Papers by Keyword: Hydrothermal Method

Abstract: In this study, nanocrystalline ZnO-TiO2 hybrid metal oxide was successfully synthesized using a low-temperature hydrothermal method at 90 °C for 24 hours. Zinc nitrate hexahydrate, titanium (IV) oxide, and sodium hydroxide were employed as reactants without any additives. The synthesized ZnO-TiO2 hybrid nanomaterial was characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanningelectron microscopy (FE-SEM), and Energy dispersive X-ray spectroscopy (EDAX). XRD results confirmed the presence of hexagonal zincite (ZnO) and rutile (TiO2) phases, with crystallite sizes of 60.28 nm and 48.12 nm, respectively. FT-IR analysis identified metal-oxide stretching vibrations, while FESEM revealed a granular and rod-like morphology, consistent with XRD results. EDAX confirmed the elemental purity of the hybrid metaloxide, detecting only Zn, Ti, and O elements. Due to its high crystallinity and controlled morphology, the ZnO-TiO2 hybrid nanomaterial has potential applications in gas sensing, environmental remediation, and energy-related fields.

Abstract: To address the limitations of traditional drug delivery, CaTiO₃:Er³⁺ film (CTO:Er) is studied as a promising material for drug delivery systems. With regard to the excellent biocompatibility and physicochemical properties, CTO:Er prepared by a facile electrochemical anodizing process combined with a hydrothermal method has been used to fabricate new drug-releasing implants for localized drug delivery. This review discusses the development of CTO:Er applied in localized drug delivery systems, which uses nano drug curcumin for testing. Furthermore, with the special structure of the material, it meets the needs of drug absorption and delivery. Finally, the review concludes with the advances of CTO:Er for controlled drug delivery and corresponding prospects in the future.

Abstract: Graphene oxide (GO) was prepared by two methods; Modified Hummer’s as well as Improved Hummer’s methods. Similarly reduced graphene oxide (rGO) was also prepared by two methods namely chemical and hydrothermal methods. Chemically rGO was prepared using urea and aluminium powder while hydrothermally rGO was prepared using autoclave and hot air oven. The sample obtained were characterized using UV-Visible, FTIR, XRD and Raman spectroscopy. The result of the given samples obtained by the above methods for GO and rGO were compared and analyzed which showed that the hydrothermal route is better due to its simplicity and non-toxicity than chemical route but used for small scale production. These findings highlight the advantages of the hydrothermal method for GO and rGO synthesis, providing valuable insights for future research and development in graphene-based materials.

Abstract: In the present research work, carbon nanosphere (5 wt. %, 10 wt. % and 15 wt. %)/Zr- based metal organic frame works (CNS: Zr (II)-MOFs) with different molar ratios of the legend 4-{[(1E)-1-Hydroxy-3-Oxoprop-1-En-2-yl] Sulfanyl} Benzoic Acid (HOSBA) have been successfully synthesized by hydrothermal method. Studies using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA) have validated certain structural, optical, and morphological features. The supercapacitance performance of the synthesized MOFs was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). At a current density of 0.5 A g^-1 and at a scan rate of 10 mV/s, the 15% CNS doped Zr-MOF demonstrated highest specific capacitance (C_s) of 239.4 F g^-1. 15 wt.% CNS doped Zr-MOF proven power density of 2100 W kg^-1 and maximum energy density of 14.82 Wh Kg^-1 with capacitive retention of 77.63 % following 2000 cycles mark this combination a good for supercapacitors (SCs) material. Regardless of the synthetic conditions, we achieved MOFs which exhibited hetero structure formation with spherical morphologies. The results open us new and energy approach for the supercapacitor of the Zr-metal based MOFs and applications in the photonics, optoelectronics, and promising electrode material for electrochemical energy storage systems.

Abstract: In order to improve the wear resistance of aluminum matrix composites and reduce the cost at the same time, the Al₂O₃/Al composite powder was prepared by hydrothermal method in this experiment, and the material properties of the Al₂O₃/Al metal matrix composite powder material were studied. It can be seen from the results that the encapsulation degree of Al₂O₃/Al-based composite powder material first increases and then decreases with the increase of ammonia concentration, and first increases and then decreases with the increase of PH value. The optimal molar ratio of salt and alkali is 1:1. Through the optimization of process parameters, the ratio of aluminum nitrate and ammonia water is obtained as: 1:1, the slurry stirring speed is 1500r/min, the stirring time is 10min, and the heating temperature is 200°C, the obtained composite powder is relatively uniform, has a larger specific surface area, and has better powder properties.

Abstract: The main issues that limit the large-scale application of TiO₂ in photocatalysis is its low utilization of solar energy and high recombination rate of photogenerated charges. To overcome these limitations, a type II WO₃·H₂O/TiO₂ heterojunction has been prepared via a one-step mild hydrothermal method that uses Na₂WO₄·2H₂O and P25 as the starting materials and proceeds at 150°C without requiring any post-heat treatment for crystallization, special solvents or additives. The XRD and HRTEM results show that the prepared powders were composed of orthorhombic WO₃·H₂O and TiO₂, and demonstrate the existence of the WO₃·H₂O/TiO₂ heterojunctions. The photocatalytic activity of the as-prepared WO₃·H₂O/TiO₂ heterojunction powders was investigated by using the degradation of phenol. The WO₃·H₂O/TiO₂ heterojunction powders exhibited the best photocatalytic performance when the nominal W/Ti ratio was 6.57%, and showed better photocatalytic performance than commercial P25 and orthorhombic WO₃·H₂O.

Abstract: A two-stage hydrothermal method was used to prepare rapid-switching electrochromic WO₃/ZnO composite electrodes. The morphology of the nanorods was altered by changing the precursor concentration. A higher precursor concentration inhibited the growth of crystals and declined the crystallinity of nanorods. Nanorods with a diameter of 48 nm, height of 92.5 nm, and transmittance greater than 80% were grown when the precursor concentration in the second step was 1.5 times that in the first step. The electrochromic electrode demonstrated rapid coloring and bleaching speeds (5 and 0.8 s, respectively), which were faster than those of the electrode prepared using the one-stage process.

Abstract: Fundamental and applied research depends on the removal of organic toxic effluents from textile industries. Photocatalytic dye degradation of CuO-NiO nanocomposite has been studied against methylene blue (MB) dye. CuO-NiO nanocomposite has been prepared by hydrothermal method using radish (Raphanus sativus) leaves as green fuel. Prepared composite nanoparticles (NPs) are characterized by XRD, FTIR, UV-DRS and SEM with EDS for the elemental and structural information. XRD data indicated the formation of monoclinic and hexagonal crystallite structures for CuO and NiO respectively. FTIR confirmed the presence of Cu - O and Ni - O molecular vibrations. Surface morphology and elemental composition of composite was analysed by SEM with EDS. CuO-NiO nanocomposite is capable to degrade 70 % of methylene blue (MB) dye in 180 min under UV light interactions. Recyclability is also good even after 4 cycles of degradation experiment for the CuO-NiO composite.

Abstract: Photocatalytic reduction of 4-nitrophenol is one of the most promising methods to remove this hazardous pollutant from wastewaters and generated a raw compound widely use in industrial processes. In the present work, three Bi₂S₃/TiO₂ catalysts with different Bi₂S₃ content, were synthesized by a hydrothermal method. The materials were characterized by XRD, X-ray fluorescence, physisorption of N₂, HRTEM, UV-Vis reflectance spectroscopy and zeta potential measurements. The catalytic activity of the synthesized materials was tested in the photoreduction of 4-nitrophenol in aqueous medium. Although the results indicate the formation of heterojunction for all the samples, the physicochemical properties of each material depend on the Bi₂S₃ content. The material with 6%wt of Bi₂S₃ exhibit the major catalytic activity, reducing 80% of the target molecule within 60 minutes of reaction.

Abstract: Zinc oxide-titanium dioxide (ZnO-TiO₂) have been successfully synthesized by hydrothermal method. ZnO-TiO₂ nanocomposite were prepared at different molar ratio 100:0, 100:0, 30:70, 50:50 and 70:30. The objective of this research is to determine the effect of molar ratios on the structural and optical properties of ZnO-TiO₂ nanocomposite. The samples were analyzed using X-ray diffraction (XRD) analysis, Field-emission scanning electron microscopy (FESEM) and UV-Vis spectroscopy. Based on the XRD results, it is revealed that ZnO-TiO₂ nanocomposite consists of hexagonal wurtzite structure of ZnO and mixed of anatase/ rutile phase of TiO₂. FESEM images showed ZnO in rod-like structure while TiO₂ is formed in nanoparticle. ZnO-TiO₂ composite is formed combination of rod-like and nanoparticles. UV-Vis spectra showed that all samples exhibited good absorption towards UV region. The calculated energy band gaps of ZnO-TiO₂ composite are 2.92 eV which is slightly smaller compared to bulk ZnO and TiO₂. The tuning energy band gaps of ZnO-TiO₂ composite samples is a good indicator for use in catalytic activities.