Solution combustion synthesis (SCS) has been widely used to produce simple and complex oxides with a desired morphology (size and shape). SCS is valuable due to low cost, simplicity and energy efficient synthesis. To guarantee the best molecular-level mixing of reactants in an aqueous or solvent-based solution some parameters need to be controlled, such as fuel type, metal cations precursors, stoichiometry ratio (φ), pH effect, atmosphere and initiation type. These determine the final properties of the oxide materials, providing the potential to reach different morphologies, which are essential for their final applications. This Review article focuses on the crucial parameters in SCS and how these affect the overall materials properties from nanostructures to thin films. To finalize, special attention is given to the application of SCS to form metal oxide thin films at low temperature and their application in thin film transistors (TFTs).

Solution Combustion Synthesis: Towards a Sustainable Approach for Metal Oxides.

Electronic structure and photocatalytic activity of samarium doped cerium oxide nanoparticles for hazardous rose bengal dye degradation

A review on electrical and gas-sensing properties of reduced graphene oxide-metal oxide nanocomposites

Nanomaterials for high frequency device and photocatalytic applications: Mg-Zn-Ni ferrites

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.

https://www.mdpi.com/1420-3049/26/8/2236/pdf

Green Synthesis and Applications of ZnO and TiO2 Nanostructures.

Materials reduced to the Nano scale can exhibit different properties compared to what they exhibit on a micro scale, enabling unique applications. When TiO2 is reduced to Nano scale it shows unique properties, of which the electrical aspect is highly important. This paper presents increase in the energy gap and decrease in conductivity with decrease in particle size of pure Nano TiO2 synthesized by hydrolysis and peptization of titanium isopropoxide. Aqueous solution with various pH and peptizing the resultant suspension will form Nano TiO2 at different particle sizes. As the pH of the solution is made acidic reduction in the particle size is observed. And it is confirmed from XRD using Scherer formula and SEM, as prepared samples are studied for UV absorbance, and DC conductivity from room temperature to 400°C. From the tauc plot it was observed, and calculated the energy band gap increases as the particle size decreases and shown TiO2 is direct band gap. From Arrhenius plot clearly we encountered, decrease in the conductivity for the decrease in particle size due to hopping of charge carriers and it is evident that, we can tailor the band gap by varying particle size.

Effect of particle size on band gap and DC electrical conductivity of TiO2 nanomaterial

Chromium doped ceria nanoparticles have been synthesized by using a novel solution combustion method with chromium nitrate hexahydrate as oxidizers and glycine as a fuel The main objective of the present study is to find the effect of chromium on structural, optical, dielectric properties and ac- conductivity of cerium oxide nanoparticles (CeO2 NPs) The prepared samples were characterized by various physicochemical techniques such as UV–Vis absorption spectra, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDS) analysis The powder XRD patterns confirm the cubic fluorite structure of CeO2 NPs The UV–Vis absorption spectra showed that the doping causes the red shift of absorption peaks The optical band gap of all samples has been measured by Tauc plot, which is found to be decreases with chromium concentration The uniform shaped NPs with the range of ~ 20 nm is observed by FESEM images EDS analysis confirms the expected elemental composition of Ce1−xCrxO2 NPs The dielectric constant ɛ′, dielectric loss factor (tanδ) and AC conductivity of the samples were studied as function of frequency range from 20 Hz to 3 MHz and found to be decreases with increasing the chromium content

V. S. Chaturmukha

Papers

Effect of particle size on band gap and DC electrical conductivity of TiO2 nanomaterial

Synthesis and dielectric properties of Cr-substituted CeO 2 nanoparticles

Influence of zinc on the structural and electrical properties of cerium oxide nanoparticles

Temperature Dependent Dielectric Constant and AC Conductivity of Porous CeO2 Nanoparticles Obtained by Solution Combustion Method

Synthesis and dc electrical conductivity of Cr-doped CeO 2 nanoparticles by solution combustion method