Enhanced photoanode properties of CdS nanoparticle sensitized TiO₂ nanotube arrays by solvothermal synthesis

Kalanur, S.S.,Lee, S.H.,Hwang, Y.J.,Joo, O.S. Elsevier Sequoia 2013 Journal of photochemistry and photobiology Chemist Vol.259 No.-

We demonstrate the synthesis of CdS-sensitized TiO<SUB>2</SUB> (CdS/TiO<SUB>2</SUB>) nanotube arrays via the solvothermal method and describe their enhanced photoelectrochemical properties. Our new approach prevents the clogging of CdS quantum dots (QDs) at the TiO<SUB>2</SUB> nanotube mouth and promotes the uniform deposition of a polycrystalline CdS on the densely aligned TiO<SUB>2</SUB> nanotube arrays (TiO<SUB>2</SUB> NTAs). The deposition of CdS onto the TiO<SUB>2</SUB> NTA can be controlled by the deposition time and the concentration of the precursors. Photoelectrochemical measurements indicate that the electrode synthesized via the solvothermal method can achieve a stable photocurrent density of 5.7mA/cm<SUP>2</SUP> at 0-V versus Ag/AgCl under AM 1.5G illumination, which is approximately 10% higher than that prepared using the chemical bath deposition (CBD) method. Solvothermally prepared CdS/TiO<SUB>2</SUB> NTAs exhibit 125-fold enhancement in their photocurrent under visible light compared with bare TiO<SUB>2</SUB> NTAs, indicating facile photogenerated electron transfer from CdS to TiO<SUB>2</SUB>. Solvothermally prepared CdS/TiO<SUB>2</SUB> NTAs shows better photostability and longer lifetime of photoelectrons compared to those prepared by CBD method suggesting more favorable CdS-TiO<SUB>2</SUB> NTA interfacial contact. In general, we propose that this methodology can be useful in designing multijunction semiconductor configuration such as coating nanostructures.

Synthesis and characterization of TiO₂ nanocrystals using a two-phase solvothermal method

홍성수,( Trinh Duy Nguyen ),이근대 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Highly crystalline and monodisperse TiO₂ nanoparticles have been prepared by using a two-phase solvothermal method. In this router, through the use both oleic acid and oleylamine as two distinct capping surfactants having different binding strengths the growth of the TiO₂ nanoparticles was controlled. Besides, the size, shape, and dispersibility of the as-prepared can be dominated by adjusting the concentration of reactants, reaction temperature and duration. Moreover, the photcatalytic activities of these oxides were evaluated by the decomposition of Rh B under UV irradiation.

Solvothermal 법에 의해 제조된 Sn-TiO2 나노 반도체 촉매 상에서의 수중 부유 톨루엔 광분해 반응

강미숙,김지연,김지은 한국청정기술학회 2010 청정기술 Vol.16 No.1

This study focuses on the removal of water-suspended toluene of a representative sick house compounds in a liquid photo-system using nanometer-sized Sn-incorporated TiO2 which was synthesized by a solvothermal method. The characteristics of the synthesized Sn-TiO2 were analyzed by X-ray Diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and UV-visible spectroscopy (UV-Vis). To estimate the photocatalytic activity of Sn-TiO2, the photodegradation of water-suspended toluene was performed, and the remaining concentration was determined using UV-visible spectroscopy. The water-suspended toluene photodegradation over Sn-incorporated TiO2 catalyst was better than that over pure TiO2 (anatase). The water-suspended toluene of 500 ppm was perfectly decomposed within 300 minutes over 0.01 mol% Sn-TiO2.

Synthesis of Al, Bi, and Fe-Ti Binary Metal Oxide Nanometer-sized Particles Using a Solvothermal Method and their Super-hydrophilicites

강미숙 한국공업화학회 2007 Journal of Industrial and Engineering Chemistry Vol.13 No.1

To study super-hydrophilic properties, nanometer-sized TiO2 particles containing Al, Bi, and Fe ions in +3 oxidation states (Metal3+) were prepared using a solvothermal method. These nanometer-sized TiO2 particles were characterized using XRD, FESEM, XPS, H2-TPR, and H2O-TPD analyses. As a result, Al, Bi, and Fe/TiO2 were obtained with pure anatase structures (20.30 nm in size, above 350 m2 g-1). The activation energy for dehydration decreased in the order Al-TiO2 > TiO2 > Fe-TiO2 > Bi-TiO2. The second XPS peak for O1s (TiOH), which related to the super-hydrophilicity, was the largest in Al-TiO2. In addition, the transference from Ti3+ to Tio, which related to the photo-activity, was easier over Al-TiO2 than it was for the other materials. The PL intensity decreased in the order Al-TiO2 > TiO2> Bi-TiO2 > Fe-TiO2, with the signals for the metal-TiO2 systems being shifted to longer wavelengths compared to that of pure TiO2. These results support our proposition that super-hydrophilicity was best in Al-TiO2 it resulted from a contact angle below 1o for water droplets under 365-nm radiation.

Facile synthesis of monodispersed 3D hierarchical Fe₃O₄ nanostructures decorated r-GO as the negative electrodes for Li-ion batteries

Kumar, S. Rajesh,Kim, Jong Guk,Viswanathan, C.,Kim, Won Bae,Selvan, R. Kalai,Ponpandian, N. Elsevier 2018 Materials research bulletin Vol.97 No.-

<P><B>Abstract</B></P> <P>One-pot solvothermal process is adopted to develop, 3D hierarchical Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles supported 2D reduced graphene oxide sheets (Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO) as possible negative electrodes for lithium ion batteries. The synthesis parameters are optimized to prepare agglomeration-free Fe<SUB>3</SUB>O<SUB>4</SUB> nanostructures with uniform size and shape on r-GO. The field emission scanning electron microscopic (FESEM) image reveals that the 3D hierarchical Fe<SUB>3</SUB>O<SUB>4</SUB> nanostructures are uniformly decorated on r-GO. The physicochemical and functional properties of Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO are systematically investigated using various techniques. The fabricated Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO electrode delivers an initial discharge capacity of 1221mAhg<SUP>−1</SUP> at a current density of 100mAg<SUP>−1</SUP> and retains the specific capacity of 1560mAhg<SUP>−1</SUP> after 100 cycles. Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO significantly enhances cyclic performance, when compared with bare Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles due to the uniform distribution of Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles on the graphene sheet with the more number of electrochemically active sites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Monodispersed Fe<SUB>3</SUB>O<SUB>4</SUB> nanostructures with different shapes synthesized by solvothermal method. </LI> <LI> The fabricated Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO electrode delivers an initial discharge capacity of 1221mAhg<SUP>−1</SUP> at 100mAhg<SUP>−1</SUP>. </LI> <LI> Fe<SUB>3</SUB>O<SUB>4</SUB>/r-GO significantly enhances the cyclic stability and rate capability than bare Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Solvothermal 법에 의해 제조된 Sn-TiO₂ 나노 반도체 촉매 상에서의 수중 부유 톨루엔 광분해 반응

김지연(Jiyeon Kim),김지은(Jieun Kim),강미숙(Misook Kang) 한국청정기술학회 2010 청정기술 Vol.16 No.1

본 연구에서는 새집증후군의 대표적 원인물질인 수중 부유 톨루엔을 효율적으로 분해하기 위해 Sn원소를 티타니아 골격에 삽입하여 고온 고압에서 용매열(solvothermal)법으로 Sn-TiO₂ 나노 광촉매를 제조하였다. 제조한 Sn-TiO₂의 물리적 특성은 X-ray 회절분석법, 투과전자현미경, 주사전자현미경, 자외선-가시선 분광 광도계를 통하여 분석하였다. Sn-TiO₂의 광촉매 활성은 수중 부유 톨루엔 광분해반응을 통해 확인하였고, 반응 전후의 수중 부유 톨루엔 농도는 자외선-가시선 분광광도계를 이용하여 측정하였다. 수중 부유 톨루엔 광분해반응 결과 0.01 mol% Sn-TiO₂ 촉매가 순수 TiO₂ (anatase) 광촉매보다 활성이 향상되었으며. 500ppm 수중 부유 톨루엔은 300분 이내에 완전히 분해되었다. This study focuses on the removal of water-suspended toluene of a representative sick house compounds in a liquid photo-system using nanometer-sized Sn-incorporated TiO₂ which was synthesized by a solvothermal method. The characteristics of the synthesized Sn-TiO₂ were analyzed by X-ray Diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and UV-visible spectroscopy (UV-Vis). To estimate the photocatalytic activity of Sn-TiO₂, the photodegradation of water-suspended toluene was performed, and the remaining concentration was determined using UV-visible spectroscopy. The water-suspended toluene photodegradation over Sn-incorporated TiO₂ catalyst was better than that over pure TiO₂ (anatase). The water-suspended toluene of 500 ppm was perfectly decomposed within 300 minutes over 0.01 mol% Sn-TiO₂.

Methyl orange removal over Zn-incorporated TiO₂ photo-catalyst

Kim, Y.,Lee, J.,Jeong, H.,Lee, Y.,Um, M.H.,Jeong, K.M.,Yeo, M.K.,Kang, M. Korean Society of Industrial and Engineering Chemi 2008 Journal of industrial and engineering chemistry Vol.14 No.3

This study focuses on the removal of the methyl orange (sodium p-dimethyl amino azo benzene sulfonate) of a representative dye compound in a liquid photo-system using nanometer-sized Zn-incorporated TiO<SUB>2</SUB> synthesized by a solvothermal method. The Zn-incorporated TiO<SUB>2</SUB> particles exhibited a mixed structure of anatase of TiO<SUB>2</SUB> and ZnTiO<SUB>3</SUB> with a particle size of below 20nm. The absorbance was shifted to the higher wavelength on 2.0mol% Zn-incorporated TiO<SUB>2</SUB> compared to pure TiO<SUB>2</SUB>. In the XRD pattern, the structure of ZnTiO<SUB>3</SUB> was seen at 2θ=31.75. The XPS result of O 1s confirmed that 2.0mol% Zn-TiO<SUB>2</SUB> had a higher hydrophilic property (Me-OH/Me-O=0.46) than pure TiO<SUB>2</SUB> (Me-OH/Me-O=0.25) did. Based on these results, the photodecomposition for methyl orange in liquid reaction was enhanced over Zn-incorporated TiO<SUB>2</SUB> compared with pure TiO<SUB>2</SUB>: methyl orange of 10ppm was completely decomposed after 120min over 2.0mol% Zn-incorporated TiO<SUB>2</SUB>.

Facile Synthesis of CdTe Nanorods from the Growth of Te Nanorods

Weiwei Xu,Jinzhong Niu,Guimin Tian,Xinghui Wu,Yongguang Cheng,Xiaoyang Hu,Haoshan Hao 대한화학회 2017 대한화학회지 Vol.61 No.4

One-dimensional CdTe nanorods (NRs) are obtained by the reaction of various Cd precursors with single crystalline Te nanorod templates, which are pre-synthesized from Te precursors by a simple and reproducible solvothermal method. Throughout the process, the diffraction intensity of different crystal facets of single crystalline Te NRs varied with reaction times. Finally, by alloying Cd ions along the axial direction of Te NRs, polycrystalline cubic phase CdTe NRs with diameters of 80–150 nm and length up to 1.2–2.4 μm are obtained. The nucleation and growth processes of Te and CdTe NRs are discussed in details, and their properties are characterized by XRD, SEM, TEM, Raman scattering, and UV-vis absorption spectra. It was found that the key elements of synthesizing CdTe NRs such as reaction temperatures and Cd sources will strongly influence the final shape of CdTe NRs.

Facile Synthesis of CdTe Nanorods from the Growth of Te Nanorods

Xu, Weiwei,Niu, Jinzhong,Zheng, Shuang,Tian, Guimin,Wu, Xinghui,Cheng, Yongguang,Hu, Xiaoyang,Liu, Shuaishuai,Hao, Haoshan Korean Chemical Society 2017 대한화학회지 Vol.61 No.4

One-dimensional CdTe nanorods (NRs) are obtained by the reaction of various Cd precursors with single crystalline Te nanorod templates, which are pre-synthesized from Te precursors by a simple and reproducible solvothermal method. Throughout the process, the diffraction intensity of different crystal facets of single crystalline Te NRs varied with reaction times. Finally, by alloying Cd ions along the axial direction of Te NRs, polycrystalline cubic phase CdTe NRs with diameters of 80-150 nm and length up to $1.2-2.4{\mu}m$ are obtained. The nucleation and growth processes of Te and CdTe NRs are discussed in details, and their properties are characterized by XRD, SEM, TEM, Raman scattering, and UV-vis absorption spectra. It was found that the key elements of synthesizing CdTe NRs such as reaction temperatures and Cd sources will strongly influence the final shape of CdTe NRs.

Controlled synthesis of hierarchical flower-like Sb2WO6 microspheres: Photocatalytic and superhydrophobic property

Chengyu Yang,Xiaojuan Yang,Feng Li,Taohai Li,Wei Cao 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.39 No.-

Functional Sb2WO6 samples were prepared by a solvothermal method. XRD and XPS spectroscopy wereused to demonstrate structures of the as-prepared Sb2WO6 samples. And the morphologies werecharacterized via SEM and TEM. Different morphologies of the Sb2WO6 samples can be convenientlyachieved by simply changing the pH value. The Sb2WO6microspheres were obtained when the pH = 2. Apossible formation process of Sb2WO6 microspheres was proposed. The Sb2WO6 microspheres have highphotocatalytic activity and stability for the degradation of Rhodamine B. Moreover, the wettability ofSb2WO6 microspheres was also investigated. Results suggest that Sb2WO6 surface has highsuperhydrophobicity.