-exchange TiO2 nanocrystals induced formation of high-quality electron transporting layers at low temperature for efficient planar perovskite solar cells

Exploration of low-temperature solution-processed methodology for fabricating planar perovskite solar cells (PSCs) is meaningful for simplifying manufacturing, roll-to-roll industrial mass production on flexible substrates and designing perovskite tandem devices. However, some complicated, time consuming, or even high-cost methodologies such as atomic layer deposition, magnetron sputtering, and utilizing careful interface engineering are still needed for preparing efficient planar PSCs with TiO2 electron transport layers (ETLs) at low temperature. Here, we report a simple ligand-exchange strategy to overcome the problems. We use oleic acid (OA) molecules as surface ligands for synthesis well crystalline and monodisperse TiO2 nanocrystals. Subsequently, instead of high temperature decomposition, we find that the ligand-exchange strategy can also totally peel off these insulating ligands on the TiO2 nanocrystal surfaces and form high-quality TiO2 ETLs at low temperature. The OA-free TiO2 ETLs prepared at 150°C show high conductivity, fast electron extraction and transport speeds, low series resistance and high shunt resistance in the assembled PSCs, contributing to high performance devices with slight hysteresis and good reproducibility.

The preparation of TiO2@rGO nanocomposite efficiently activated with UVA/LED and H2O2 for high rate oxidation of acetaminophen: Catalyst characterization and acetaminophen degradation and mineralization

The present work was focused on the preparation of TiO2@rGO nanocomposite using an innovative facile synthesis method and the investigation of its photocatalytic activity in a UVA/LED photoreactor. The XRD patterns indicated anatase structure for all samples. Presence of rGO in nanocomposites was confirmed by FT-IR and Raman spectra. Also, mono-dispersed TiO2 nanoparticles on rGO sheet were shown in the SEM and HRTEM images. The prepared TiO2@rGO nanocomposite was used as the photocatalyst for degradation of acetaminophen (ACT) in the photoreactor illuminated with UVA/LEDs having the intensity of 95 µW/cm2. The complete degradation of 50 mg/L ACT was attained within 50 min in the LED/TiO2@rGO process while P25/LED process only showed 17% ACT degradation under similar experimental conditions. The photocatalytic activity was strongly affected by the rGO to TiO2 ratio in the nanocomposites and the highest photocatalytic activity was observed at 3.0 wt.% of rGO. Reaction with free OH was the main mechanism involved in the ACT photodegradation in the TiO2@rGO/LED process under the selected conditions. The performance of LED/TiO2@rGO process improved by four and three times in ACT degradation and mineralization, respectively, at the presence of H2O2. As made TiO2@rGO nanocompsite could preserve its catalytic activity during five consecutive recycles in the process. Accordingly, TiO2@rGO nanocomposite is an active and stable catalyst in the UVA/LED photoreactor for high rate degradation of pharmaceuticals in the contaminated water.

Enhanced capability and cyclability of flexible TiO2-reduced graphene oxide hybrid paper electrode by incorporating monodisperse anatase TiO2 quantum dots

Metal oxide nanoparticles as the electrochemically active second phase were incorporated into the paper-like flexible graphene-based hybrid electrodes. Its size and dispersion are crucial factors for determining the rate capability and cycling stability of the flexible hybrid paper electrode. Herein, we employ in-situ formed ultrafine monodisperse TiO2 quantum dots (QDs, ∼4.0 nm) as the electrochemically active second phase, which are uniformly incorporated into the flexible hybrid paper via a simple mixed solvothermal reaction together with a vacuum filtration, aiming at achieving a high-rate and long-cycle flexible TiO2-based anode in lithium ion batteries (LIBs). By combining the advantages of both ultrafine TiO2-QDs and three-dimensional (3D) conductive networks, the as-fabricated TiO2-QDs-reduced graphene oxide (TiO2-QDs-RGO) hybrid paper electrode shows high reversible capacity of 201 mA h g−1 after 100 cycles at 0.1 A g−1 and superior rate capability as well as long cycle life of 1500 cycles with ∼80.6% capacity retention at 2.0 A g−1. Detailed electrochemical analysis shows that the improved capability and cyclability of the hybrid paper electrode results from the integrated intercalation-based and interfacial lithium storage behaviors as well as the 3D fast electron/ion transfer of materials, which is ascribed to the ultra-small size of TiO2-QDs and the 3D self-standing conductive networks of the hybrid paper electrode. The results demonstrate the distinct advantages of our material design strategy, and also might pave the way for further studies of other flexible metal oxide/graphene hybrid paper electrodes for fast and long-life flexible anodes in LIBs.