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[Display omitted] • ZIF organogels with ethanolamine hetero-coordination were synthesized via the modified sol-gel method. • The pore size of ZIF makes the formation of free –NH 2 and associated –NH 2 for EtA. • It exhibited the widest effective bandwidth of 6.59 GHz when the thickness is 2.19 mm. • Two dipole polarization losses dominate EMW attenuation, and the intensity inversion occurs when the size of ZIF changes. Metal–organic framework (MOF) gels offer the potential for tunable electromagnetic wave (EMW) absorption owing to their customizable MOF cross-linked networks and strongly polar liquids. This overcomes the drawbacks of traditional MOF-derived absorbers; however, the corresponding EMW loss mechanism is absent. Here, a zeolite imidazole framework (ZIF) was used as a functional unit in conjunction with ethanolamine (EtA) hetero-coordination and methanol to fabricate ZIF organogels with the desired EMW absorption. The pore size of ZIF maintains the permeability for EtA and the methanol-barrier properties, which results in the formation of free –NH 2 and associated –NH 2 for EtA. The two corresponding species of dipole polarization losses provide additional EMW attenuation. Furthermore, the intensity inversion of the dual relaxation modes caused by the change in the size of the ZIF colloidal particles was used to improve the EMW absorption for the first time. ZIF organogels exhibited a strong correlation between dielectric properties and metal node species/EtA coordination density/hydrogen bonds, indicating that the absorption properties can be accurately regulated. Me-ZnCo-1 sample demonstrates the optimal effective absorption bandwidth of 6.59 GHz at 2.19 mm. This study not only elucidates the EMW loss mechanism of ZIF organogel networks but also proposes a creative design strategy for EMW-absorbing MOF gels. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-step sol-gel method synthesizes ZrP coating on AT-Ti. • ZrP coating enhances friction resistance of AT-Ti. • ZrP modification augments Ti's bioactivity. • ZrP effectively enhances Ti's osteogenesis properties. Titanium implants are widely used in dental restorations for patients suffering from dentition defects. However, the biologically inert of Ti, poor osteoinduction properties and the release of Ti particles due to friction between the bone and the implants can inhibit osseointegration and adversely affect the success rate of implantation. In this study, a zirconium phosphate (ZrP) coating was constructed on the surface of alkali thermal titanium (AT-Ti) via a one-step sol–gel approach. Subsequently, the friction resistance, bioactivity, and osteogenesis properties of the prepared coating were studied. The surface characterization results confirmed that AT-Ti was successfully coated with amorphous ZrP, and ZrP modification was found to effectively reduce the friction rate. In addition, the surface morphology after friction test was smoother. In terms of the bioactivity, the presence of a phosphate group in the ZrP coating led to the effective enrichment of Ca2+ to promote the formation of hydroxyapatite (HAp). It was also discovered that ZrP exhibited an excellent performance in cell viability and mineralization experiments, in addition to up-regulating the expression of osteogenesis related genes. Overall, ZrP modification of AT-Ti leads to an excellent friction resistance, bioactivity, and osteoinductive properties, thereby indicating its broad application prospects in implant therapy. [ABSTRACT FROM AUTHOR]

[Display omitted] • SC-NCM622 was synthesized by LiTaO 3 surface coating with Ta5+ injected. • Lattice mismatch and intragranular crack upon cycling were suppressed. • Irreversible oxygen release was effectively inhibited after modification. • LTO@NCM622 show higher capacity retention and cycling stability at 10 C. Ni-rich single-crystal layered cathodes, LiNi x Co y Mn z O 2 (SC-NCM, x ≥ 0.6), have been considered as the most favorable candidates for next-generation high-performance batteries. However, the rapid lithium concentration gradient and increased oxygen vacancies, caused by electrode/electrolyte interface degradation, are the primary reasons leading to the formation of irreversible intergranular cracks and the deterioration of material properties. Herein, the dual-modified LiNi 0.6 Co 0.2 Mn 0.2 O 2 (SC-NCM622) nanoparticle with LiTaO 3 protective layer containing Ta5+ is synthesized by a facile sol–gel method. The dual-modified strategy could provide rapid lithium-ion channels, effectively relieving stress evolution, polarization, and dynamic degradation of cathode materials during cycling. This strategy hinders the formation of oxygen vacancies on the cathode surface and prevents the development of intragranular cracks. As expected, the 2 wt% LTO@SC-NCM622 exhibits excellent capacity retention of 90.39 % at 1 C after 200 cycles. Even at 10 C, the 2 wt%LTO@SC-NCM622 retains a specific capacity of 88.7 mAh g−1 (82.7 %) after 500 cycles. This work offers guidance for the design of new stable Ni-rich cathodes for next-generation LIBs. [ABSTRACT FROM AUTHOR]

The facile synthesis of a new class of reactive hydrogen polysilsesquioxane (HPSQ, (HSiO 1.5) n ,) hollow spheres is reported in this work. HPSQ hollow spheres can be controllably fabricated from triethoxysilane (TES, HSi(OEt) 3) as a sole precursor through a polystyrene template-directed sol–gel process under aqueous acid-catalyzed conditions followed by template removal. The particle size and shell thickness of the spheres could be fine-tuned by utilizing different amounts of TES. Total preservation of Si H bonds and formation of a Si-O-Si framework in the HPSQ hollow spheres are confirmed by FTIR and 29Si NMR. Reactive Si H moieties combined with a hollow structure make HPSQs suitable as carriers for noble metal nanoparticles. HPSQ hollow spheres function not only as a host that can adsorb Ag ions but also as a mild reducing agent for these ions. TEM studies show that the synthesized AgNPs are dispersed well on the HPSQ hollow spheres with an average particle size of 2–10 nm. XRD studies indicate that the resulting AgNPs are highly crystalline with a face-centered cubic geometry. SEM-EDS shows that the Ag content on the selected surface is 4.76 wt%. HPSQ hollow spheres loaded with AgNPs exhibit high performance when utilized as a catalyst to reduce methylene blue. Unlabelled Image • Hollow spheres from hydrogen polysilsesquioxane were controllably fabricated. • Silane precursor content determined the shell thickness of the hollow spheres. • Reactive Si H groups on HPSQs could reduce Ag ions directly. • Ag/HPSQ hollow spheres for rapid reduction of methylene blue • The uniform and reactive HPSQ materials may open new uses in catalysts and such. [ABSTRACT FROM AUTHOR]

A series of 3V-xFe/MgF 2 catalysts with different V/Fe molar ratios were prepared by a sol-gel method, and the effect of Fe promotion on the catalytic performance of gas-phase dehydrofluorination of 1,1,1,3,3-pentafluoropropane (HFC-245fa) was investigated. It was found that proper V/Fe ratio was helpful to improve the activity. The 3V-0.5Fe/MgF 2 catalyst (with a V/Fe ratio of 6/1) gave a HFC-245fa conversion of 76.6% at 320 °C, which was 13.4% higher than that on the 3V/MgF 2 (63.2%). The synergy between V and Fe species resulted in enhanced surface acidity which accounts for the enhanced activity. The VO x and FeO x species in the fresh catalyst could be transformed to VOF x and FeF 3 species during the reaction, which were regarded as the active sites. However, higher content of Fe in the catalyst resulted in the partial coverage of V species, which led to decline of surface acidity and thus the suppressed activity. Also, surface carbon deposition was responsible for the slight catalyst deactivation. Unlabelled Image • 3V-xFe/MgF 2 catalysts with different V/Fe molar ratios were prepared by a sol-gel method. • The incorporation of Fe and V with proper molar ratio improves the performance. • VOF x and FeF 3 species transformed from VO x and FeO x during the reaction are the active sites. • VOF x is more intrinsically active than the FeF 3. • Slight catalyst deactivation was due to the surface carbon deposition. [ABSTRACT FROM AUTHOR]

According to the World Health Organization (WHO) neglected diseases (ND) afflict the lives of one billion people in the world. Tuberculosis is a ND, being the leading cause of death in the world. Isoniazid (INH) is one of the most commonly used antibiotics in the treatment of tuberculosis. The present study synthesized a nanocarrier for INH using expanded perlite as an alternative source of silica to obtain the precursor for NPS synthesis by the modified Stöber method (sol-gel process). The optimization of NPS synthesis of different size (178.8 to 559.1 nm) and size distribution (mono and bimodal) was performed, presenting an excellent synthesis efficiency (99.79%) and fast (without many steps, complicated apparatus or reagents of high toxicity) and easy to perform. The experimental design was used to optimize the INH incorporation process in NPS, with the optimal conditions of INH incorporation: 0.075 mg/mL, pH 2, 24 h and 600 mg of nanocarrier (NPS). The pH-dependent system of INH + NPS was promising to improve the bioavailability and consequent better absorption of INH, since it ensured a more efficient release in intestinal pH and with a larger fraction of non-ionized molecules due to the resulting interaction between INH and NPS. Unlabelled Image • Nanoparticles of silica were obtained quickly, simply and with excellent yield. • The silanol groups ensure a pH-responsive surface of the nanoparticles of silica. • The pH-dependent system is promising for improved bioavailability of isoniazid; • Isoniazid is released from nanoparticles of silica slowly and pH-dependent. [ABSTRACT FROM AUTHOR]

The aim of the study was the production of ceramic SiO 2 nanowires using the sol-gel and electrospinning methods from a PVP/TEOS/AcOH/EtOH solution. The obtained fibrous mats underwent preliminary drying at room temperature. Then, they were subjected to the calcination process in air to obtain pure amorphous silicon dioxide nanowires. A scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS) was used in order to carry out an analysis of the morphology and chemical composition of the resulting nanowires. A high-resolution transmission electron microscope (TEM) was used along with X-ray diffraction analysis (XRD) in order to analyse the structure of the obtained materials. Besides, thermogravimetric analysis (TGA) was performed to show polymer concentration loss in the function of temperature in the obtained two types of PVP/SiO 2 nanofibers. The analysis of the optical properties and the energy band gap of the prepared nanowires was determined by spectral analysis using a UV–Vis spectrophotometer. Using the method proposed by the authors and the recorded absorbance spectra determined the banded refractive index n, real n′ and imaginary k part of the refractive index as a function of the wavelength, complex dielectric constant ε, real and imaginary part ε r and ε i of the dielectric constant as a function of the wavelength of the SiO 2 nanowires. The obtained results, which were as follows: energy band gap of 3.93–3.97 eV, complex refractive index coefficient values of 1.52–1.65 and dielectric constant in the range of 2.30–2.73, suggest the possibility to control the morphology and optical properties of the produced nanomaterial. • The PVP/SiO2 composite nanofibers and SiO2 nanowires obtained using the electrospinning and sol-gel methods • The effect of process parameters on their morphology was investigated • The effect of share of precursors and process parameters on their optical properties were investigated [ABSTRACT FROM AUTHOR]

The structural and electronic properties on Nd 0.6- x Bi x Sr 0.4 MnO 3 nano powders with x = 0, 0.05 and 0.1 are reported. The compounds were prepared using sol-gel combustion method. X-ray diffraction studies confirm that all samples crystallize in orthorhombic structure having Pnma space group. The powders consist of spherical particles that tend to agglomerate, with average grain sizes of about 40–50 nm. XPS measurements reveal a shift toward lower binding energies of Mn 3 s , Mn 2 p , Nd 3 d , and O 1 s core levels with increasing Bi content, which can be explained by the larger 'c' lattice parameter and therefore larger atomic distances. The analysis of the core level XPS spectra proves the existence of both Mn4+ and Mn3+ ions in all samples, as well as the localization of Bi3+ ions in the perovskite lattice. The XPS valence-band is dominated by extensively hybridized Nd 4 f -O 2 p states, with contributions from Mn 3 d -O 2 p bonding and Mn 3 d states. • Nd 0.6- x Bi x Sr 0.4 MnO 3 nano-powders were synthesized via sol-gel combustion method. • TEM images show 20 to 50 nm spherical particles that tend to agglomerate. • XPS spectra prove the existence of both Mn4+ and Mn3+ ions in all samples. • XPS valence-band spectra are due mainly to hybridized Nd 4 f -O 2 p and Mn 3 d states. [ABSTRACT FROM AUTHOR]

Herein, sol-gel based synthesis of poly ethanol glycol assisted gold nanodendrites (AuNDs) is reported at low-temperature. Taking advantage of its facile synthesis, phenolphthalein (phph) is encapsulated/immobilized in AuNDs for the assay of fiber optic pH sensing. Hierarchical structure is observed by FE-SEM analysis before and after phph encapsulation. EDX analysis confirms the uniform distribution of elements with smooth morphology. AFM analysis shows that phph encapsulated AuNDs have low average roughness (2 nm) and less thickness ~20 nm. The chemical bonding between phph species and Au molecules are explored by FTIR analysis. The polycrystalline nature of AuNDs matrix before and after encapsulation is confirmed by XRD. HR-TEM analysis exhibited preferential growth of dendrites structure before and after encapsulation along (111) direction. UV–Vis analysis shows that AuNDs has refractive index 1.24 at 550 nm, which reduces down to 1.18 at 550 nm after phph encapsulation. 30 cm coated middle segment of plastic clad silica fiber (PCS) is used as sensor. Variations in output intensities in terms of transmission are used to characterize the sensor response. A fast response ~0.87 s, repeatability/reproducibility and linear response (R2 = 0.8912) is obtained at 440 nm. Acidity of rainwater (pH 6) is determined by prepared sensor for validity purpose and practical applications. Unlabelled Image • Polyethanol glycol assisted gold nanodendrites (AuNDs) are synthesized by low temperature sol-gel method. • Uniform distribution of elements with smooth morphology are reported. • Phenophthalein encapsulated AuNDs has refractive index 1.18 at 550 nm after. • Acidity of rainwater (pH 6) is determined by prepared sensor for validity purpose and practical applications. • A fast response ~0.87 s, repeatability/reproducibility and linear response (R2 = 0.8912) is obtained at 440 nm. [ABSTRACT FROM AUTHOR]

Chemical-looping reforming of methane (CLRM) offers an effective approach for the production of syngas. A series of Ce x Zr y Cu 1−x−y (x = 0.6, 0.7, y = 0–0.35) mixed oxides were successfully prepared by sol-gel method, and characterized by means of XRD, H 2 -TPR, BET, XPS, Raman and CH 4 -TPR. The addition of Cu and Zr ions caused the distortion of CeO 2 lattice and induced more oxygen vacancies, which promoted the mobility of lattice oxygen in the materials. Ce x Zr y Cu 1−x−y mixed oxides also owned smaller grain size and better thermal stability than pure CeO 2 -CuO mixed oxides. Among the series of Ce x Zr y Cu 1−x−y mixed oxides, the reducibility of Ce 0.6 Zr x Cu 0.4−x and Ce 0.7 Zr x Cu 0.3−x samples gradually increased with the Cu content. It was found that the Ce 0.7 Zr 0.2 Cu 0.1 sample owned the most abundant oxygen vacancies on the surface. The Ce x Zr y Cu 1−x−y mixed oxides with lower Cu content (≤0.1) produced higher amount of H 2 and CO while smaller CO 2. Ce 0.7 Zr 0.2 Cu 0.1 sample still retained better structural stability and thermal stability after 20 times cycled reaction. In the present work, we synthesized a series of Ce x Zr y Cu 1−x−y (x = 0.6, 0.7, y = 0–0.35) mixed oxides by sol-gel method. The Ce 0.7 Zr 0.2 Cu 0.1 sample still retained better structural stability and thermal stability than Ce Cu samples during the successive chemical-looping reforming of methane (CLRM) process. Unlabelled Image • The addition of Cu and Zr caused the distortion of CeO 2 lattice, inducing more oxygen vacancy and better oxygen mobility. • Ce x Zr y Cu 1−x−y mixed oxides also owned smaller grain size and better thermal stability than pure CeO 2 -CuO mixed oxides. • Ce 0.7 Zr 0.2 Cu 0.1 sample still retained better structural stability and thermal stability after 20 times cycled reaction. [ABSTRACT FROM AUTHOR]

Abstract SiO x (0 < x < 2) based materials are attractive for developing high-capacity and durable anodes toward superior lithium storage. Herein, low cost and tailorable core-shell SiO@TiO 2 nanocomposites have been synthesized via simple ball milling and sol-gel process. The designed nanocomposite is composed of nano-sized SiO as the inner core and amorphous TiO 2 layer as the shell. Remarkably, when used as anode material for lithium-ion batteries, the SiO@TiO 2 exhibits greatly enhanced capacity performance and cycling stability due to its rational core-shell structure. The optimal nanocomposite delivers a high initial specific capacity of 1920 mA h g−1 with high initial coulombic efficiency of 79.4%, along with a stable reversible capacity of 901 mA h g−1 after 200 cycles at 200 mA g−1 and impressive high-rate capacity of 272 mA h g−1 at 3000 mA g−1. The excellent electrochemical performance of the nanocomposite is contributed by the synergetic core-shell structure, in which the amorphous TiO 2 shell can not only act as protective/elastic buffer layer to accommodate the volume change of the SiO nanoparticles upon cycling, but also largely favor the Li+ diffusion in the nanocomposite toward highly reversible lithium storage. In virtue of the simple, green and scalable fabrication process, these robust and efficient nanocomposites are promising to realize inexpensive and high-performance lithium ion batteries anodes and related energy storage applications. Graphical abstract A core-shell SiO@TiO 2 nanocomposite was synthesized via an economic and scalable process and exhibits greatly enhanced capacity with high initial coulombic efficiency and excellent cycling stability as LIBs anode. Unlabelled Image Highlights • Core-shell SiO@TiO 2 nanocomposite was synthesized via an economic and scalable process. • Amorphous TiO 2 shell acts as a protective/elastic buffer layer for SiO nanoparticles. • The TiO 2 shell also largely favor the Li+ diffusion toward highly reversible lithium storage • It exhibits greatly enhanced capacity with high initial coulombic efficiency and excellent cycling stability as LIBs anode. [ABSTRACT FROM AUTHOR]

Abstract Z -Scheme Ag/TiO 2 /AgMIL-101(Cr) was prepared by co-doping Ag and TiO 2 with AgMIL-101(Cr) via solvothermal synthesis combined with sol-gel method. Ag and anatase TiO 2 nanoparticles were well dispersed on the surface of AgMIL-101(Cr) with octahedral structure. 5 wt% Ag and 50% TiO 2 co-doping on the AgMIL-101(Cr) (Ag 5 T 50 Ag 5 M) exhibited large specific surface area (346.5 m2·g−1) and narrow band gap 2.16 eV. Only 10 min of UV light irradiation resulted in the conversion of nitrate and nitrogen selectivity up to 100% over Ag 5 T 50 Ag 5 M. After 5 cycles of nitrate removal, the conversion of nitrate remained 90% indicating that catalyst had stable reusability. Moreover, instead of formic acid, ofloxacin (OFX) was used as a hole scavenger to evaluate the ability of Ag 5 T 50 Ag 5 M for the nitrate reduction. The result showed that the concentration of OFX was important factor to affect the conversion of nitrate. Based on the above discussion about the characterization and photocatalytic nitrate reduction, combined with the photoluminescence and electrochemical measurement results, the enhanced conversion of nitrate and nitrogen selectivity was reasonably explained. Finally, the route of electron transfer during the three constituents constructed Z -Scheme system and the mechanism of nitrate reduction to nitrogen was presumed. Highlights • First example of Z -Scheme Ag/TiO 2 /AgMIL-101(Cr) for NO 3 − reduction. • Ofloxacin instead of traditional formic acid as hole scavenger was investigated. • Z-Scheme mechanism over Ag/TiO 2 /AgMIL-101(Cr) for photoreduction nitrate was proposed. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Investigation for thermochromic properties of VO 2 thin films with different pattern size was done. • Pattern size was varied as a diameter of polystyrene spheres with 550, 900, and 1230 nm. • It was found that pattern size strongly effect on transmittance curves in certain wavelength. • With increasing pattern size, a changing point of transmittance curve were shifted to long wavelength. • This phenomena are good agree with Bragg condition presented in manuscript. Abstract This paper presents the optical characteristics of 2D honeycomb structured vanadium dioxide (VO 2) thermochromic thin films with different pattern size prepared by sol-gel method with adopting colloidal lithography. Pattern sizes of films were varied as a diameter of polystyrene spheres and size of obtained films are 550, 900, and 1230 nm, respectively. Crystal structure of prepared films is monoclinic phase of VO 2 (M) and there are no impurities or other oxides. The transmittance curve change was observed for all patterned VO 2 thin films and it is strongly correlated with pattern sizes and shapes which can make difference in photonic band gap. In addition, it is found that such transmittance curve change are originated from reflection at certain wavelength section which confirmed by reflectance spectra. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • TiNb 2 O 7 nanowires were obtained by sol-gel method with SPNTs as the template. • TiNb 2 O 7 nanowires assembled from nanoparticles gathered merits of 1D structure. • The obtained TiNb 2 O 7 nanowires exhibit outstanding electrochemical properties. Abstract TiNb 2 O 7 nanowires (TNS) were synthesized by using a simple sol-gel method combined with subsequent calcination process. As anodes of lithium-ion batteries, TNS exhibit a specific capacity of 199.6 mAh g−1 after 500 cycles at 0.4 A g−1 and satisfactory coulombic efficiency of 98.7% after 2000 cycles at 5 A g−1. Compared with TiNb 2 O 7 nanoparticles (TN), TNS have excellent electrochemical performances due to the 1D materials assembled from uniform and dense TiNb 2 O 7 nanoparticles (∼35 nm). The 1D linear structural electrode gathered the merits of tiny nanoparticles, multiple active sites, short electronic transport path and excellent dynamics orientation, which are responsible for the favorable electrochemical properties. [ABSTRACT FROM AUTHOR]

Highlights • New sol-gel technique for Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) solid electrolyte powder was proposed. • Dense and single-phase LATP solid electrolyte could be obtained at 1000 °C for 6 h. • LATP solid electrolyte showed high lithium ion conductivity of 4.2 × 10−4 S/cm at 25 °C. Abstract Sodium super ionic conductor (NASICON)-type solid electrolytes, Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP), have high lithium ion conductivity and chemical/electrochemical stability. In this study, we proposed a new sol-gel route to synthesize LATP precursor powder. The LATP powder was prepared from lithium nitrate (LiNO 3), aluminum phosphate (AlPO 4), ammonium phosphate (NH 3 PO 4), and titanium isopropoxide (Ti-(OCH(CH 3) 2) 4). The LATP electrolyte with high relative density (99%) and lithium ion conductivity (4.2 × 10−4 S/cm at 30 °C) could be fabricated by sintering the precursor powder at 1000 °C for 6 h. XRD analysis results revealed that the electrolyte sample sintered at 1000 °C for 6 h was impurity-free single phase LATP. FE-SEM observations showed that the grain size and density increased with increasing sintering temperature. AC impedance spectra and SEM observations suggest that the enhanced lithium ion conductivity was due to an increase in grain size and density of the LATP electrolyte. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • SmNbO 4 (SNO) and SmTaO 4 (STO) precursors were prepared by sol-gel method. • Effect of samarium in Nb5+ and Ta5+ structures was studied using XPS method. • Binding energy differences revealed characterize average Nb O and Ta O bonding. • XPS confirmed Sm3+ and Sm2+ valence states in ratio 21/1 (SNO) and 24/0.3 (STO). Abstract Samarium niobate SmNbO 4 (SNO) and tantalate SmTaO 4 (STO) precursors were prepared by sol-gel method and annealing at 1000 °C. The different polymorphs, orthorhombic and monoclinic SmNbO 4 or tetragonal SmTa 7 O 19 and monoclinic SmTaO 4 were identified. Structural properties of precursors were investigated by the X-ray photoelectron spectroscopy (XPS). Core-level XPS studies of sol-gel SNO and STO were performed for the first time. The binding energy differences Δ(O Nb) = B E (O 1s) – B E (Nb 3d 5/2) and Δ(O Ta) = B E (O 1s) – B E (Ta 4f 7/2) were used as suitable parameter to characterize average Nb O bonding in SNO (323.1 eV) and Ta O bonding in STO (503.9 eV). The Sm 3d 5/2 peak consists of strong features characteristic for Sm3+ (1083.0 eV) with (4f5) electron configuration and Sm2+ (1072 eV) with (4f6) electron configuration. The molar concentration of Sm3+ in SNO and STO was higher (21.0 and 24.7 at.%) than Sm2+ in SNO (1.0 at.%) and STO (0.3 at.%). The XPS demonstrated two valence states of Sm in precursors for application as nanophosphors for lighting and display technologies. [ABSTRACT FROM AUTHOR]

Highlights • Synthesis of plasmonic nanoparticles were done in a cost effective method. • Identified a novel tool to fine tune plasmonic absorption band. • Developed a SiO 2 matrix with homogeniously distributed Ag nano particles. Abstract The plasmonic responses of silver nanoparticles are having attention due to their potential applications in plasmonic solar cell. We successfully synthesised silver nanoparticles in silica matrices by means of hydrolytic sol–gel method. The sol-gel derived samples were effectively annealed at 400 °C, 600 °C, 800 °C and studied the plasmonic response of silver nanoparticles. The temperature and doping concentration dependence of the nanoparticles and their optical and structural response were well studied. The Fourier-transform infrared spectroscopy (FTIR) confirmed the SiO 2 formation. The XRD data confirmed the crystalline nature of Ag nanoparticles and the size is calculated to be 20 nm. The Transmission Electron Microscopy (TEM) measurement confirmed the crystalline planes of silver nanoparticles and the particle size is found to be around 20 nm. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Microwave-assisted method was used to synthesize BiFeO 3 nanoparticles. • "A" site affected physicochemical properties and photoelectrochemical activity. • Jahn-Teller distortion enhanced photocatalytic activity. • The photoactivity showed dependence to A site substitution. Abstract BiFeO 3 (BF) and LaFeO 3 (LF) perovskites were synthesized using a microwave-assisted (MW) and sol-gel (SG) methods. XRD, XPS, TEM, UV-DRS techniques were applied to study physicochemical properties of perovskites. In addition, Incident Photon-to-Current Efficiency (IPCE) measurements, Linear Sweep Voltammetry (LSV) and impedance spectroscopy were used to characterize electrochemical properties of the materials. The band gap energy increases in the following way: BF-MW (2.05 eV), LF-MW (2.18 eV), BF-SG (2.26 eV) and LF-SG (2.54 eV), demonstrating a remarkable influence of the synthesis method on the optical and electronic properties of the materials. Furthermore, XRD showed a significant impact of the synthesis methods on the crystal structure. Perovskites synthesized under MW irradiation showed a pure crystal structure compared to the perovskites prepared by SG method, which contained some admixtures. IPCE shows that LF-MW has a better charge separation ability compared to BF-MW. However, BF-SG showed the highest activity. Temperature programmed reduction tests (TPR) revealed a better ability of BF-MW to adsorb/desorb oxygen, compared to LF-MW. XPS measurements pointed at the presence of Fe4+. Finally, the photocatalytic activity of the perovskites was tested in solar water-splitting as a function of the synthesis method and presence of Bi and La in "A" sites of the ABO 3 perovskites. We postulate, that the Jahn-Teller distortion effect in LF-MW increases its catalytic activity by decreasing the binding energy compared to BF-MW. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Novel ZnO:PEIE nanocomposites are prepared by an in-situ synthesis method. • PEIE as a doping agent effectively prevent the aggregation of ZnO nanoparticles, • The mixture of PEIE modify and passivate surface of ZnO nanoparticles. • The performance of the device with ZnO:PEIE (0.1 wt% PEIE) is obviously improved. Abstract In this study, novel nanocomposites consisting of zinc oxide (ZnO) and a polymer polyethylenimine ethoxylated (PEIE) are fabricated by blending sol–gel ZnO dispersions with different concentrations of PEIE in solution. The photoelectric properties of ZnO:PEIE composites are characterized by a series of testing methods. The results show that PEIE as a doping agent can effectively modify and passivate the surface of ZnO nanoparticles, and ZnO:PEIE composite at 0.1 wt% PEIE possesses the highest conductivity and the lowest work function. Moreover, the ZnO and ZnO:PEIE composites with different concentrations of PEIE are used as electron transport layers (ETLs) in polymer solar cells (PSCs). Compared to pure ZnO as ETL, the power conversion efficiency (PCE) of the device based on P3HT:PCBM with ZnO:PEIE (0.1 wt% PEIE) as ETL is effectively improved from 3.01% to 3.52%. For the device based on PTB7:PCBM with ZnO:PEIE (0.1 wt% PEIE) as ETL, the PCE is improved from 6.92% to 8.03%. It is found that PEIE can not only reduce the surface defects and traps of ZnO nanoparticles, but also prevent the aggregation of ZnO precursor. Moreover, the addition of PEIE does not change the shape of synthetic nanometer ZnO materials, and the Fermi level of ZnO thin films is also gradually decreased with the addition of PEIE, which helps to reduce the electronic transmission barrier. Accordingly, ZnO:PEIE composites can be effective ETLs in PSCs. [ABSTRACT FROM AUTHOR]

Highlights • Photocatalytic reactor with floated glass balls was designed for photodegradation. • Glass balls were coated with Bi 2 O 3 /TiO 2 film and constantly rotated by air pumping. • Bi 2 O 3 /TiO 2 film was prepared by sol-gel route and improve visible light absorption. • Constant rotation of glass balls improved efficient contact and light utilization. • Efficient photoactivity and high durability were achieved for organics removal. Abstract A novel photocatalytic reactor was designed for the photo-degradation of organic pollutants with floated glass balls on the solution surface, which were constantly rotated by the air pumping and coated with Bi 2 O 3 /TiO 2 film. The uniform and stable Bi 2 O 3 /TiO 2 film was prepared by the facile sol-gel method at the optimal conditions of Bi Bi 2 O 3 content (1.0 mol%) and the three coating times with the film thickness of 210 nm. It was uniformly distributed and stably combined with the surface of the glass ball. Modification of Bi 2 O 3 significantly improved the visible light absorption of TiO 2 film and inhibited the photo-induced charges, promoting the photo-degradation activity. More importantly, the air pumping at the bottom of the reactor impelled the constant rotation of floated glass balls. It could realize the uniform aqueous membrane on the catalyst film to improve the efficient contact between catalyst and organics and to utilize the irradiation light efficiently, inhibiting the light shield effect of dyeing wastewater and facilitating the photo-degradation. Moreover, the Bi 2 O 3 /TiO 2 photocatalytic film in this photocatalytic reactor exhibited high durability and prevented the leakage of catalyst, providing a potential for the practical applications in the future. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Low temperature processing of hybrid dielectric gate layers by sol-gel. • Al 2 O 3 -GPTMS-PMMA hybrid films for applications as dielectric gate in TFT. • ZnO-based thin-film transistors with high Ion/Ioff current ratio. Abstract In this work we evaluate the synthesis of inorganic-organic Al 2 O 3 -GPTMS-PMMA hybrid films using a low temperature sol-gel process and their use as gate dielectric for thin film transistors (TFTs). The hybrid films were deposited by dip coating process and then annealed at 150 °C in air. The analysis of the hybrid films was performed by UV–VIS spectroscopy, FTIR, AFM, SEM, C-V and I-V measurements. The optical transparency above 85% in the visible range and homogeneity of the hybrid films support the proper link between inorganic and organic phases with strong bonds. At microscopic level, the hybrid films have uniform surface roughness lower than 1 nm. The C-V and I-V measurements performed on MIM structures showed leakage current density in the order of 10−7 A/cm2 at 104 kV/cm electric field. Capacitance and dielectric constant measured at 1 kHz were 20.4 pF and of 6.2, respectively. TFTs were fabricated using bottom gate and aluminium top contacts to obtain mobilities of 4.5 cm2/Vs, threshold voltage of 0.7 V and I on /I off ratio of 107, while mantaining operating voltage under 8 V. [ABSTRACT FROM AUTHOR]

Cu-CoO/N-doped carbon nanocatalysts can be designed by sol–gel method and they have high catalytic performances toward hydrogenation reduction reaction of 4-nitrophenol (4-NP), which is high toxic to environment. A high activity parameter of 2128 s−1·g−1 of the nanocatalyst being calcinated at 600 °C can be obtained when the molar ratio of NaBH 4 :4-NP is 100:1. [Display omitted] • Cu-CoO/N-doped carbon (Cu-CoO/NC) nanocatalysts were designed by sol–gel method. • Catalysts′ performance toward reduction reaction of 4-nitrophenol (4-NP) were tested. • Excellent catalytic behavior and synergistic effect occurs in these nanocatalysts. • Activity parameter can reach 2128 s−1·g−1 when molar ratio of NaBH 4 :4-NP is 100:1. • The catalyst can be used for 5 times without losing its catalytic performance. This work reports sol–gel designing of novel Cu-CoO/N-doped carbon (Cu-CoO/NC) nanocatalysts and their catalytic behavior toward hydrogenation reduction reaction of 4-nitrophenol (4-NP) in aqueous solution and reduction of Cr(VI) in water. The Cu and CoO crystalline phases and the microstructure of the nanocatalysts were determined by X-ray diffraction (XRD) analysis and transmission electron microscope. The catalytic performances of the nanocatalysts toward reduction reaction of 4-nitrophenol and Cr(VI) were evaluated by UV–vis absorption analysis and it was revealed that the Cu-CoO/NC nanocatalyst prepared at 600 °C had the best catalytic performance toward reduction of 4-NP with an activity parameter being 2128 s−1·g−1 when the molar ratio of NaBH 4 :4-NP was 100:1 and the mass of catalyst was 0.05 mg, and a high activity parameter of 3.51 s−1·g−1 toward reduction of Cr(VI) when the molar ratio of HCOOH: K 2 Cr 2 O 7 was 100:1 and the mass of the catalyst was 5 mg. The Cu-CoO/NC nanocatalyst could be reused for 5 times without losing its catalytic performance toward reduction of 4-NP. Our results provide a reliable way for the development of environmental protection. [ABSTRACT FROM AUTHOR]

The effect of Li+ doping on the structure and properties of the material and the reaction mechanism are fully explained by practical experiments combined with theoretical calculations. When the doping amount of Li+ is 0.2, Na 2.8 Li 0.2 V 2 (PO 4) 3 /C can provide a reversible capacity of 116.9 mAh/g, almost reaching the theoretical capacity (117 mAh/g). After 500 cycles, it shows an amazing capacity retention rate (99.82%). [Display omitted] • Based on the carbon coating, we discuss the Li+ substituted of Na 3−x Li x V 2 (PO 4) 3 /C (x = 0, 0.1, 0.2, 0.3, 0.4) series materials to achieve SIBs cathode materials comparable to the theoretical capacity. • The optimum doping amount is 0.2, Na 2.8 Li 0.2 V 2 (PO 4) 3 /C can provide a reversible capacity of 116.9 mAh/g, almost reaching the theoretical capacity (117 mAh/g). After 500 cycles, it shows an amazing capacity retention rate (99.82 %). • The effect of Li+ doping on the structure and properties of the material and the reaction mechanism are fully explained by practical experiments combined with theoretical calculations. Na 3 V 2 (PO 4) 3 (NVP) has become a hot material in the research field of sodium-ion batteries (SIBs) as a result of its unique structural advantages. Unfortunately, the poor electronic conductivity and ion diffusion ability fundamentally limit the practical development of NVP. Considering the above defects, a series of Li+ doped Na 3−x Li x V 2 (PO 4) 3 /C cathode materials for SIBs are synthesized through hydrothermal assisted sol–gel method. The cell volume steadily decline with the raise of Li+ doping amount, which is consistent with the usual doping effect. Moreover, with the increase of lithium doping amount, Li+ preferentially occupies Na (2) site and then occupies Na (1) site. Through the first principles calculation, it is clear that the introduction of Li+ can significantly reinforce the conductivity of the material system and diminish the electron localization phenomenon. The analysis of (1 1 6) crystal plane by TEM shows that Li doping will reduce the interplanar spacing. The change of V valence during the charge–discharge process of Na 2.8 Li 0.2 V 2 (PO 4) 3 /C is consistent with that of NVP by V element XANES characterization. There is no conventional phase transition phenomenon in the ex-situ XRD high-voltage charging state. The above facts indicate that lithium doping obtains a stable solid solution NVP. The electrochemical test results show that Na 2.8 Li 0.2 V 2 (PO 4) 3 /C can provide an amazing reversible capacity of 116.9 mAh/g (theoretical capacity of 117 mAh/g) and capacity retention rate of 99.82 % after 500 cycles. GITT results show that Li+ can significantly increase the Na+ diffusion coefficient of the material. Such excellent electrochemical performance is attributed to the fact that the doping of Li+ activates the activity of Na+ in Na (2) site and improves the reaction efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Introducing bismuth-doped WO 3 film into electrochromism for the first time. • Amorphous Bi-WO 3 film possess fast switching time and excellent stability. • Design and construct a proton-based aqueous electrochromic device. • Bi-WO 3 -based aqueous electrochromic device exhibits fascinating performance. Tungsten trioxide (WO 3) film, recognized as one of the most promising electrochromic materials due to its exceptional electrochemical characteristics, is extensively utilized in fabricating electrochromic devices. The use of bismuth-doped WO 3 (Bi-WO 3) films in photoelectrocatalysis has been extensively studied. However, its potential in electrochromism remains unexplored. Herein, amorphous Bi-WO 3 films with enhanced electrochromic performance are synthesized through a simple sol–gel method. The effects of Bi doping amount and sol concentration on the electrochromic properties of Bi-WO 3 films are investigated. The optimized Bi-WO 3 film displays excellent electrochromic performance, encompassing high optical contrast (ΔT = 81% at 630 nm), fast switching time (2.4/1.2 s for coloring and bleaching), and high coloration efficiency (55.84 cm2C−1). An electrochromic device is assembled utilizing an amorphous Bi-WO 3 film as the electrochromic layer with Cu foil as the counter electrode. The fascinating electrochromic properties of amorphous Bi-WO 3 thin films and the high activity features of proton enable the assembled ECD to have a suitable working voltage range (1.1 V) in aqueous electrolytes. Besides, the electrochromic device demonstrates outstanding properties (ΔT = 70%, t c = 3 s, t b = 0.9 s) and provides a helpful strategy for the facile processing of high-performance electrochromic devices. [ABSTRACT FROM AUTHOR]

Fe-Fe 3 N/3DNC materials prepared by sol–gel method have a multidimensional cross-linked framework structure consisting of one- and two-dimensional cross-links, and the abundant Fe-N x sites and nitrogen-rich carbon substrates can effectively enhance the ORR electrocatalytic activity. [Display omitted] • Safe and efficient synthesis of Fe-Fe 3 N/3DNC using sol–gel method. • Abundance of Fe-N x and N-C sites leads to excellent ORR catalytic activity. • Multi-dimensional cross-linked structure enhances electrochemical kinetics. • Fe-Fe 3 N/3DNC-1 surpasses Pt/C in zinc-air battery applications. • DFT calculation confirms the crucial role of Fe 3 N in enhancing performance. Taking into consideration the sluggish kinetics of the oxygen reduction reaction (ORR) and the distinct three-phase environment of the electrode, it is crucial to optimize the surface structure of the electrocatalyst. This study employs a sol–gel approach to synthesize a Fe-Fe 3 N composite three-dimensional nitrogen-doped carbon framework (Fe-Fe 3 N/3DNC) and utilize it as the electrocatalyst for a zinc-air battery. The material possesses a multi-dimensional cross-linking frame structure comprised of one-dimensional and two-dimensional crosslinks, which effectively reduce the diffusion mean-free path of oxygen. Moreover, the iron–nitrogen site and nitrogen-rich carbon substrate both exhibit exceptional electrocatalytic activity for ORR. Consequently, a conventional liquid zinc-air battery utilizing this material as the air cathode catalyst exhibits a maximum power density of 242.8 mW cm−2, surpassing that of commercial Pt/C. Additionally, DFT calculations further confirm the crucial enhancing influence of Fe 3 N in the Fe-Fe 3 N/3DNC composite on ORR. This research provides valuable insights for the development of ORR electrocatalysts with outstanding efficiency. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • H-BN/TiO 2 nanocomposites were synthesized by sol-gel method under h-BN sheets solution. • H-BN sheets decreased the charge transfer resistance, inhibiting the charge recombination. • H-BN/TiO 2 formed a new bond B O Ti, and it was a strong interaction between h-BN sheets and TiO 2 nanoparticles. • H-BN/TiO 2 nanocomposites shown excellent photocatalytic performance, and good cycle stability. Abstract Hexagonal boron nitride (H-BN)/titania (TiO 2) nanocomposites photocatalysts were synthesized by a facile sol-gel method. The structure was verified by comprehensive analysis from X-ray diffraction, Raman, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscope and transmission electron microscope. The degradation of organic dyes such as rhodamine B (RhB) and methylene blue (MB) under UV light irradiation was used to measure the photocatalytic activity of the h-BN/TiO 2 nanocomposites. The photocatalytic performance and the stability of H-BN/TiO 2 nanocomposites in the degradation of dyes (MB and RhB) significantly outperformed pure TiO 2 nanoparticles. The formed B O Ti bond in H-BN/TiO 2 gave rise to a strong link between h-BN sheets and TiO 2 nanoparticles, and thus the charge transportation rate was improved and the recombination of electrons and holes was suppressed in the photocatalytic processes. The degradation percentage for RhB and MB reached 98% and 92% within 50 min irradiation. The degradation rate (k) of first-order linear value of h-BN/TiO 2 nanocomposites (0.05952 and 0.0498) for RhB and MB degradation was 3.64 and 4.22 times higher than that of pure TiO 2 (0.01637 and 0.0118). The enhanced photocatalytic property of the nanocomposites was attributed to the reduction in charge recombination and the adsorption interaction between organic dyes and h-BN. Consequently, h-BN sheets hold a great promise to enhance the photocatalytic activity of semiconductive materials. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • ZrO 2 coating was deposited on AA7075 using sol-gel process with benzotriazole and cerium nitrate. • Sequence of layers doped with inhibitor was influenced on the corrosion resistance. • The optimum condition of coating was determined. Abstract Aluminium alloys have been used in the aerospace, automotive and military industrial applications. However, these alloys have the tendency to corrode when the contact with corrosive solution. Therefore, there are many trends to protect these alloys to increase the corrosion resistant by applying the coating. In this work, the zirconia coating doped with benzotriazole and cerium nitrate inhibitors was deposited on AL7075 Aluminium alloy. In order to evaluate the effect of inhibitor on the corrosion resistance, the different type of zirconia coatings were studied. Furthermore, the corrosion behavior of coating was investigated by electrochemical impedance spectroscopy (EIS) and polarization test. Finally the results showed that the homogeneous, uniformity and nanostructured of the zirconia coating was formed. Additionally, the zirconia coatings doped with BTA (4-layers contained inhibitor) showed the better corrosion resistant than the composite coating of (2-layer contained inhibitor) and the zirconia coatings (4 layers without benzotriazole). Finally, the analytic hierarchy process (AHP) and Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) methods, depend on the criteria of type coating, inhibitor type and inhibitor concentration were selected. The evaluation of results showed that the zirconia coating doped with BTA (4-layers contained inhibitor) was the best sample. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Eu, Er, Tb, Yb, Ho, La (0.09–0.45 mmol) modified ZnO QDs obtained by sol-gel approach. • Modification of ZnO QDs by RE resulted in increase of photoactivity and decrease of photoluminesce. • ZnO/Er_0.09 showed the highest photocatalytic activity in phenol degradation (90%) • The photocatalytic properties of ZnO/0.09_Er can be related to new Er3+-3d/4f electronic states. • ZnO/La_0.45 showed the highest quantum yield (81%) Abstract A series of novel ZnO quantum dots modified with rare earth metals was successfully prepared by a simple sol-gel approach. The effects of types (Eu, Er, Tb, Yb, Ho, La) and amounts (from 0.09 to 0.45 mmol) of lanthanides on the optical properties, structural characterization and photocatalytic activity of ZnO/RE QDs were systematically investigated. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) with energy dispersive X-ray analysis (EDX) and UV–Vis diffuse reflectance spectroscopy were used to characterize surface properties, while photoluminescence (PL) emission spectroscopy and UV–Vis-driven degradation of phenol in aqueous phase were applied to understand optical and photocatalytic properties. The experiments demonstrated that generally modification of ZnO QDs by lanthanides resulted in increase of photoactivity while photoluminesce decrease at the same moment. The highest photocatalytic activity among all obtained nanomaterials and the lowest photoluminescence quantum yield among ZnO/Er photocatalysts were observed for ZnO QDs modified with 0.09 mmol of erbium. Increased photocatalytic activity has been shown in successive samples: ZnO/0.09_Er > ZnO/0.18_Eu > ZnO/0.09_La > ZnO/0.27_Er > ZnO/0.18_Tb > pristine ZnO QDs. The experimental results were supported by calculations based on density functional theory (DFT) which revealed atomic and electronic structure of Er/La modified ZnO QDs. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Sol-gel derived spinel NiMn 2 O 4 is synthesized in pure phase. • The structural analysis has been carried out using Rietveld refinement. • The dependence of EIS on potential is extensively demonstrated for first time. • NiMn 2 O 4 electrode exhibits maximum specific capacitance of 875 F g−1. • NiMn 2 O 4 electrode shows excellent ASC device performance. Abstract We report the synthesis of porous spinel-structured binary NiMn 2 O 4 metal oxide nanoparticles and their performance as electrode material for supercapacitors. Spherical NiMn 2 O 4 nanoparticles of ∼8 nm average diameter have been synthesized using inexpensive and simple sol-get method, and characterized by X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The electrodes made of this single phase spinel nanoparticles exhibit superior electrochemical performance with excellent rate capability, offering highest specific capacitance value of 875 F g−1 at 2.0 mV s−1 scan rate in 1 M Na 2 SO 4 electrolyte solution. Furthermore, an asymmetric supercapacitor is also assembled and possesses a wide operating voltage window of 1.8 V, exhibiting an energy density of 75.01 W h kg−1 at a power density of 2250.91 W kg−1. The results infer this highly porous binary metal oxide nanostructures are promising candidates for high performance energy storage applications. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the oxidation properties of amorphous aluminum phosphate coating. Aluminum phosphate precursor solution was prepared by a sol–gel process and then applied on AISI 304 stainless steel using dip coating technique. To evaluate the oxidation behavior, samples were placed in an electrical furnace upto 1100 °C for 100 h in air with weight measurements performed at regular ten-hour intervals. Phase composition analysis of the coatings before and after cyclic oxidation process were performed by X-ray diffractometer (XRD). The surface and cross-sectional morphology of the coatings were observed using scanning electron microscopy (SEM) analysis equipped with energy dispersive spectroscopy of characteristic X-rays (EDS). The amorphous-nanocrystalline structure and distribution of nanocrystals in the amorphous matrix were studied by transition electron microscopy (TEM). According to SEM images a uniform, continuous and crack-free coating was achieved. XRD analysis as well as TEM observations showed that the amorphous structure of coating remained unchanged after annealing at 500 °C for 15 min however; an amorphous-nanocrystalline structure was obtained after annealing at 1100 °C for 1 h. Weight change measurements after 100 h oxidation test revealed that the trace of weight gain against oxidation time for both coated and un-coated substrates were parabola in nature and the range of the weight change of the bare substrate was about 30 times greater than that of observed for the aluminum phosphate coating. In general, the results showed that the synthesized amorphous aluminum phosphate is capable of surface protecting of metals/alloys against degradation at harsh environments. [ABSTRACT FROM AUTHOR]

An approach to achieve the transparent thin film transistors (TTFTs) using transparent electrodes such as ITO or FTO for gate, source and drain electrodes (Free-silicon gate electrode). On the other hand, the high-k transparent metal oxides can be used for this purpose in gate dielectric by a low temperature sol-gel technique. Furthermore, not only use of high-k organic materials in gate dielectric reduces the leakage current but also it improves the device flexibility. The organic-inorganic hybrid composites of SiO 2 /TiO 2 -PVP (STP) with different TiO 2 ratios are deposited on PET-ITO substrates (Free-silicon gate electrode) as gate dielectric. The thermal behavior and structural characterization of STP films are done by TGA, XRD and XPS analyses. The AFM analyze of STP films shows that they have very smooth surface. A transparent thin layer of ZnO is used as a transistor channel by sputtering technique. Evaluation on electrical performance of OFETs exhibits that they have high mobility, low threshold voltage and acceptable I on /I off ratio. [ABSTRACT FROM AUTHOR]

In this work, BiFeO 3 thin films were deposited on FTO substrate by inkjet printing through a sol-gel route. The effect of annealing atmosphere (air, N 2 , O 2 , wet air, wet O 2 , wet N 2 ) on the microstructure and surface property of the BiFeO 3 thin films was characterized by XRD and FE-SEM at room temperature. Ferroelectric properties and leakage currents were investigated in detail to understand the link between annealing atmosphere and thin films quality. Pure perovskite phase and dense microstructure can be promised by ink-jet printing and the thickness of the films can be controlled by the number of layers printed. On the other hand, attributed to the pure BiFeO 3 phase and better surface topography, the films annealed in wet air showed the lowest leakage current density and best ferroelectric properties. It was proposed that less Fe 2+ resulted from the annealing process is the key for the better ferroelectric properties. [ABSTRACT FROM AUTHOR]

In this article, we report an ultra-thin shell of MoS 2 (3–7 nm) deposited on Ag nanowires (AgNWs) to form a core-shell hybrid system by the sol-gol method. Since AgNWs is easy to be oxidized, a protection shell is necessary. Compared with commonly used hydrothermal method for MoS 2 , it could produce a more thinner and homogeneous shell with the least 3 nm thickness of MoS 2 shell, which is a breaking-through of making MoS 2 shell based on noble nanoparticles. Results show that the obtained hybrid system has great value on surface-enhanced Raman spectroscopy (SERS) due to surface plasmon resonance (SPR) effect of Ag nanowires. Ultra-thin MoS 2 shell was suitable for protecting AgNWs and simultaneously had excellent SERS signature, and this effect was rare for MoS 2 shells. By decreasing the thickness of MoS 2 film from 7 to 3 nm, the intensity of SERS signal could be enhanced. It was observed that the microstructure of this AgNWs@MoS 2 system consist of crystal AgNWs surrounded by crystal MoS 2 . AgNWs@MoS 2 showed excellent SERS effect with Rhodamine 6G (R6G) and N719 dyes, the detection limit could reach to 10 −5 M. Finally for comparison, local electromagnetic field enhancement of AgNWs@SiO 2 was also simulated to indicate AgNWs@MoS 2 better. [ABSTRACT FROM AUTHOR]

Ce 3+ and Tb 3+ -doped silico-phosphate films were obtained by using the sol-gel method, followed by the spin-coating deposition on silicon substrate. The homogeneity of the films was investigated by the conoscopy method. It was observed that the analysed films are isotropic but relatively inhomogeneous due to the specificity of the deposition technique. The morphology of the sol-gel films was investigated by Scanning Electron Microscopy and Atomic Force Microscopy. The elemental composition was determined by Energy Dispersive X-ray analysis. The magneto-optical investigations evidenced the capability of Ce and Tb-doped films of less than 2 µm thickness to produce measurable Kerr rotations of 1 mdeg/T and 0.28 mdeg/T, respectively. [ABSTRACT FROM AUTHOR]

Under in situ UV illumination, some materials present evolution of their opto-electronic properties that can be monitored by spectroscopy. We present here a mathematical method which can be applied to spectroscopic measurements when an evolving set of data is recorded: the vectorial method. The investigations and quantifications are performed by Infrared spectroscopy and XPS on organic-inorganic thin films prepared by sol-gel. The inorganic part of these hybrid thin films contains Ti oxide-network based whereas the organic part is composed of N,N-dimethylformamide and its hydrolysis products. Under UV illumination, those films exhibit intermediate bandgap behavior due to the photoreduction of Ti(IV) in Ti(III). The role of the solvent in the thin film is underlined during the process of photoreduction together with an understanding of the condensation of the Ti oxide-based network, as these evolutions are critical for the opto-electronic properties of those thin films. [ABSTRACT FROM AUTHOR]

The influence of Fe and Ni (1 wt.%) doping on the wettability and photocatalytic activity of sol–gel derived SnO 2 films is reported. X-ray diffraction studies revealed the presence of tetragonal phase for both pure and doped SnO 2 thin films. The crystallite size was of the order of 8 nm indicating the nanocrystalline nature of the films. The pure SnO 2 films which were hydrophilic with a contact angle of 11.8° showed increase in contact angle with doping (38.7° for Fe and 48.6° for Ni). This is accompanied by decrease in surface energy and root mean square roughness, with doping of SnO 2 film. In order to further increase the water contact angle, the film surfaces were modified using a layer of stearic acid. As a consequence, the water contact angles increased to 108°, 110° and 111° for the pure, Fe and Ni doped SnO 2 films respectively, rendering them hydrophobic. Significantly, the unmodified surfaces that did not exhibit any change under UV irradiation showed photoinduced hydrophilicity on modification with stearic acid. There was a red-shift in the optical band gap of SnO 2 films from 3.8 to 3.5 eV with doping, indicating the possibility of dopant controlled photocatalytic activity. This was confirmed by observing the photocatalytic degradation of an aqueous solution of methylene blue under UV irradiation. There was, indeed, significant improvement in the photocatalytic efficiency of the metal doped SnO 2 thin film in comparison to undoped film. The current work, thus, demonstrates a simple method to chemically engineer the wettability and photocatalytic activity of SnO 2 thin film surfaces. [ABSTRACT FROM AUTHOR]

The bad resistance to SO 2 was still the primary defect of Mn/TiO 2 catalyst for selective catalytic reduction of NOx with NH 3 . To address that, a series of MnNb/TiO 2 catalyst samples with different Nb/Mn molar ratio were prepared by sol-gel method and used in NH 3 -SCR reaction. Experimental results indicated that the MnNb/TiO 2 -0.12 catalyst exhibited outstanding SCR activity and SO 2 resistance. The introduction of Nb into Mn/TiO 2 catalyst could promote the formation of more Mn 4+ and chemisorbed oxygen species on its surface, along with the generation of more NO 2 . In addition, the doping of Nb on Mn/TiO 2 catalyst could remarkably intensify its surface acidity. All these factors were conducive to improving the SCR performance of MnNb/TiO 2 -0.12 catalyst. The results of DRIFT study revealed that the NH 3 -SCR reaction over MnNb/TiO 2 -0.12 catalyst took place through both Eley–Rideal and Langmuir-Hinshelwood pathways, in which Eley–Rideal pathway was predominant. In the presence of SO 2 , it seemed that the NH 3 -SCR reaction over Mn/TiO 2 and MnNb/TiO 2 -0.12 mainly happened between adsorbed NO 2 and gaseous NH 3 (Eley–Rideal mechanism), thus the formation of more NO 2 over MnNb/TiO 2 -0.12 catalyst should mainly account for its super SO 2 tolerance. [ABSTRACT FROM AUTHOR]

In current study, various pore-forming agents were employed for the synthesis of Fe-W-Ti catalysts via sol-gel one-pot approach, and the catalytic performance was investigated for selective catalytic reduction of NO x by ammonia (NH 3 -SCR). Among all the catalysts, Fe 0.2 W 0.2 Ti(U 0.03 , urea-modification) catalyst exhibited more than 95% NO x conversion in range of 240–420 °C, and excellent performance of resistance to SO 2 and H 2 O was observed with a slight decline of NO x conversion to 92%. The characterization results revealed that urea-modified catalyst possessed low crystallinity of TiO 2 with particle size of 3.8 nm and the dispersion of Fe-W species was increased significantly, which could be ascribed to the high specific surface area (144.92 m 2 /g) and superior porous structure. The sufficient strong acid, the remarkable reducibility and the increase in the ratio of divalent iron & adsorbed oxygen may be responsible for the excellent catalytic activity. Moreover, a dramatic drop in the specific surface area and surface acidity of the hydrothermal aged catalyst was observed, and the active species also became agglomerated with FeWO 4 solid solution. [ABSTRACT FROM AUTHOR]

In this study, a novel micro-nano hierarchical fluorinated Ag/SiO 2 structure having both superhydrophobic and superoleophobic properties is presented. SiO 2 layers with microscale roughness were fabricated using a combination of sol-gel and electrospraying processes. Nanoparticles of silver were deposited on SiO 2 using a UV reduction method; subsequent fluorination treatment resulted in micro-nano hierarchical fluorinated Ag/SiO 2 layers. The micro-nano hierarchical fluorinated Ag/SiO 2 layers have outstanding repellency towards different liquids including water, with a water contact angle of 170° and sliding angle of 1°. This demonstrated the excellent superhydrophobic nature of the micro-nano hierarchical structures. Long-term durability, durability of ex-situ and in-situ fluorinated Ag/SiO 2 layers in harsh environments, and ultraviolet resistance of the superhydrophobic fluorinated Ag/SiO 2 layers were studied. Thermal stability studies showed that the superhydrophobic properties were retained even at 400 °C for 10 h, indicating the good thermal resistance of the fluorinated Ag/SiO 2 . Finally, the fluorinated Ag/SiO 2 structure showed outstanding superoleophobicity (contact angle of 158°) towards mineral oil, which demonstrates the superamphiphobic nature of the micro-nano hierarchical fluorinated Ag/SiO 2 structures. Such superamphiphobic fluorinated Ag/SiO 2 layers can be used to produce self-cleanable, anti-fogging, anti-bacterial, anti-reflection, and anti-icing surfaces. [ABSTRACT FROM AUTHOR]

In this study, a new novel composite photocatalyst of NaYF 4 :(Gd, Si)/TiO 2 phosphor has been synthesized by two step method of solution combustion and sol-gel. The photocatalyst powders were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), UV–vis spectroscopy and photoluminescence (PL) spectroscopy. Raman spectroscopy confirmed the anatase TiO 2 phase which remarkably increased with existence of yttrium silicate compounds between 800 cm −1 and 900 cm −1 . Double-addition of Gd 3+ -Si 4+ ions in NaYF 4 host introduced sub-energy band levels with intense absorption in the ultraviolet (UV) light region. Photocatalytic activity was examined by exposing methylene blue (MB) solutions mixed with photocatalyst powders to 254 nm UV-C fluorescent lamp and 200 W visible lights. The UV and visible photocatalytic reactivity of the NaYF 4 :(Gd, 1% Si)/TiO 2 phosphor composites showed enhanced MB degradation efficiency. The coating of NaYF 4 :(Gd, 1% Si) phosphor with TiO 2 nanoparticles creates energy band bending at the phosphor/TiO 2 interfaces. Thus, these composites exhibited enhanced absorption of UV/visible light and the separation of electron and hole pairs for efficient photocatalysis. [ABSTRACT FROM AUTHOR]

In this work, high-performance inverted planar perovskite solar cells (PSCs) using sol-gel processed Y-doped NiO thin films as hole transport layer (HTL) were demonstrated. Y-doped NiO thin films containing different Y doping concentrations were successfully prepared through a simple sol-gel process. The Y doping could significantly improve the electrical conductivity of NiO thin film, and the photovoltaic performance of Y-doped NiO HTL-based PSC devices outperformed that of the pristine NiO HTL-based device. Notably, the PSC using a 5%Y-NiO HTL exhibited the champion performance with an open-circuit voltage ( V oc ) of 1.00 V, a short circuit current density ( J sc ) of 23.82 mA cm −2 , a fill factor ( FF ) of 68% and a power conversion efficiency ( PCE ) of 16.31%, resulting in a 27.62% enhancement in PCE in comparison with the NiO device. The enhanced performance of the Y-doped NiO device could be attributed to the improved hole mobility, the high quality compact active layer morphology, the more efficient charge extraction from perovskite absorber as well as the lower recombination probability of charge carriers. Thus, this work provides a simple and effective approach to improve the electrical conductivity of p-type NiO thin films for use as a promising HTL in high performance PSCs. [ABSTRACT FROM AUTHOR]

High-performance inkjet-printed nickel oxide thin-film transistors (TFTs) with Al 2 O 3 high-k dielectric have been fabricated using a sol-gel precursor ink. The “coffee ring” effect during the printing process was facilely restrained by modifying the viscosity of the ink to control the outward capillary flow. The impacts on the device performance was studied in detail in consideration of annealing temperature of the nickel oxide film and the properties of dielectric layer. The optimized switching ability of the device were achieved at an annealing temperature of 280 °C on a 50-nm-thick Al 2 O 3 dielectric layer, with a hole mobility of 0.78 cm 2 /V·s, threshold voltage of −0.6 V and on/off current ratio of 5.3 × 10 4 . The as-printed p-type oxide TFTs show potential application in low-cost, large-area complementary electronic devices. [ABSTRACT FROM AUTHOR]

This research has focused on the effect of graphene oxide (GO) nano-fillers embedded in the sol-gel based silane coating on the corrosion protection and adhesion properties of the epoxy coating applied on the steel substrate pre-treated by silane coatings. For this purpose, a mixture of Methyltriethoxysilane (MTES) and Tetraethylorthosilicate (TEOS) silane precursors was used for preparation of composite matrix and the GO nanosheets, which are covalently functionalized with 3-(Triethoxysilyl)propyl isocyanate (TEPI, IGO nano-fillers) and 3-aminopropyltriethoxysilane (APTES, AGO nano-fillers), were used as filler. The GO, AGO and IGO nanosheets were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), UV–Visible analysis and field emission-scanning electron microscopy techniques. The performance of the silane/epoxy coatings was investigated by pull-off adhesion, cathodic delamination, salt spray and electrochemical impedance spectroscopy (EIS) tests. Results revealed that AGO and IGO nano-fillers significantly improved the corrosion resistance and adhesion properties of the top epoxy coating due to better compatibility with silane matrix, excellent barrier properties and the formation of covalent bonds with the top epoxy coating. [ABSTRACT FROM AUTHOR]

The microstructure and optical properties of TiO 2 thin films, prepared by the sol-gel dip coating technique on glass substrates, were inspected. After deposition, the films were annealed at several temperatures in the 400–850 °C range and the resulting nanostructured films were studied by different techniques showing that their structural and optical characteristics evolved significantly with the increased annealing temperature. The analysis of these results by the assumption of the Tauc Lorenz model and the use of Wemple–DiDomenico equation leads to a correlation between microstructural aspects and optical characteristics of the films. Thus, crystallization processes (nucleation, growth and phase transformation) and the evolution of films texture and thickness with increasing annealing temperatures are related with the variation of the refractive index, average gap and extinction coefficient during annealing. Finally, the free-carrier concentration in the films, estimated from the Spitzer–Fan model, ranged from 1.44 × 10 19  cm −3 to 3.07 × 10 19  cm −3 with the changing annealing temperature, which is in agreement with those obtained in similar anatase thin films from electrical measurement techniques. [ABSTRACT FROM AUTHOR]

Sol-gel derived noble-metal-silica nanocomposites are very useful in many applications. Due to relatively low price, higher conductivity, and higher chemical stability of silver (Ag) compared with copper (Cu), Ag-silica has gained much more research interest. However, it remains a significant challenge to realize high loading of Ag content in sol-gel Ag-silica composite with high structural controllability and nanoparticles’ dispersity. Different from previous works by using multifunctional silicon alkoxide to anchor metal ions, here we report the synthesis of Ag-silica nanocomposite with high loading of Ag nanoparticles by employing acetonitrile bi-functionally as solvent and metal ions stabilizer. The electrical conductivity of the Ag-silica nanocomposite reached higher than 6800 S/cm. In addition, the Ag-silica nanocomposite could simultaneously possess high electrical conductivity and positive conductivity-temperature coefficient by properly controlling the loading content of Ag. Such behavior is potentially advantageous for high-temperature devices (like phosphoric acid fuel cells) and inhibiting the thermal-induced increase of devices’ internal resistance. The strategy proposed here is also compatible with block-copolymer directed self-assembly of mesoporous material, spin-coating of film and electrospinning of nanofiber, making it more charming in various practical applications. [ABSTRACT FROM AUTHOR]

Herein, we demonstrated the simultaneous formation of multi-component heterojunction consisting graphitic carbon nitride (g-C 3 N 4 ) and C, N co-doped anatase/rutile mixed phase by using facile sol-gel assisted heat treatment. The evolution of core-shell nanostructures heterojunction formation was elucidated by varying the temperature of heat treatment from 300 °C to 600 °C. Homogeneous heterojunction formation between g-C 3 N 4 and anatase/rutile mixed phase was observed in gT400 with C and N doping into TiO 2 lattice by O substitution. The core-shell nanoarchitectures between g-C 3 N 4 as shell, and anatase/rutile mixed phase as core with C and N atoms are doped at the interstitial positions of TiO 2 lattice was observed in gT500. The result indicated that core-shell nanoarchitectures photocatalyst (gT500) prepared at 500 ◦C exhibited the highest photocatalytic activity in the degradation of methyl orange under visible light irradiation. Meanwhile, the possible mechanisms of charge generation, migration, action species and reaction that probably occur at the gT500 sample were also proposed. The photodegradation results of gT500 correlated completely with the results of the PEC and photoluminescence analysis, which directly evidenced improved charge separation and migration as the crucial parameters governing photocatalysis. It is worthy to note that, the simultaneous formation of multicomponent heterojunction with core-shell structure provided an enormous impact in designing highly active photocatalyst with superior interfacial charge transfer. [ABSTRACT FROM AUTHOR]

Benzene is currently recognized as one of the most toxic contaminants. Our previously published study revealed that BiVO 4 /TiO 2 is an excellent photocatalyst toward the degradation of benzene. Herein, BiVO 4 /TiO 2 has been synthesized via a sol-gel method and a facile hydrothermal route by adjusting the precursor hydrolysis rate with the use of different acids (CH 3 COOH, HNO 3 and H 2 SO 4 ). The influence of these acids on the physicochemical characteristics and photocatalytic performance is discussed in detail. X-ray diffraction and N 2 sorption analyses confirm that acid has an important effect on the crystalline composition and BET specific surface area. BiVO 4 /TiO 2 synthesized in CH 3 COOH has better photocatalytic activity for the degradation of gaseous benzene than that in HNO 3 and H 2 SO 4 under visible light irradiation. Results of XPS measurement demonstrate that the hydroxyl group in BiVO 4 /TiO 2 -CH 3 COOH is more abundant than that in BiVO 4 /TiO 2 -HNO 3 and BiVO 4 /TiO 2 -H 2 SO 4 . The photocurrent signal is investigated by electrochemical measurement, which indicates that more effective separation of photogenerated carriers occurs in the BiVO 4 /TiO 2 /CH 3 COOH system. It is hoped that our work can offer valuable information on the design of TiO 2 composites with enhanced properties. [ABSTRACT FROM AUTHOR]

In this work, a novel kind of magnetic, core-shell structured and surface molecularly imprinted polymers (MMIPs) for the recognition of salicylic acid (SA) was facilely synthesized through a surface imprinting and sol-gel polymerization approach. The as-synthesized MMIPs exhibit uniform core-shell structure and favorable magnetic properties with a saturation magnetization of 22.8 emu g −1 . The binding experiments demonstrated that MMIPs possessed high binding and specific recognition capacity, as well as fast binding kinetics and phase separation rate. The maximum binding capacity of MMIPs is around 36.8 mg g −1 , nearly 6 times that of the magnetic non-imprinted polymers (MNIPs). Moreover, the selectivity experiments show that all the relative selectivity coefficients towards SA over its structure analogs are higher than 18, further indicating the markedly enhanced binding selectivity of MMIPs. Furthermore, the MMIPs were successfully applied for the determination of SA in environmental water samples with the recovery rates ranging from 94.0 to 108.0 %. This strategy may provide a versatile approach for the fabrication of well-defined molecularly imprinted polymers on nanomaterials for the analysis of complicated matrixes. [ABSTRACT FROM AUTHOR]

This is the first time sol-gel technology is used in the treatment of hemp shiv to develop sustainable thermal insulation building materials. The impact on the hydrophobicity of hemp shiv by depositing functionalised sol-gel coatings using hexadecyltrimethoxysilane (HDTMS) has been investigated. Bio-based materials have tendency to absorb large amounts of water due to their hydrophilic nature and highly porous structure. In this work, the influence of catalysts, solvent dilution and HDTMS loading in the silica sols on the hydrophobicity of hemp shiv surface has been reported. The hydrophobicity of sol-gel coated hemp shiv increased significantly when using acid catalysed sols which provided water contact angles of up to 118° at 1% HDTMS loading. Ethanol diluted sol-gel coatings enhanced the surface roughness of the hemp shiv by 36% as observed under 3D optical profilometer. The XPS results revealed that the surface chemical composition of the hemp shiv was altered by the sol-gel coating, blocking the hydroxyl sites responsible for hydrophilicity. [ABSTRACT FROM AUTHOR]

Two kinds of mesoporous ceria-zirconia-alumina supports were prepared by a single-step epoxide-driven sol-gel method (SGCZA) and by a co-precipitation method (PCZA). Palladium catalysts supported on these materials were then prepared by a wet impregnation method (Pd/SGCZA and Pd/PCZA). The prepared catalysts were applied to the CO oxidation reaction before and after sulfur aging. XRD and N 2 adsorption-desorption analyses revealed that these two catalysts retained different physicochemical properties. Pd/SGCZA had higher surface area and larger pore volume than Pd/PCZA before and after sulfur aging. TPR (Temperature-programmed reduction), CO chemisorption, FT-IR, and XPS analyses showed that the catalysts were differently influenced by sulfur species. Pd/SGCZA formed less sulfate and retained higher palladium dispersion than Pd/PCZA after sulfur aging. In the CO oxidation, Pd/PCZA showed better activity than Pd/SGCZA before sulfur aging. However, Pd/SGCZA showed higher CO conversion than Pd/PCZA after sulfur aging. We concluded that Pd/SGCZA was less poisoned by sulfur species than Pd/PCZA. [ABSTRACT FROM AUTHOR]