Weerachon Phoohinkong

Active Ilmenite Surface Structure Influence of Acid Assisted Ball Milling

Active-ilmenite powder derived from natural ilmenite sand was prepared by the ball milling process with acid-solution and Deionized (DI) water. Morphology and particle size of active-ilmenite product in acid/DI-assisted ball milling process were monitored by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Surface atomic component and chemical bonding were investigated by X-ray photoelectron spectroscopy (XPS). Meanwhile, bulk chemical oxidation and fine structure of active-ilmenite were studied by X-ray absorption near edge structure (XANES) and extended X-ray absorption ne-structure spectroscopy (EXAFS) to confirm the oxidation state and local active species structure at surface. Active-ilmenite by acid-assisted ball milling process is a distinctive method for the preparation of active-ilmenite product with high active surface. Moreover, the distortion of TiO6 and FeO6 octahedral cluster on the sample surface was detected in all milled samples with acid-assisted ball milling process. The presence of Fe2+, Fe3+ ions and miniature sulfate was also detected on the sample surface by milled product with acid-assisted method.

Extraction and characterization of nanocellulose from sugarcane bagasse by ball-milling-assisted acid hydrolysis

This study is proposed to characterize nanocellulose extracted from sugarcane bagasse (SCB). For extracting cellulose, the bagasse was treated by chemical treatment. The nanocellulose was prepared using ball-milling with acid hydrolysis. Morphology of bagasse, cellulose and nanocellulose were characterized by scanning electron microscopy (SEM). The chemical composition of extracted cellulose and nanocellulose was investigated by Fourier-transformed infrared spectroscopy that verifying the removal of lignin and hemicellulose during cellulose isolation process from sugarcane bagasse. The crystalline structure of cellulose and nanocellulose were characterized by X-ray diffraction (XRD), indicating that the nanocellulose prepared by ball milling with acid hydrolysis has higher crystallinity than nanocellulose prepared only ball milling.This study is proposed to characterize nanocellulose extracted from sugarcane bagasse (SCB). For extracting cellulose, the bagasse was treated by chemical treatment. The nanocellulose was prepared using ball-milling with acid hydrolysis. Morphology of bagasse, cellulose and nanocellulose were characterized by scanning electron microscopy (SEM). The chemical composition of extracted cellulose and nanocellulose was investigated by Fourier-transformed infrared spectroscopy that verifying the removal of lignin and hemicellulose during cellulose isolation process from sugarcane bagasse. The crystalline structure of cellulose and nanocellulose were characterized by X-ray diffraction (XRD), indicating that the nanocellulose prepared by ball milling with acid hydrolysis has higher crystallinity than nanocellulose prepared only ball milling.

Comparison Study of Photocatalytic Activity of Titanium-Rich Materials Derived from Natural Minerals Ores Using Acidic Leaching

Over past decades, titanium dioxide-based materials have been recognized as effectively practical photocatalysts for purification of toxicity waste. However, pure TiO2 photocatalyst is highly active under ultraviolet illumination. In this work, the effort has been focused on the synthesis of titanium-rich materials starting from minerals ores ilmenite ores and leucoxene ores by ball-milling process in combined with hydrochloric acid leaching method with optimized conditions. Crystallinity and morphologies of as-prepared samples were characterized by X-rays diffraction technique and scanning electron microscope. The photocatalytic activities of both derived-materials were studied and compared by degradation of Rhodamine B organic dye as organic toxicity compound under ultraviolet light and visible light. The results illustrate that the leucoxene-derived sample exhibits superior catalytic performance to the sample derived from ilmenite ores due to the greater Ti-content of the starting leucoxene ores.

Preparation of Nanosized Manganese Oxide Particles via Solid-State Route Reaction

nanosized manganese oxide particles are attracted considerable interest in many industry areas especially in energy storage device applications because of their unique properties. For industry large scale synthesis, it needs a simple and low energy technique for scaling up production process. In this work, nanosized manganese oxide particles were prepared via a solid-state reaction route at room temperature. The products were characterized by field emission scanning electron microscopy (FE-SEM) coupled with energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction infrared spectroscopy (XRD), and raman spectroscopy. The results show that the sizes of particles were smaller than 50 nm with narrow size distribution and high yield were obtained. In addition, this technique may be applicable to industry production of nanosized manganese oxide or nanosized manganese oxide composite.

Effect of Cobalt Dopant on Structural and Optical Properties of Co-Precipitated TiO2 Nanopowders

The effects of cobalt (Co) addition on structural and optical properties of TiO2 nanopowders have been investigated. A co-precipitation method was employed to synthesize TiO2 nanoparticles with various Co additives from 0-10 mol% using tetrabutyl titanate and Cobalt (II) nitrate hexahydrate as starting precursors for Ti and Co source, respectively. The crystallinity of Co-doped TiO2 nanopowders is heightened by calcination process. The crystal structure, phase formation and the corresponding functional groups of Co-doped TiO2 were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The scanning electron microscope (SEM) was taken to observe their morphologies. The chemical compositions of Co additive into TiO2 matrix are confirmed by EDAX. Their optical properties were investigated by diffuse reflectance spectroscopy. Diffuse reflectance spectra of samples exhibit the increasing absorption in visible region with an increasing Co content. The overall characterization results indicated that the crystallinity and optical properties of TiO2 nanoparticles are significantly affected by Co dopant.

Photocatalytic Performance of Ball-Milled Anatase/Rutile Mixed Phase TiO2 Composite Powders

Mixed-phase anatase/rutile titanium dioxide (TiO2) composite powder is an important material due to the unique properties of photocatalytic activity that is higher than that of the only single anatase or rutile phase. In this study, the anatase/rutile mixed phase TiO2 composite powders were prepared by ball milling of TiO2 commercial grade powders. Effect of the anatase/rutile phase ratio and milling time on photocatalytic performance were investigated. The sample phase ratio is evaluated using X-ray diffraction (XRD) meanwhile the composite morphology is characterized using field emission scanning electron microscope (FE-SEM). The overall results revealed that the mixed-phase anatase/rutile provided significant enhancement in photocatalytic performance comparing to only anatase or rutile single phase. In addition, this ball-milling technique is considered as an effective process and cost-effectively on energy saving suitable for preparing anatase/rutile mixed-phase TiO2 for photocatalytic application.