Synthesis and characterisation of Ag incorporated TiO2 nanomaterials for supercapacitor applications

Enhanced photocatalytic and electrochemical properties of green synthesized strontium doped titanium dioxide nanoparticles for dye removal and supercapacitor applications

The development of multifunctional nanomaterials for environmental remediation and energy storage is critical for sustainable technologies. In this study, we synthesized strontium-doped titanium dioxide (Sr-TiO2) nanoparticles (NPs) via a green method and investigated their structural, optical, and electrochemical properties to enhance photocatalytic and supercapacitive performance. Characterization results confirmed successful Sr incorporation into the TiO2 lattice. X-ray diffraction (XRD) analysis revealed a slight shift in peak positions, indicating lattice distortion due to Sr doping. Scanning electron microscopy (SEM) showed uniform, well-dispersed nanoparticles, while energy-dispersive X-ray (EDX) spectra confirmed elemental composition. UV-visible spectroscopy (UV-Vis) demonstrated a redshift in absorption, reducing the bandgap and enhancing visible-light absorption. Fourier transform infrared (FTIR) spectroscopy identified characteristic functional groups, and Brunauer-Emmett-Teller (BET) analysis indicated increased surface area, favoring photocatalytic and electrochemical activity. The photocatalytic performance of Sr-TiO2 NPs was assessed through Methylene Orange (MO) and Congo Red (Con-R) degradation under visible light at different pH levels. Under optimized conditions, Sr-TiO2 NPs achieved 94.48% MO removal in 100 min and 97.89% Con-R removal in 70 min, following pseudo-first-order kinetics, demonstrating their efficiency as visible-light-driven photocatalysts for wastewater treatment. Electrochemical studies, including cyclic voltammetry (CV), charge-discharge tests, and electrochemical impedance spectroscopy (EIS), revealed improved charge storage and lower charge transfer resistance compared to bare TiO2. The Sr-TiO2 NPs exhibited enhanced specific capacitance and good electrochemical stability, underscoring their potential as high-performance electrode materials for supercapacitors. These findings highlight a sustainable approach to environmental remediation and energy storage by leveraging Sr-doped TiO2 nanomaterials for dual-functional applications.

A Review of Different Synthesis Approaches to Nanoparticles: Bibliometric Profile

Nanomaterials are currently one of the most popular emerging materials used in different applications such as drug delivery, water treatment, cancer treatment, electronic, food preservations, and production of pesticide. This is due to their interesting features including size-dependent properties, lightweight, biocompatibility, amphiphilicity and biodegradability. They offer wide possibilities for modification and are used in multiple functions with enormous possibilities. Some of them are medically suitable which has opened new opportunities for medical improvement especially for human health. These characteristics also make nanomaterials one of the pioneers in green materials for various needs, especially in environmental engineering and energy sectors. In this review, several synthesis approaches for nanoparticles mainly physical, chemical, and biological have been discussed extensively. Furthermore, bibliometric analysis on the synthesis of nanoparticles was evaluated. About 117,162 publications were considered, of which 92% are journal publications. RSC Advances is the most published outlet on the synthesis of nanoparticles and China has the highest number of researchers engaged in the synthesis of nanoparticles. It was noted in the evaluation of synthesis approach that biological approach is the savest method but with a low yield, while the chemical approach offers a high yield with some level of hazardous effect. Also, the bibliometric analysis revealed that the field of nanotechnology is a trending and hot ground for research.

Nickel-Cobalt Layered Double Hydroxide Nanosheet-Decorated 3D Interconnected Porous Ni/SiC Skeleton for Supercapacitor

In this study, a three-dimensional (3D) interconnected porous Ni/SiC skeleton (3D Ni/SiC) was synthesized by binder-free hydrogen bubble template-assisted electrodeposition in an electrolyte containing Ni2+ ions and SiC nanopowders. This 3D Ni/SiC skeleton served as a substrate for directly synthesizing nickel-cobalt layered double hydroxide (LDH) nanosheets via electrodeposition, allowing the formation of a nickel-cobalt LDH nanosheet-decorated 3D Ni/SiC skeleton (NiCo@3D Ni/SiC). The multiscale hierarchical structure of NiCo@3D Ni/SiC was attributed to the synergistic interaction between the pseudocapacitor (3D Ni skeleton and Ni-Co LDH) and electrochemical double-layer capacitor (SiC nanopowders). It provided a large specific surface area to expose numerous active Ni and Co sites for Faradaic redox reactions, resulting in an enhanced pseudocapacitance. The as-fabricated NiCo@3D Ni/SiC structure demonstrated excellent rate capability with a high areal capacitance of 1565 mF cm-2 at a current density of 1 mA cm-2. Additionally, symmetrical supercapacitor devices based on this structure successfully powered commercial light-emitting diodes, indicating the potential of as-fabricated NiCo@3D Ni/SiC in practical energy storage applications.

A Survey on Analytical Methods for the Characterization of Green Synthesized Nanomaterials

Nowadays, nanotechnologies are well established and the uses of a great variety of nanomaterials show exponential growth. The development of green synthesis procedures experienced a great development thanks to the contribution of researchers of diverse origins. The versatility of green chemistry allows producing a wide range of organic and inorganic nanomaterials with numerous promising applications. In all cases, it is of paramount importance to carefully characterize the resulting nanomaterials because their properties will determine their correct performance to accomplish the function to which they were synthesized or even their detrimental effects like nanotoxicological behavior. This review provides an overview of frequently employed characterization methods and their applications for green synthesized nanomaterials. However, while several different nanoscale materials and their associated green construction methodology are being developed, other important techniques would be extensively incorporated into this field soon. The aim is to encourage researchers in the field to employ a variety of these techniques for achieving an exhaustive characterization of new nanomaterials and for contributing to the development of validated green synthesis procedures.

Effect of Particle Size on the Mechanical Properties of TiO2-Epoxy Nanocomposites

This study investigated the effects of the packing density and particle size distribution of TiO₂ nanoparticles on the mechanical properties of TiO₂–epoxy nanocomposites (NCs). The uniform dispersion and good interfacial bonding of TiO₂ in the epoxy resin resulted in improved mechanical properties with the addition of nanoparticles. Reinforcement nano-TiO₂ particles dispersed in deionized water produced by three different ultrasonic dispersion methods were used; the ultrasonication effects were then compared. The nano-TiO₂ suspension was added at 0.5–5.0 wt.%, and the mechanical and thermal properties of TiO₂–epoxy NCs were compared using a universal testing machine, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). The tensile strength of the NCs was improved by the dispersion strengthening effect of the TiO₂ nanoparticles, and focused sonication improved the tensile strength the most when nano-TiO₂ suspensions with a particle size of 100 nm or smaller were used. Thus, the reinforcing effect of TiO₂ nanoparticles on the epoxy resin was observed, and the nano-TiO₂ suspension produced by focused sonication showed a more distinct reinforcing effect.

Green Synthesis and Applications of ZnO and TiO2 Nanostructures

Over the last two decades, oxide nanostructures have been continuously evaluated and used in many technological applications. The advancement of the controlled synthesis approach to design desired morphology is a fundamental key to the discipline of material science and nanotechnology. These nanostructures can be prepared via different physical and chemical methods; however, a green and ecofriendly synthesis approach is a promising way to produce these nanostructures with desired properties with less risk of hazardous chemicals. In this regard, ZnO and TiO2 nanostructures are prominent candidates for various applications. Moreover, they are more efficient, non-toxic, and cost-effective. This review mainly focuses on the recent state-of-the-art advancements in the green synthesis approach for ZnO and TiO2 nanostructures and their applications. The first section summarizes the green synthesis approach to synthesize ZnO and TiO2 nanostructures via different routes such as solvothermal, hydrothermal, co-precipitation, and sol-gel using biological systems that are based on the principles of green chemistry. The second section demonstrates the application of ZnO and TiO2 nanostructures. The review also discusses the problems and future perspectives of green synthesis methods and the related issues posed and overlooked by the scientific community on the green approach to nanostructure oxides.