What are the properties of ZnSO4.7H2O?4 answersZnSO4.7H2O is a hydrated salt that has been studied for its potential as a heat storage material for space heating applications. It offers high energy storage density, low cost, and a clean means of long-term solar energy storage. The dehydration and hydration processes of ZnSO4.7H2O were investigated, and it was found that 85% of water is lost at 100°C during dehydration, releasing 699 J/g of energy. The hydration process at 100°C recovers 541 J/g of enthalpy. The thermal behavior of ZnSO4.7H2O was also studied, and it was observed that at higher temperatures, agglomeration occurs, affecting the hydration rate. Additionally, ZnSO4.7H2O has been synthesized as mixed structure nanoparticles, with the presence of c-ZnS, h-ZnS, and h-ZnO phases. The nanoparticles exhibit wide optical transparency in the ultraviolet region, with optical band gap values ranging from 4.16 eV to 4.40 eV. The solubility of ZnSO4.7H2O in water increases linearly with temperature, and the crystals have good thermal stability. The efficacy of methionine-modulated bioavailability of dietary ZnSO4.7H2O has been studied in common carp, showing improved zinc uptake in different tissues. Thermodynamic parameters for the ZnSO4-H2O system have been derived using the CALPHAD method, successfully predicting the solubility of zinc sulfate under various conditions.
How can ZnMoO4 be grown uniformly?5 answersZnMoO4 can be grown uniformly by utilizing different methods. One approach is to synthesize a rationally designed 1D composite nanofiber architecture through a two-step process involving electrospinning and thermal oxidation. Another method is the polymer network gel method, which triggers radical polymerization and cross-linking reactions to form a three-dimensional network, resulting in uniform particle size and small particle size. Chemical deposition can also be used to directly form a uniform ridge-like ZnMoO4 layer on the Zn anode, inducing uniform zinc nucleation and inhibiting dendrite growth. Laser ablation in liquid combined with hydrothermal method can also be employed to prepare ZnMoO4 nanowires with high absorption in the ultraviolet region. These various techniques offer ways to achieve uniform growth of ZnMoO4 for different applications.
Why ZnMoO4 bandgap widen with dopant?3 answersThe bandgap of ZnMoO4 widens with dopant due to the introduction of impurity atoms. In the case of ZnO, the bandgap increases when doped with p-type impurities such as Na and Cl. Similarly, Nd-doping in ZnO leads to a slight widening of the bandgap, with the conduction band shifting towards lower energy regions. Ti doping in ZrO2 also causes a red-shift in the optical absorption edge, resulting in a larger bandgap. Additionally, Mg doping in ZnO thin films leads to a significant increment in the bandgap. Finally, the bandgap of ZnO doped with III group elements (Ga, In, Tl, Y, Sc, La) is broadened due to the increase in doping concentrations.
What are the basic properties, structure and appearance of ZnMoO4?5 answersZnMoO4 is a compound with a triclinic crystal structure and a cubic-like morphology. It can be synthesized using different methods such as solid-state reaction, polymer network gel method, and precipitation-freeze drying method. The compound exhibits various properties depending on its synthesis method and dopants. The bandgap of ZnMoO4 can be tuned by introducing dopants such as Cu and Ni, resulting in a decrease in bandgap and potential application in the visible region of the electromagnetic spectrum. ZnMoO4 also shows good dispersibility and improved electrochemical performance, making it a promising anode material for lithium-ion secondary batteries. Additionally, ZnMoO4 nanostructures doped with Ni exhibit reverse saturable absorption and negative nonlinearities, suggesting their potential use in optical device applications. The compound also has a high-quality factor and can be used as high signal speed microwave material. Overall, ZnMoO4 has a triclinic crystal structure, cubic-like morphology, and various properties that can be tailored for different applications.
How to increase the band gap of ZnO?5 answersTo increase the band gap of ZnO, several approaches have been explored. One method is to introduce dopants into the ZnO structure. Doping with transition metals such as Cr, Fe, Mn, and Nb has been found to decrease the band gap and shift it towards the visible region. Another approach is to reduce the dimensionality of the ZnO film. Studies have shown that reducing the thickness and orientation of the film can enhance the band gap, resulting in a wider range of optoelectronic applications. Additionally, the properties of ZnO films can be influenced by the oxidation temperature and the nature of the film support material. Overall, these methods offer potential strategies for increasing the band gap of ZnO and tailoring its optoelectronic properties.
How can ZnO nanoparticles be synthesized?4 answersZnO nanoparticles can be synthesized using various methods. One method is the green synthesis approach, where Tabernaemontana divaricata flower extract is used as a reducing agent. Another method is the sol-gel chemical precipitation technique, where zinc acetate and sodium hydroxide are used as starting materials. Hydrothermal synthesis is another method, where ammonia and zinc chloride are used. Additionally, a low-temperature, supercritical-fluid-driven synthesis has been proposed, which results in nanosized particles with a pure excitonic emission. A simple and cost-effective chemical co-precipitation method can also be used for synthesis. These methods offer different advantages in terms of ease of synthesis, control over particle size, and purity of the resulting nanoparticles.