Facile Chemical Precipitation Route Research Articles

Rapid synthesis of triple-layered cylindrical ZnO@SiO2@Ag core-shell nanostructures for photocatalytic applications

Core-shell nanocomposites are promising materials in the degradation of harmful chemicals released from industries/factories. In this work, ZnO@SiO2@Ag triple–layered core-shell nanocomposites synthesized by a facile chemical precipitation route at 400 °C using as-prepared ZnO@SiO2 samples as a precursor were investigated for photocatalytic application. The synthesized ZnO@SiO2 and ZnO@SiO2@Ag samples were characterized using XRD, SEM, TEM, XPS, and UV-Vis spectrometer. The XRD studies showed that both nanocomposites possess the hexagonal wurtzite crystalline phase of the core ZnO. Moreover, the average crystallite sizes of ZnO@SiO2@Ag composites determined from the XRD spectra were found to be 27.98 nm and 30.56 nm for reaction times of 4 h and 12 h, respectively. The SEM and TEM analyses indicate that the morphologies of the samples were rod-shaped. The UV-Vis spectroscopy showed that the ZnO@SiO2@Ag nanoparticles exhibited maximum absorbance peak at 363 nm with a calculated band gap energy of 3.13 eV. In addition, the photocatalytic activity and stability were analyzed by a photoreduction method using the photodegradation property of organic methylene blue under UV-Vis light irradiation. Compared with the “bare” ZnO@SiO2 samples, the stability and photocatalytic performance of the Ag coated ZnO@SiO2@Ag nanocomposites were highly enhanced, and the reasons for the enhancement are discussed.

Influence of annealing temperature on visible-light photocatalytic activities of Ag3PO4 particulates synthesized using CH3COOAg as a precursor

Ag3PO4 microparticles (MPs) were prepared through a facile chemical precipitation route and using silver acetate (AgAc) as metal salt. The effect of annealing temperature (Ta) and time (τa) on the actual photocatalytic (PC) activity of Ag3PO4 MPs is investigated. The optimal annealing parameters are Ta of 400 °C and τa of 90 min. The enhanced PC activity by annealing at 400 °C is ascribed to the increase of electron mobility. Besides, an Ag3PO4 photoelectrode was fabricated through a drop-coating deposition route, which demonstrates a photocurrent density of 80 μA/cm2 and acceptable stability. The n-type conduction behavior of Ag3PO4 is verified by a Mott-Schottky (M-S) plot.

Strontium and ciprofloxacin modified hydroxyapatites as functional grafts for bone prostheses

Both strontium and ciprofloxacin are known to be functional materials for the treatment of bone diseases associated to the loss of bone substance. In this work we prepared the strontium (Sr) modified hydroxyapatite (SrHA) and ciprofloxacin (Cip) modified SrHA bone substitutes by one pot facile chemical precipitation route. The calcium release is improved more for SrHA compared with stoichiometric HA owing to the higher solubility of the Sr. Drug release profile exhibited the sustained and prolonged release of Cip up to 45 days. The in-vitro cell responses showed that the Sr addition improved the ALP activity of the osteoblast like MG-63 cells which confirms the enhanced cell viability and functionality of the strontium modified hydroxyapatite ceramics.

Facile One Pot Synthesis of CuO Nanostructures and Their Effect on Nonenzymatic Glucose Biosensing

Morphology of different CuO nanostructures is controlled by changing the precursor counterions. The CuO nanostructures were synthesized using three different precursor salts of copper namely acetate, nitrate, and sulfate via facile chemical precipitation route. The synthesized CuO nanostructures were thoroughly characterized using X-ray diffraction, optical spectroscopy, electron microscopy etc. The nanostructures were studied for catalytic nonenzymatic glucose sensing applications. CuO nanostructures synthesized from copper sulfate having flower-like morphology showed the highest glucose sensitivity of 1830 μAmM−1cm−2 in a linear range of 0.01–0.2 mM with a detection limit of 8 μM.

Structure, morphology and photocatalytic activity of attapulgite/Ag3PO4 hybrids synthesized by a facile chemical precipitation route

Attapulgite (ATP)/Ag3PO4 hybrids have been synthesized via a facile chemical precipitation route, and we also examined the effect of precursor phosphate types on the structure, morphology and photocatalytic property of the obtained products. It was found that the ATP surfaces were uniformly coated by ultrathin Ag3PO4 nanoparticles (NPs) with sizes of 5–20 nm, while the as-synthesized hybrids exhibited the higher photocatalytic activities for methyl orange degradation than the single Ag3PO4 crystals although the amount of active species were decreased a lot. The behavior was thus attributed to both the smaller particle sizes and the larger surface. In addition, it was also observed that the photocatalytic activities of those hybrids were dependent on the types of phosphate salts. In details, a few impurities were found in the samples synthesized via Na3PO4, while the ones synthesized using two other phosphates (Na2HPO4, NaH2PO4) exhibited the higher photocatalytic activities and stabilities due to the higher loading amount, smaller size and more uniform coating of Ag3PO4 NPs. This work presents a new approach for expanding the possibilities for developing low cost and visible-light responsive photocatalysts.

LaPO4-coated Li1.2Mn0.56Ni0.16Co0.08O2 as a cathode material with enhanced coulombic efficiency and rate capability for lithium ion batteries

Layered Li[Li0.2Mn0.56Ni0.16Co0.08]O2 porous microspheres have been successfully synthesized by a urea combustion method, and then coated with appropriate amount of LaPO4via a facile chemical precipitation route.

Probing the dominance of interstitial oxygen defects in ZnO nanoparticles through structural and optical characterizations

ZnO nanoparticles, synthesized adopting a facile chemical precipitation route, are studied here. The structural, optical and electronic properties of prepared ZnO nanoparticles were extensively investigated employing X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive analysis by X-rays (EDAX), X-ray photoelectron spectroscopy (XPS), UV–vis absorption and fluorescence (FL) spectroscopy. The XRD analysis revealed hexagonal wurtzite phase 26.1–29.6nm size ZnO nanocrystallites. This observation gets further support from TEM images where particles of 25–30nm size are vividly seen. Interestingly, oxygen rich stoichiometry of nanoparticles is detected via zinc and oxygen emission lines of EDAX spectrum. XPS analysis establishes coexistence of lattice oxygen (OL), interstitial oxygen (Oi) and oxygen vacancy (VO) in ZnO nanoparticles. In line with EDAX analysis, XPS investigations substantiate interstitial oxygen rich composition of nanoparticles. Blue shift of absorption energy, as observed in the UV–vis spectrum of ZnO nanoparticles, typically manifests quantum confinement effect. Such transitions indicate the occurrence of various discrete energy states of prepared nanoparticles. FL spectroscopic investigations ascertain the existence of these discrete states by probing the radiative transitions arising among such states. Finally, FL study not only demonstrates visible emissions emanating from the oxygen defect states but more remarkably, in concurrence with EDAX and XPS analysis, establishes the excess of interstitial oxygen defects in prepared ZnO nanoparticles.

Controllable synthesis and growth mechanism of α-Co(OH) 2 nanorods and nanoplates by a facile solution-phase route

A facile chemical precipitation route has been developed to control synthesis of α-cobalt hydroxide nanostructures with rod-like and plate-like morphologies. The α-Co(OH) 2 nanorods were achieved in large quantity when the experiments were carried out in the presence of a suitable shape-controlling reagent polyvinyl pyrrolidone (PVP), while the α-Co(OH) 2 nanoplates were obtained when the experiments were conducted in the absence of PVP, whilst keeping other experimental conditions constant. The chemical composition and morphologies of the as-prepared α-Co(OH) 2 nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The effect of polymer PVP on the morphologies of α-Co(OH) 2 nanoparticles were discussed in detail. The results indicated that PVP played a key role for the formation of α-Co(OH) 2 nanorods. The growth mechanism of the as-synthesized nanorods and nanoplates were discussed in detail based on the experimental results. A possible growth mechanism has been proposed to illustrate the growth of α-Co(OH) 2 nanorods.