Sol-gel Research Articles

Effectiveness Evaluation of Silicone Oil Emulsion In Situ Polymerization for Dehydration of Waterlogged Wooden Artifacts

Organosilicon materials have shown potential as dehydration agents for waterlogged wooden artifacts. These materials can polymerize under normal conditions to form polymers with favorable mechanical strength, antibacterial properties, and aging resistance. However, the insolubility of most organosilicon hindered their penetration into waterlogged wood, which may lead to an unwanted cracking. This study aimed to evaluate the effectiveness of polydimethylsiloxane (PDMS) and hydroxy-terminated polydimethylsiloxane (PDMS-OH) with low viscosity and moderate reactivity for dehydrating waterlogged wooden artifacts from the Nanhai No.1 shipwreck. Four surfactants ((3–aminopropyl) triethoxysilane (APTES), alkyl polyoxyethylene ether (APEO), tri-methylstearylammonium chloride (STAC), and fatty alcohol polyoxyethylene ether (AEO)) and cosurfactant were employed to transform the two kinds of water-repellent silicone oils into eight groups of highly permeable oil-in-water (O/W) emulsions. Under the catalysis of a neutral catalyst, in situ polymerization occurred within the wood cells. Group P2-2 formulated with PDMS-OH and APEO showed the best efficiency in maintaining the dimensions of the wood during dehydration. The dehydrated wood exhibited a natural color and texture with a minimal volume shrinkage rate of 1.89%. The resulting polymer adhered uniformly to the cell walls, effectively reinforcing the wood cell structure. The weight percent gain of the wood was only 218%, and the pores of the cell lumen were well maintained for future retreatment. This method effectively controlled the sol–gel reaction process of the organosilicon and prevented damage to the wooden artifact during the dehydration process. Moreover, the dehydrated wood samples only experienced a low weight gain of 17% at 95% relative humidity (RH), indicating their great environmental stability.

Enhanced Thermal Conductivity and Stability of Hydrated Salt Phase Change Microcapsules With GO/SiO2 Hybrid Shell for Battery Thermal Management

AbstractHerein, the synthesis of a novel microencapsulated phase change material via a sol–gel method is presented, featuring disodium hydrogen phosphate dodecahydrate as the core and a SiO2/graphene oxide composite as the shell. The morphology and core–shell microstructure of the synthesized microcapsules are characterized using scanning electron microscopy. The phase change performance and thermal stability are evaluated by differential scanning calorimetry and a high/low temperature test chamber, respectively. Energy dispersive X‐ray spectroscopy and Fourier transform infrared spectroscopy are employed to determine the chemical composition of the microcapsules. The findings reveal that the MEPCM exhibited a high melting enthalpy of 174.3 J g−1. The degree of supercooling is reduced by 2.1 °C, and after 600 thermal cycles, the phase change enthalpy of the microcapsules showed a minor decrease of ≈6.0%. Notably, the thermal conductivity of the microcapsules is significantly enhanced, increasing by up to 51.8%. When integrated into the thermal management systems of lithium‐ion batteries, the MEPCM effectively maintained the battery temperature below 46 °C under a 3 C charging rate. In summary, these results suggest that the hydrated salt microcapsule with its hybrid silica and graphene oxide shell is a promising material for the thermal management of lithium‐ion batteries.

Comprehensive Characterization of Bi1.34Fe0.66Nb1.34O6.35 Ceramics: Structural, Morphological, Electrical, and Magnetic Properties

Recent research in solid-state physics and materials engineering focuses on the development of new dielectric materials, with bismuth-based pyrochlores being already extensively applied in communications technology for their excellent dielectric properties and relatively low sintering temperatures. Herein, the structural, morphological, electrical, and magnetic properties of Bi1.34Fe0.66Nb1.34O6.35 ceramic, prepared by the sol–gel method and sintered at 500 °C, are investigated. The Rietveld refinement of the XRD pattern showed a cubic phase belonging to the space group Fd-3m and a crystallite size of 42 nm. Transmission electron microscopy further confirmed the crystallite size and the homogeneous distribution of Bi, Fe, Nb, and O elements, as evidenced by high-angle annular dark field imaging and STEM-EDX mapping. The morphology of the sample, assessed by scanning electron microscopy, is characterized by submicron-sized spherical particles. Dielectric spectroscopic studies revealed that the dielectric properties, strongly influenced by frequency and temperature, indicate the material’s potential for energy storage due to lower dielectric loss compared to the dielectric constant. The observed relaxation phenomena, confirmed through variations in dielectric loss and loss tangent, highlight the influence of grain boundaries and temperature on electron hopping and charge carrier dynamics. Using SQUID magnetometry, we identified two distinct magnetic phases. The primary phase, corresponding to the Bi1.34Fe0.66Nb1.34O6.35 ceramic, exhibits an antiferromagnetic behavior below its Néel temperature at around 8.8 K. A secondary high-Curie temperature ferrimagnetic phase, likely vestigial maghemite and/or magnetite, was also detected, indicating an estimated fraction below 0.02 wt.%.

Sol-gel synthesis and research of inorganic compounds, hybrid functional materials and disperse systems

The results are summarised of the Seventh International Conference of CIS countries “Sol-gel synthesis and research of inorganic compounds, hybrid functional materials and disperse systems “Sol-gel 2023”, the key reports are discussed within the scientific sections: Theoretical aspects of sol-gel process; Films, coatings and membranes obtained using sol-gel technology; Hybrid organic-inorganic sol-gel materials; Xerogels, glasses and bulk ceramic materials synthesized by sol-gel method; Nano- and microstructured materials, nanotechnology; Methods of research of structure and properties of materials obtained using sol-gel synthesis.

The enhanced SO2 resistance of Fe-Ti catalyst by W/SO42− co-modification for NH3-SCR: A combined experimental and DFT study

It remains a great challenge to improve the low-temperature SO2 resistance of catalysts applied for selective catalytic reduction of NOx with NH3 (NH3-SCR). This work develops an outstanding SO2-tolerant Fe-Ti (FT) catalyst by W/SO42− co-modification via a sol–gel method using Fe(NO3)3·9H2O, tetrabutyl titanate, ammonium tungstate and thiourea as raw materials. The physicochemical characterizations, in-situ diffuse reflectance infrared Fourier transform (DRIFT) measurements and density functional theory (DFT) calculations were combined to reveal the underlying mechanisms. Although W doping can effectively enhance the surface acidity, NH3 adsorption on Lewis acid sites can still be restrained by competitive adsorption of SO2, whereas SO42− modification can enhance the adsorption stability of NH3 without being affected by SO2. Simultaneously, the NO adsorption ability on Fe sites can be significantly enhanced by W/SO42− co-modification. Furthermore, the W doping or SO42− modification can induce conversion of Fe3+ to Fe2+ to affect the redox property of Fe species. A proper amount of Fe2+ suppressed the oxidizability of FT catalyst to inhibit NH3 overoxidation to enhance N2 selectivity, and created more oxygen vacancies to generate larger amount of chemisorbed oxygen to facilitate NH3 dehydrogenation and NO oxidation. More importantly, the inhibition effect of SO2 adsorption on Fe sites was strengthened by W/SO42− co-modification. Consequently, the W/SO42− co-modified FT catalyst exhibited high activity with >90 % of NO conversion and >95 % of N2 selectivity within a broad window of 275–450 °C and possessed superior SO2 + H2O tolerance at 275 °C.

Spectroscopic investigation of Pr3+ doped ZnS nanoparticle in silica glass matrix prepared by sol–gel method

Spectroscopic investigation of Pr3+ doped ZnS nanoparticle in silica glass matrix prepared by sol–gel method

Development of Functionalized Polylactide Thin Films Using Poly(methylhydrogenosiloxane) Sol-Gel Process with Improved Antifouling Properties.

Biobased polylactide (PLA) films were modified with low reticulate polysiloxane gel acting as a scalable platform for the hydrophilization of polymeric film surface. The PLA thin film was first coated with poly(methylhydrogenosiloxane) (PMHS) by the sol-gel transition via the condensation of diethoxymethylsilane (DH) and triethoxysilane (TH) using trifluoromethanesulfonic acid as a catalyst. Then, hydrosilylation of Si-H bonds in the presence of Karstedt's catalyst allowed the covalent grafting of hydrophilic alkene-containing molecules, i.e., triethylene glycol monomethyl allyl (TEGMEA) and a new zwitterionic allylcarboxybetaine (ACB) synthesized for the first time by the quaternization of dimethyl allyl amine (DMAA) with β-propiolactone. PMHS coating on the PLA film was evidenced by Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The observation by atomic force microscopy (AFM) revealed a homogeneous coating with low roughness (RMS = 0.29 nm). The hydrophilicity of functionalized PLA films was determined by water contact angle (WCA) measurements using the captive bubble method. A large increase in wettability properties was observed for both grafting with TEGMEA (WCA = 38°) and ACB (WCA = 42°) in comparison with the native PLA film (WCA = 80°). Moreover, the biocompatibility and antifouling efficiency of functionalized PLA films were evaluated by protein adsorption, bacterial adhesion, and cytotoxicity tests. The results indicate that the grafting of the two types of hydrophilic compounds does not affect the biocompatibility of PLA while significantly reducing protein adsorption and bacterial adhesion, thus showing the great potential of this surface functionalization strategy for applications in the medical field.

Time-Dependent Resistance of Sol–Gel HfO2 Films to In Situ High-Temperature Laser Damage

Laser damage in films under long-term high-temperature conditions is a significant concern for advancing laser applications. This study focused on HfO2 films prepared using the sol–gel method with HfCl4 as a precursor. It examined the effects of temperature on various properties of the films, including their optical properties, microstructure, surface morphology, absorption, and laser-induced damage threshold (LIDT). The prepared film demonstrated desirable characteristics at the high temperature of 423 K, such as high transmittance, low absorption, and high LIDT. As the duration of its high-temperature exposure increased, the LIDT of the films gradually decreased. An intriguing finding was that the film’s LIDT exhibited an exponential decay pattern with prolonged heating time. This observation could be attributed to the power-law increase in defects on both the internal and surface areas of the film as the duration of high-temperature exposure lengthened. Moreover, even after a 15-day heating period at 423 K, the film maintained an LIDT of 12.9 J/cm2, indicating its potential applicability in practical high-temperature environments. This study provided a general pattern and a universal formula for understanding the laser damage of sol–gel films at high temperatures over time. Furthermore, it opened possibilities for future developments of laser films suitable for extreme environments.

Preparation and Properties of Flexible Phenolic Silicone Hybrid Aerogels for Thermal Insulation

In order to prepare flexible thermal protection aerogel materials, using dimethyldimethoxysilane (DMDMS) and methyltrimethoxysilane (MTMS) as co-precursors, isocyanate-propyltrimethoxysilane (CFS-006) was added to the co-precursor as a coupling agent, and resorcinol and formaldehyde were added to the sol solution to prepare a phenolic silicone hybrid aerogel (FAS) by the sol–gel method. The prepared FAS aerogel had no phase separation problem, the density was only 0.118 g/cm3, the hydrophobic angle reached 155.3°, and it had certain flexibility. It could be compressed to 70% and still be restored to its original state. The FAS aerogel also had a low thermal conductivity of 0.0318 W/(m·K) and good high temperature insulation. The introduction of phenolic groups improved thermal stability; Tmax increased to 643.7 °C, and the residual carbon rate was 24.5%. This work has positive significance for the future combination of aerogels and textiles in the preparation of firefighting protective clothing.

A study on the influence of metal Ag, Cu, and Fe doping on the morphological, structural, and photocatalytic activity of TiO2 nanostructures

Metal-doped TiO2 nanoparticles (NPs) were elaborated by a sol–gel method using n-butoxide of titanium (IV) as precursors. The resulting NPs were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, and FTIR analysis. The SEM study shows the formation of a spheres-like structure. The EDX analysis proves the presence of Ag, Fe, and Cu on the doped TiO2 NPs. XRD and Raman spectroscopy analysis show that the doping inhibited the phase transformation and stabilized the anatase phase. The photocatalytic activity of prepared TiO2 NPs was evaluated in methylene blue (MB) photodegradation under UV irradiation. The results reveal that the doped TiO2 NPs were more efficient than undoped TiO2 NPs in the degradation of MB. The Cu-doped TiO2 NPs were found to be more efficient in this reaction with a degradation efficiency of about 92.31 % and a kinetic rate constant of about 10−2 min−1. The studies of the reactive species show that the holes are the main reactive species responsible for the photocatalytic oxidation of MB. Furthermore, the reusability studies showed that the photocatalysts are globally stable for the photodegradation of MB.

In-situ sol-gel process for the formulation of Bis-GMA/TEGDMA/silica dental nanocomposite

A novel dental composite based on Bis-GMA/TEGDMA resin incorporating silica nanoparticles was developed using an innovative in situ sol-gel process. This method ensures a homogeneous dispersion of fillers, effectively preventing their agglomeration during preparation. It results in an interpenetrating network in which polymer chains and silica particles are intimately mixed, thereby enhancing the structural and mechanical properties and minimizing the volumetric shrinkage of the dental restorative material.The formation of organic and inorganic network was confirmed by infrared spectroscopy. The in situ synthesis enabled uniform dispersion of silica nanoparticles within the material as evidenced by transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy.The results showed that the prepared composite containing 50 wt% fillers achieved hardness, modulus of elasticity, compressive strength and flexural strength values of 72 HV, 10 GPa, 240 MPa, and 110 MPa, respectively. These properties are comparable to those of the commercial “Nt Premium” composite containing 75 % preformed silica nanoparticles, which has hardness, modulus of elasticity, compressive strength and flexural strength values of 68 HV, 10 GPa, 220 MPa and 95 MPa, respectively. Additionally, the study revealed a significantly reduced volumetric shrinkage of 0.5 % for our composite, compared with over 2.2 % for Nt Premium. This groundbreaking approach holds substantial promise for developing advanced dental materials, offering superior performance and enhanced longevity in clinical applications.

Cu-doped calcium phosphate supraparticles for bone tissue regeneration.

Calcium phosphate (CaP) minerals have shown great promise as bone replacement materials due to their similarity to the mineral phase of natural bone. In addition to biocompatibility and osseointegration, the prevention of infection is crucial, especially due to the high concern of antibiotic resistance. In this context, a controlled drug release as well as biodegradation are important features which depend on the porosity of CaP. An increase in porosity can be achieved by using nanoparticles (NPs), which can be processed to supraparticles, combining the properties of nano- and micromaterials. In this study, Cu-doped CaP supraparticles were prepared to improve the bone substitute properties while providing antibacterial effects. In this context, a modified sol-gel process was used for the synthesis of CaP NPs, where a Ca/P molar ratio of 1.10 resulted in the formation of crystalline β-tricalcium phosphate (β-TCP) after calcination at 1000 °C. In the next step, CaP NPs with Cu2+ (0.5-15.0 wt%) were processed into supraparticles by a spray drying method. Cu release experiments of the different Cu-doped CaP supraparticles demonstrated a long-term sustained release over 14 days. The antibacterial properties of the supraparticles were determined against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, where complete antibacterial inhibition was achieved using a Cu concentration of 5.0 wt%. In addition, cell viability assays of the different CaP supraparticles with human telomerase-immortalized mesenchymal stromal cells (hMSC-TERT) exhibited high biocompatibility with particle concentrations of 0.01 mg mL-1 over 72 hours.

Metals doping effect of perovskite–type La-Mn oxides for NH3-SCR reaction at low temperature

Doping of perovskites with the heteroatoms has emerged as an additional lever, a dimension beyond structural perfection and compositional distinction, for the alteration of many properties of perovskites. In this work, a series of different metals were doped via citric acid sol–gel method to investigate their influences on the structure and catalytic performance of La-Mn perovskite oxides for NH3-SCR reaction. It is found that Zr doped La-Mn oxides (LMZr) displays better low-temperature deNOx performance (T90 = 118 °C) than other metal doped catalysts. Such a result is mainly attributed to the increase of Lewis acid sites, surface Mn4+ and adsorbed oxygen species. Besides, La-Mn perovskite doped with Sr, Ce, Y and Al can also obviously improve low-temperature deNOx activity and N2 selectivity. These doped metals mainly change the electron transfer between different cations, thus changing the valence distribution of Mn on the surface, meanwhile, metal doping changes the crystalline size of the catalysts, thereby affecting the adsorption and activation of NH3 and O2 involved in the removal of NO. Although other metal doping alters the tolerance of the La-Mn catalyst to SO2 and/or H2O, SO2 is inevitably oxidized to S6+ and deposits on the catalyst surface. Zr or Ce doping significantly enhances the tolerance to SO2 and/or H2O, but they have a different mechanism. Zr reduces the deposition rate of sulfate while Ce reacts with SO2 to form Ce2(SOx)3 to protect Mn active species. This paper highlights the importance of Lewis acid, Mn4+ content and adsorbed oxygen in the NH3-SCR reaction.

Removal of Methylene Blue from Aqueous Solution through Adsorption and Heterogeneous Fenton Reaction using Iron Oxides Produced by Different Methods

Direct discharge of industrial wastewater containing dyes into water bodies has contributed to the scarcity of drinking water. As environmental legislation becomes stricter, it is increasingly important to develop efficient methods for wastewater treatment. Traditional methods are commonly costly and have limited efficiency. This study aimed to prepare iron oxides via different synthetic routes and evaluate the effect of synthesis method on the efficiency of these materials as adsorbents and heterogeneous Fenton catalysts for the removal of methylene blue from aqueous solution. Iron oxides were synthesized by non-hydrolytic sol–gel (NHSG) and co-precipitation (CP) methods, followed by hydrothermal treatment for different times. CP oxides demonstrated high efficiency in dye adsorption, particularly the sample subjected to hydrothermal treatment for 6 h (CP-R6). This sample achieved 94.04% removal in 120 min. NHSG materials, by contrast, were less effective. The CP series of materials showed superior catalytic performance in heterogeneous Fenton experiments, with CP-R6 reaching 98.79% decolorization in 240 min. X-ray diffraction analysis indicated that iron oxides were composed of crystalline hematite and maghemite. Scanning electron microscopy revealed that CP materials were more porous and homogeneous than NHSG materials. The results demonstrated the efficiency of the developed iron oxides in removing methylene blue via adsorption and heterogeneous Fenton degradation and clarified how synthesis method influences adsorptive and catalytic properties.

NiFe2O4 Nanoparticles: An Efficient Catalyst for One-Pot Three Component Synthesis of Acridinediones Derivatives

A nickel ferrite nanocatalyst was synthesized in the presence of simple and cost-effective polysorbates assisted sol gel method as an effective catalyst has been successfully used for one pot multicomponent Hantzsch condensation reaction of different aromatic aldehydes, dimedone and ammonium acetate under solvent-free condition at 110 °C-120 °C. The highlights feature for the synthesis of acridinediones are the recyclability of catalyst, solvent-free reaction condition, use of inexpensive catalyst, highly efficient, facile product isolation, clean reaction, nontoxic substances and great yields in short reaction time. The recovered catalyst can run four times without loss its activity.

Organic-Inorganic Hybrid Materials from Vegetable Oils.

The production of materials based on fossil resources is yielding more sustainable and ecologically beneficial methods. Vegetable oils (VO) are one example of base materials whose derivatives rival the properties of their petro-based counterparts. Gaps exist however and one way to fill them is by employing sol-gel processes to synthesize organic-inorganic hybrid materials, often derived from silane/siloxane compounds. Creating Si─O─Si inorganic networks in the organic VO matrix permits the attainment of necessary strength, among other property enhancements. Consequently, many efforts have been directed to optimally achieve organic-inorganic hybrid materials with VOs. However, compatibilization is challenging, and desirable conditions for matching the inorganic filler in the organic matrix remain a key stumbling block toward wider application. Therefore, this review aims to detail recent progress on these new hybrids, focusing on the main strategies to polymerize and functionalize the raw VO, followed by routes highlighting the addition of the inorganic fillers to obtain desirable composites.

Enhanced n-butanol sensing performance of Co3O4/LaFeO3 nanocomposites

Co3O4 and LaFeO3 composites were successfully prepared by sol–gel method and hydrothermal method. The morphology test results showed that Co3O4 nanoparticles uniformly attached to the surface of LaFeO3 nano-bricks. Gas sensing tests results showed that sensors based on Co3O4/LaFeO3 have lower operating temperatures and higher response than those of pure Co3O4 and LaFeO3, and better performance in response/recovery time and selectivity. The sample of Co3O4 and LaFeO3 with molar ratio of 1:1 is the best among all samples, with the response of 54.21 for 100 ppm n-butanol and 6.54 for 1 ppm n-butanol at 150 °C. The heterojunction and porous structure of Co3O4/LaFeO3 composite materials are the main reasons for improving its gas sensing performance.

Effect of Tungsten Doping on the Properties of Titanium Dioxide Dye-Sensitized Solar Cells

Tungsten-doped TiO2 thin films were prepared by sol–gel method on fluorine-doped tin oxide-coated substrates as working electrodes of dye-sensitized solar cells. The influences of different W doping (0, 2, 4, 6, and 8 at%) on the microstructure, optical, and photovoltaic properties of the W-TiO2 thin-film DSSCs were studied by the measurement of X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and electrochemical impedance spectroscopy (EIS). An optimal DSSCs performance was observed with a 6 at% W-doped TiO2 thin film, resulting in a Voc of 0.68 V, a Jsc of 20.2 mA/cm2, an FF of 68.6%, and an efficiency (η) of 9.42%. The efficiency of DSSCs with 6 at% W-doped TiO2 photoanode improved by 75%. This is because the 6 at% W-doped TiO2 thin film increases the specific surface area and electron transfer rate.

Activation mechanism of persulfate by Fe3C-based materials for efficient benzo-a-pyrene abatement in wastewater: The reversed direct electron transfer from persulfate to contaminants

Herein, an unusual reserved direct electron transfer (r-DET) process from persulfate (PS) to contaminants was observed on the surface of Fe3C with N-doped C shell supported on carbon nanotubes (Fe3C@CN-CNTs). The Fe3C-based materials were synthesized via a facile sol–gel method employing melamine, glucose, FeCl3, and commercial multi-walled CNTs. The activation mechanisms were fully explored with a comparison of Fe3C@CN-CNTs and other Fe3C-based materials for the effective abatement of benzo-a-pyrene (BaP), a typical persistent organic pollutant in industrial wastewater. Electrochemical measurements, zeta potential monitoring, and Mössbauer spectroscopy indicated that the lack of CN shell result the relatively large particle size of Fe3C on Fe3C-CNTs, leading to more negatively charged surface and abundant OH during PS activation. Nevertheless, the superparamagnetic fraction with a fine particle size on the surface of Fe3C@CN and Fe3C@CN-CNTs potentially leads to a more positively charged surface, enhancing the zeta potential of surface adsorbed BaP and benefiting the r-DET. Through r-DET, oxidized PS and reduced BaP formed as intermediates, accelerating the overall degradation of BaP in Fe3C@CN-CNTs/PS. The degradation pathways, cytotoxicity, and operation conditions of BaP degradation by Fe3C@CN-CNTs/PS were thoroughly investigated. Additionally, Fe3C@CN-CNTs were found to promote the nucleophilic reaction between Cl− and PS, producing free chlorine and enhancing BaP degradation efficiency in chloride-containing wastewater. Overall, this study presents a new insight for the PS-based r-DET process and offers a promising approach for treating organically-contaminated wastewater.

Study on UV-VIS characteristics of Aluminum Zinc Oxide nanoparticles through manganese substitution using Wemple-Di domenico method and diffuse reflectance spectroscopy

In this research Manganese-substitution impact on linear and nonlinear (NL) optical properties of Aluminum-doped ZnO (AlZnO) Nanoparticles (NPs) are investigated. Utilizing measured data of reflectance acquired from the DRS, the higher-order NL optical characteristics of the provided NPs are examined. The maximum quantity of NL susceptibility χ3 is measured to be around 3.945 × 10−10 esu at wavelength λ = 520 nm and 7.467 × 10−11 esu at wavelength λ = 530 nm for AlZnO and Manganese-substituted Aluminum-doped Zinc-Oxide (Mn-also) NPs, for particle sizes 14−67 nm and 11−54 nm, consecutively. Consequently, the synthesis method (sol–gel) which is used in this work concluded a decrease in particle size and different optical behavior especially in UV spectral regions during the substitution with Manganese in comparison with the AlZnO. This decrement assures that a decrease in the size of crystallite induces a decline in the χ3. The obtained optical parameters are red shifted with the Manganese substitution. Also, the NL absorption coefficient (β c(m/W)) is enhanced in the UV range. The maximum of the NL absorption coefficient (β c(m/W)), for AlZnO and Mn-AlZnO NPs, are determined (at λ = 250 nm) 2.24 × 10−18 (m/W) and 5.76 × 10−15 (m/W) respectively.