Green Hydrothermal Synthesis Research Articles

One-pot green hydrothermal synthesis of stearate-intercalated MgAl layered double hydroxides

A convenient one-pot green hydrothermal synthesis method has been developed to obtain stearate-intercalated layered double hydroxide (LDH-St), an important nanofiller for polymer/LDH nanocomposites. Various factors of the hydrothermal synthesis conditions, including reaction time, temperature and solid content, were taken into account. The resulting products were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma (ICP) atomic emission spectrophotometry, CHN elemental analysis, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The increase of reaction time or solid content is helpful to the formation of LDH-St, whereas high reaction temperature had little effect. Deduced from PXRD and the composition analysis results, prolonging of reaction time led to a packing arrangement transformation from a bilayer-like structure with stearate acids co-intercalated to monolayer for the intercalated stearate anions in the interlayer space. In addition the prepared LDH-St crystallites showed flower-like aggregates with a diameter of about 8–10μm consisting of sheets with irregular shape.

Hydrothermal synthesis of hydroxyapatite nanorods and nanowires using riboflavin-5′-phosphate monosodium salt as a new phosphorus source and their application in protein adsorption

Hydroxyapatite (HA), as the main inorganic constituent in vertebrate hard tissues, is an important biomaterial for the application in drug delivery and protein adsorption. Herein, we report a simple and green hydrothermal synthesis of HA nanorods and nanowires by using the biocompatible biomolecule riboflavin-5′-phosphate monosodium salt (RP) as a new phosphorus source. In this method, the RP molecules hydrolyze to form inorganic phosphate ions under hydrothermal conditions, and these phosphate ions react with calcium ions to form HA nanorods or nanowires after nucleation and crystal growth. The effects of experimental conditions including hydrothermal temperature, heating time and pH value of the initial solution on the hydrolysis process of RP molecules are investigated. A possible formation mechanism of HA nanorods and nanowires is proposed. The as-prepared HA nanorods and nanowires are explored for the potential application in protein adsorption. The hemoglobin (Hb) loading capacities of HA nanowires and HA nanorods increase with increasing initial Hb concentration. The Hb loading capacities of HA nanowires and HA nanorods are determined to be as high as 289 mg g−1 and 298 mg g−1, respectively, at an initial Hb concentration of 2000 mg mL−1. The pH-dependent Hb release property of Hb-loaded HA nanowires and HA nanorods has been found. The experimental results indicate that the products are promising for applications in protein adsorption.

Green hydrothermal synthesis of ZnO nanotubes for photocatalytic degradation of methylparaben

A green hydrothermal method was proposed for the synthesis of ZnO nanotubes (NTs) using ZnO powder and 30vol% H2O2 aqueous solution as the starting materials. The as-prepared ZnO NTs with diameter around 10nm and wall thickness of 3–5 nm were formed by scrolling of layer nanosheet. A possible formation mechanism was proposed. By utilizing the as-prepared ZnO NTs as photocatalysts, significant photocatalytic degradation was observed towards endocrine disrupting chemical (EDC) methylparaben under UV irradiation. The superior photocatalytic degradation of methylparaben was owing to the unique tubular structure and large surface area of prepared ZnO NTs, which might enhance the electron and hole separation and might lead to the formation of a large amount of reactive radicals.

One-pot green hydrothermal synthesis of CuO–Cu2O–Cu nanorod-decorated reduced graphene oxide composites and their application in photocurrent generation

Download options Please wait... Supplementary files Supplementary information PDF (442K) Article information DOI https://doi.org/10.1039/C2CY20406A Article type Communication Submitted 14 Jun 2012 Accepted 23 Jul 2012 First published 09 Aug 2012 Download Citation Catal. Sci. Technol., 2012,2, 2227-2230 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions One-pot green hydrothermal synthesis of CuO–Cu2O–Cu nanorod-decorated reduced graphene oxide composites and their application in photocurrent generation J. Tian, H. Li, Z. Xing, L. Wang, Y. Luo, A. M. Asiri, A. O. Al-Youbi and X. Sun, Catal. Sci. Technol., 2012, 2, 2227 DOI: 10.1039/C2CY20406A To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Jingqi Tian Haiyan Li Zhicai Xing Lei Wang Yonglan Luo Abdullah M. Asiri Abdulrahman O. Al-Youbi Xuping Sun

Two-Step Green Hydrothermal Synthesis of ZnO Powders

ZnO2 nanoparticles were synthesized via hydrothermal reaction between Zn5(CO3)2(OH)6 powder and 30 mass% H2O2 aqueous solution at 80 °C for 24 h, and ZnO powders with granular and rodlike morphologies were synthesized via hydrothermal decomposition of the as-synthesized ZnO2 nanoparticles in water at 150-170 °C for 24 h. The obtained products were characterized by X-ray diffraction, Raman and Field emission scanning electron microscopy.

Green hydrothermal synthesis and optical absorption properties of ZnO 2 nanocrystals and ZnO nanorods

A green hydrothermal method was proposed for the controllable synthesis of ZnO 2 nanocrystals and ZnO nanorods, using the common and cost-effective 2ZnCO 3·3Zn(OH) 2 powder and 30 mass% H 2O 2 aqueous solution as the raw materials. The characterization results from X-ray diffraction, high resolution transmission electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the products synthesized at 100–120 °C for 6 h or at 170 °C for 0 h were cubic phase ZnO 2 nanocrystals; while those synthesized at 170 °C for 3–6 h were hexagonal phase ZnO nanorods. The UV–vis absorption spectra showed that the as-synthesized ZnO 2 nanocrystals and ZnO nanorods had optical band gaps of about 4.1 and 3.3 eV, respectively.

Green hydrothermal synthesis and characterization of CdO 2 nanoparticles

A green hydrothermal method has been developed for the synthesis of CdO 2 nanoparticles from Cd(OH) 2 powder and 6 vol.% H 2O 2 aqueous solution at 80–150 °C. The characterization results from X-ray diffraction, transmission electron microscopy, and thermal gravimetric and differential scanning calorimetry analysis disclosed that the resultant products were pure cubic phase CdO 2 nanoparticles with the sizes in the range of about 11–13 nm. The UV–vis absorption spectra revealed that the as-synthesized CdO 2 nanoparticles had similar optical band gaps of about 3.85 eV. The Raman spectra of the as-synthesized CdO 2 nanoparticles displayed two obvious peaks at about 348 and 830/833 cm –1, a characteristic of pyrite-type IIB-peroxides.

Green hydrothermal synthesis and photoluminescence property of ZnO 2 nanoparticles

ZnO 2 nanoparticles were synthesized via a green hydrothermal method using ZnO powder and 30% H 2O 2 aqueous solution as the starting materials, and characterized by X-ray diffraction (XRD), Raman spectra, energy dispersive X-ray (EDX) spectra, field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and room temperature photoluminescence (RTPL) spectra. It was found that suitable reaction temperature (e.g., 80–140 °C) played an important role in obtaining pure cubic phase ZnO 2 nanoparticles. The RTPL spectra disclosed that the as-synthesized ZnO 2 nanoparticles exhibit one strong emission band centered at around 400 nm and one very weak emission band at around 474 nm, which may have originated from the band edge emission and the oxygen vacancy, respectively.

Green hydrothermal synthesis and optical properties of cuprous bromide nanocrystals

Zincblende structure cuprous bromide (γ-CuBr) nanocrystals were synthesized via a green hydrothermal method, which was based on the reactions of CuSO 4·5H 2O, KBr and d-glucose in distilled water in an autoclave at 100 °C for 12–24 h. The structure, composition and optical properties of the resultant products were characterized by means of X-ray powder diffraction (XRD), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), UV–vis absorption and room temperature photoluminescence (RTPL) spectra. A possible reduction–precipitation mechanism was also proposed for the formation of CuBr in the present system.