Photocatalytic conversion of sugars to 5-hydroxymethylfurfural using aluminium(III) and fulvic acid

5-hydroxymethylfurfural (HMF) is a valuable and essential platform chemical for establishing a sustainable, eco-friendly fine-chemical and pharmaceutical industry based on biomass. The cost-effective production of HMF from abundant C6 sugars requires mild reaction temperatures and efficient catalysts from naturally abundant materials. Herein, we report how fulvic acid forms complexes with Al³⁺ ions that exhibit solar absorption and photocatalytic activity for glucose conversion to HMF in one-pot reaction, in good yield (~60%) and at moderate temperatures (80 °C). When using representative components of fulvic acid, catechol and pyrogallol as ligands, 70 and 67% HMF yields are achieved, respectively, at 70 °C. Al³⁺ ions are not recognised as effective photocatalysts; however, complexing them with fulvic acid components as light antennas can create new functionality. This mechanism offers prospects for new green photocatalytic systems to synthesise a range of substances that have not previously been considered.

Plasmonic Silver-Nanoparticle-Catalysed Hydrogen Abstraction from the C(sp3 )-H Bond of the Benzylic Cα atom for Cleavage of Alkyl Aryl Ether Bonds

Selective activation of the C(sp³ )-H bond is an important process in organic synthesis, where efficiently activating a specific C(sp³ )-H bond without causing side reactions remains one of chemistry's great challenges. Here we report that illuminated plasmonic silver metal nanoparticles (NPs) can abstract hydrogen from the C(sp³ )-H bond of the C_α atom of an alkyl aryl ether β-O-4 linkage. The intense electromagnetic near-field generated at the illuminated plasmonic NPs promotes chemisorption of the β-O-4 compound and the transfer of photo-generated hot electrons from the NPs to the adsorbed molecules leads to hydrogen abstraction and direct cleavage of the unreactive ether C_β -O bond under moderate reaction conditions (≈90 °C). The plasmon-driven process has certain exceptional features: enabling hydrogen abstraction from a specific C(sp³ )-H bond, along with precise scission of the targeted C-O bond to form aromatic compounds containing unsaturated, substituted groups in excellent yields.

Surface‐Plasmon‐Enhanced Transmetalation between Copper and Palladium Nanoparticle Catalyst

Surface‐plasmon‐mediated phenylacetylide intermediate transfer from the Cu to the Pd surface affords a novel mechanism for transmetalation, enabling wavelength‐tunable cross‐coupling and homo‐coupling reaction pathway control. C−C bond forming Sonogashira coupling and Glaser coupling reactions in O₂ atmosphere are efficiently driven by visible light over heterogeneous Cu and Pd nanoparticles as a mixed catalyst without base or other additives. The reaction pathway can be controlled by switching the excitation wavelength. Shorter wavelengths (400–500 nm) give the Glaser homo‐coupling diyne, whereas longer wavelength irradiation (500–940 nm) significantly increases the degree of cross‐coupling Sonogashira coupling products. The ratio of the activated intermediates of alkyne to the iodobenzene is wavelength dependent and this regulates transmetalation. This wavelength‐tunable reaction pathway is a novel way to optimize the product selectivity in important organic syntheses.

Nanostructure Shape-Effects in ZnO heterogeneous photocatalysis

Selective oxidation of alcohols is an essential reaction for fine chemical production. Here, the photocatalytic oxidation of benzyl alcohol by zinc oxide (ZnO) nanocrystals was investigated to clarify the mechanism of selective oxidation with this process. Reactivity when in contact with three distinct ZnO nanocrystal shapes: nanocones, nanorods and nanoplates, was studied in order to compare crystal facet-specific effects in the reaction system. The same non-hydrothermal and non-hydrolytic aminolysis method was used to synthesise all three nanocrystal shapes. The ZnO catalysts were characterized using by a range of techniques to establish the key properties of the prominent ZnO crystal facets exposed to the reaction medium. The ZnO nanocrystals photocatalysed the benzyl alcohol oxidation reaction when irradiated by a 370 - 375 nm LED output and each ZnO crystal morphology exhibited different reaction kinetics for the oxidation reaction. ZnO nanocones displayed the highest benzyl alcohol conversion rate while nanorods gave the lowest. This established a facet-dependent kinetic activity for the benzyl alcohol reaction of (101¯1) > (0001) > (101¯0). Experimental and density functional theory computation results confirm that the {101¯1} facet is a surface that exposes undercoordinated O atoms to the reaction medium, which explains why the reactant benzyl alcohol adsorption on this facet is the highest. Light irradiation can excite valence band electrons to the conduction band, which are then captured by O₂ molecules to yield superoxide (O₂^•-). In a non-aqueous solvent, the photogenerated holes oxidise benzyl alcohol to form a radical species, which reacts with O₂^•- to yield benzaldehyde. This results in 100% product selectivity for benzaldehyde, rather than the carboxylic acid derivative.

AN IN VIVO STUDY OF INTRAVITREAL RANIBIZUMAB FOLLOWING SUBRETINAL INOCULATION OF RB CELLS IN RABBITS EYES

AIM

This study aimed to determine the effects of a single intravitreal ranibizumab injection in rabbits induced with retinoblastoma (RB).

MATERIAL AND METHODS

RB was induced in six New Zealand white rabbits by subretinal injection of a cultured WERI-RBb-1 cell line into the right eye. After six weeks, Group A (n = 3) was given intravitreal ranibizumab injection (0.3mg in 0.03ml) and Group B (n = 3) was the control. Baseline and serial clinical examinations were performed on days 1, 3, 6, 12, 15, 18 and 21. The right eyes were enucleated for both groups on day 21 for histopathological examination.

RESULTS

The rabbits in both groups developed intraocular lesions which was detectable clinically at one-week post-tumor inoculation. The tumor grew slowly without spontaneous regression. After the animals in Group A were given an intravitreal ranibizumab injection, regression of the tumor was detected clinically, while the tumor in Group B continued to grow slowly. Histopathological findings confirmed the presence of a tumor that closely resembled features of poorly differentiated human RB cells. At the end of 21 days, the size of the tumor was larger in Group B in comparison to Group A. However, the treated group also developed a focal area of retinal hyperplasia. There was no significant side effect of ranibizumab injection except temporary high intraocular pressure immediately post-injection, which was relieved after paracentesis.

CONCLUSIONS

Intravitreal ranibizumab is a potential treatment for RB. It is an effective therapy with a tolerable safety profile in this animal experimental study.

High efficient arsenic removal by In-layer sulphur of layered double hydroxide

High-risk arsenic contamination found in aqueous system is reported across the world and causing severe environmental issues. In this study, the Mg-Al Layered Double Hydroxide (LDH) modified by sulphur species (LDH-S) was found exhibiting high effectivity and selectivity in As(V) removal owing to the strong interaction between embedded HS^- and AsO₄^3-. The LDH-S with Mg to Al ratio 2-1 give the best performance with As(V) adsorption capacity 40.8 mg/g, which is 715% higher than that of pristine LDH (2-1). The adsorbent exhibits a high tolerance to concentrated competitive anions. In the continuous flow test, the adsorbent can reduce the As(V) concentration from 20 ppm to below-ppb-level indicating the potential in industry application. The adsorption mechanism is experimentally investigated and examined by Density Function Theory (DFT) calculation. The result illustrates that, differ from the traditional ion exchange mechanism of LDH, the enhanced removal capacity and selectivity of LDH-S for As(V) is attributed to the strong affinity between H atom from HS- ion (in the interlayer region of LDH) and the O atom from AsO₄^3-.

A rare presentation of ectopic thyroid gland at right axilla

The thyroid gland and its hormones play important roles in organ development and in the homeostatic control of physiological mechanisms in human beings. As a result of embryogenic descent of thyroid gland, it commonly resides along the midline - from tongue to mediastinum (90%). Ectopic thyroid gland is a rare occurrence, with extra-lingual ectopic thyroid gland being even rarer. Thus, there is a concern for malignant metastasis. Madam H, a 56-year-old healthy woman presented to the Hospital Sultanah Nora Ismail, Johor, Malaysia in April 2020 with an increasing size of right axilla mass and history of weight loss. She was having right axilla mass for the previous 7 years but only noticed the increase in size about 1 year ago. She has no other constitutional symptoms. A tru-cut biopsy performed demonstrated a benign ectopic thyroid tissue. Thyroid function test showed primary hypothyroidism. Serum Chromogranin A and other thyroid antibodies were within the normal value. Further radiological imaging showed the normal thyroid gland at neck, with no signs of distant malignancy. There was no other axillary, mediastinal or hilar lymph node enlargement. She was started on regular T. L Thyroxine 100mcg daily and given regular follow-up in endocrine clinic. Benign ectopic thyroid gland is an unusual finding. As such, follow up is needed with possibility of carcinomatous transformation such as papillary carcinoma should be considered.

Catalysis based on ferroelectrics: controllable chemical reaction with boosted efficiency

Catalysts, which can accelerate chemical reactions, show promising potential to alleviate environmental pollution and the energy crisis. However, their wide application is severely limited by their low efficiency and poor selectivity due to the recombination of photogenerated electron-hole pairs, the back-reaction of interactants. Accordingly, ferroelectrics have emerged as promising catalysts to address these issues with the advantages of promoted light adsorption, boosted catalytic efficiency as a result of their intrinsic polarization, suppressed electron-hole pair recombination, and superior selectivity via the ferroelectric switch. This review summarizes the recent research progress of catalytic studies based on ferroelectric materials and highlights the controllability of catalytic activity by the ferroelectric switch. More importantly, we also comprehensively highlight the underlying working mechanism of ferroelectric-controlled catalysis to facilitate a deep understanding of this novel chemical reaction and guide future experiments. Finally, the perspectives of catalysis based on ferroelectrics and possible research opportunities are discussed. This review is expected to inspire wide research interests and push ferroelectric catalysis to practical applications.

Oxidative Esterification of 5-Hydroxymethylfurfural into Dimethyl 2,5-Furandicarboxylate Using Gamma Alumina-Supported Gold Nanoparticles

Gold nanoparticles (Au NPs) supported on a nanostructured gamma alumina (γ-Al₂O₃) fiber can exhibit excellent catalytic activity for the conversion of 5-hydroxymethylfurfural to produce its ester derivative, dimethyl 2,5-furandicarboxylate (FDMC). γ-Al₂O₃ was synthesized using a PEG surfactant to generate oxide fibers that randomly stack together into irregular shapes. The average particle sizes of the Au NPs are 1-6 nm, where the catalytically active Au (111) surface is the exposed facet. This 3D nanocatalyst architecture enhances the 5-hydroxymethylfurfural (HMF) oxidative esterification because HMF reactant molecules can readily diffuse into this fibrous structure and adsorb to active catalytic sites, while ester product molecules can diffuse out. Up to 99% HMF conversion and 90% FDMC selectivity can be obtained at a low reaction temperature of 45 °C, and the catalyst shows excellent recyclability. Increasing the Au content in the catalyst minimizes the requirement of a base for HMF conversion. Thus, the Au NPs supported on γ-Al₂O₃ can drive HMF esterification to FDMC efficiently with high product selectivity under very mild reaction conditions, omitting the need for an additional esterification step of the HMF acid.

Direct visible photoexcitation on palladium nanocatalysts by chemisorption with distinct size dependence

Direct photoexcitation of metal nanoparticles (NPs) can induce selective chemical reactions that are difficult to achieve with thermal energy.

Visible-light photocatalytic selective oxidation of C(sp3)–H bonds by anion–cation dual-metal-site nanoscale localized carbon nitride

Anion–cation dual-metal-site nanoscale localized carbon nitride exhibits a significantly enhanced photocatalytic activity for the oxidation of alkanes and alcohols with a high activity and a wide functional group tolerance.

Heterogeneous photocatalytic anaerobic oxidation of alcohols to ketones by Pt-mediated hole oxidation

We report a platinum nanocluster/graphitic carbon nitride (Pt/g-C₃N₄) composite solid catalyst with a photocatalytic anaerobic oxidation function for highly active and selective transformation of alcohols to ketones. The desirable products were successfully obtained in good to excellent yields from various functionalized alcohols at room temperature, including unactivated alcohols. Mechanistic studies indicated that the reaction could proceed through a Pt-mediated hole oxidation initiating an α-alcohol radical intermediate followed by a two-electron oxidation pathway. The merit of this strategy offers a general approach towards green and sustainable organic synthetic chemistry.

Strongly interfacial-coupled 2D-2D TiO2/g-C3N4 heterostructure for enhanced visible-light induced synthesis and conversion

Two-dimensional (2D) nanosheet-based nanocomposites have attracted intensive interest owing to the unique electronic and optical properties from their constituent phases and the synergistic effect from the heterojunctions. In this study, an interfacial coupled TiO₂/g-C₃N₄ 2D-2D heterostructure has been prepared via in situ growth of ultrathin 2D-TiO₂ on dispersed g-C₃N₄ nanosheets. This strongly coupled 2D-2D TiO₂/g-C₃N₄, different from the weakly bonded 2D-TiO₂/g-C₃N₄ heterostructures produced by mechanical mixing, has unique electronic structures and chemical states due to strong interlayer charge transfer, confirmed by both experimental and theoretical analyses. Significantly enhanced visible-light responses have been observed, indicating a great potential for visible-light induced photosynthesis and photocatalysis. For benzylamine coupling reactions under visible-light irradiation, 80 % yield rate has been achieved, superior to ∼30 % yield rate when adopting either 2D-TiO₂ or g-C₃N₄ structure. The enhanced photocatalytic activity can be attributed to the adequate separation of photo-generated electrons at the strongly coupled 2D-2D heterojunction interfaces.

Simultaneous removal of cationic and anionic heavy metal contaminants from electroplating effluent by hydrotalcite adsorbent with disulfide (S2-) intercalation

Hydrotalcite materials are generally utilized for anionic pollutants due to its interlayered anion exchange ability. Their potentiality for cationic contaminants is rarely explored. In this study, disulfide (S^2-) intercalated LDH material demonstrated capability to remove both heavy metal cations and oxyanions simultaneously from water. The S^2- intercalation of LDH significantly improved its adsorption capability towards both heavy metal cations (Co²⁺ and Ni²⁺) and oxyanion (CrO₄^2-). The adsorption amount of S-LDH towards Co²⁺ and Ni²⁺ reached 88.6mg/g and 76.2mg/g, which are 405% and 281% higher than that of pristine LDH. For CrO₄^2- removal, the adsorption amount reached 34.7mg/g, 402% higher than that of pristine LDH. The cations capture mechanism mainly depends on the novel layer sheet cation substitution mechanism based on irreversible precipitation and the generation of metal sulfide precipitates. Meanwhile, the interlayered S^2- can be easily replaced by CrO₄^2- to realize the simultaneous removal of both heavy metal cations and oxyanions. In the fixed-bed column experiments, 448 bed volume (BV) (672 mL) of simulating electroplating wastewater can be efficiently treated by yielding only 1 BV(15 mL) of chemical sludge, which is practically acceptable. This work provided a highly practical adsorption technology based on the S^2- modification hydrotalcite material for the purification of heavy metal ions contaminated wastewater.

Quantifying the influence of surface physico-chemical properties of biosorbents on heavy metal adsorption

Heavy metals present in industrial wastewater contribute to human and ecosystem health risk when discharged without proper treatment. Low-cost biosorbents with high metal-binding capacity are increasingly being utilized for the removal of heavy metals. Inherent physico-chemical properties of biosorbents significantly influence their adsorption capacity. Studies quantifying the influence exerted by these properties on adsorption capacity are scarce. This study quantifies the influence and relative importance of selected physico-chemical properties on the adsorption capacity of three divalent heavy metals; Cu²⁺, Cd²⁺ and Pb²⁺ using multivariate analysis. Twenty one biosorbent mixtures were created, systematically varying their physico-chemical properties using tea factory waste and coconut shell biochar. Their adsorption capacities were measured using batch sorption studies. The influence of physico-chemical properties on the adsorption capacity is comparable for all three metal cations. Regression models were developed to quantify the influence of physico-chemical parameters on the adsorption capacity based on regression coefficients. All models were found to have high reliability with R² values above 0.98. Acidic surface functional groups were found to act as the key property that governs the adsorption capacity of Pb²⁺, Cu²⁺ and Cd²⁺. Carboxylic groups played a major role in the adsorption of Cu²⁺ and Pb²⁺, while lactonic groups were more important in providing binding sites to Cd²⁺. SSA failed to demonstrate a significant impact on the adsorption capacity of these three metals on its own when the biosorbent had a low surface functional group density.

Gambaran Psychological Well-Being Pekerja Sosial Dian Bersinar Foundation Medan

<p>Dian Bersinar Foundation adalah yayasan yang memberikan pendidikan bagi anak-anak pinggiran rel kereta api, secara khusus di daerah Thamrin Plaza dan juga anak-anak yang bermukim di Kelurahan Aur, Medan. <em>Psychological well-being</em> berkaitan dengan bagaimana seseorang mampu berfungsi positif secara psikologis dalam hidupnya, yang diukur dengan melihat enam dimensi yaitu penerimaan diri, hubungan positif dengan orang lain, otonomi, penguasaan lingkungan, tujuan dalam hidup serta pertumbuhan pribadi. Dengan kondisi hidup dan bekerja yang dialami pekerja sosial, tujuan dilakukannya penelitian ini adalah untuk mendapatkan gambaran tentang kondisi <em>psychological well-being</em> pekerja sosial Dian Bersinar Foundation Medan serta faktor-faktor apa saja yang menyebabkan dan memengaruhi kondisi <em>psychological well-being</em>nya. Penelitian dilakukan dengan wawancara dan observasi terhadap satu orang subjek dan dua orang informan, yaitu rekan kerja dan anak didik subjek di Dian Bersinar Foundation. Hasil penelitian menunjukkan kondisi  <em>psychological well-being</em> pada subjek juga dipengaruhi oleh perasaan bahagia, faktor dukungan sosial dan religiusitas.</p>

Visible light-driven selective hydrogenation of unsaturated aromatics in an aqueous solution by direct photocatalysis of Au nanoparticles

Selective hydrogenation of various chemical bonds, such as CC, CC, CO, NO, and CN, is efficiently driven by visible light over a supported gold nanoparticle (AuNP) photocatalyst under mild reaction conditions.

Minat Berwirausaha Ditinjau dari Kepribadian Extraversion pada Mahasiswa Fakultas Ekonomi Universitas Dharmawangsa Medan

Penelitian ini bertujuan untuk mengetahui hubungan antara kepribadian <em>extraversion </em>dengan minat berwirausaha. Hipotesis yang diajukan dalam penelitian ini adalah adanya hubungan positif antara kepribadian <em>extraversion </em>dengan minat berwirausaha, dengan asumsi semakin <em>extraversion </em>kepribadian yang dimiliki individu, maka semakin tinggi minat berwirausaha, dan sebaliknya semakin lemah kepribadian <em>extraversion </em>yang dimiliki individu, maka semakin rendah minat berwirausaha. Subjek penelitian yang digunakan dalam penelitian ini adalah mahasiswa-mahasiswi Fakultas Ekonomi Universitas Dharmawangsa Medan sebanyak 125 orang yang dipilih dengan metode <em>purposive sampling</em>. Data diperoleh dari skala untuk mengukur kepribadian <em>extraversion </em>dan minat berwirausaha. Perhitungan dilakukan dengan melakukan uji prasyarat analisis (uji asumsi) yang terdiri dari uji normalitas dan uji linearitas. Analisis data yang digunakan adalah menggunakan korelasi <em>Product Moment </em>melalui bantuan SPSS 15 <em>for Windows</em>. Hasil analisis data menunjukkan koefisien korelasi sebesar 0,535 (p &lt; 0.05). Ini menunjukkan ada hubungan positif antara kepribadian <em>extraversion </em>dengan minat berwirausaha. Hasil penelitian ini menunjukkan bahwa sumbangan yang diberikan variabel kepribadian <em>extraversion </em>terhadap minat berwirausaha adalah sebesar 28,6 persen, selebihnya 72,4 persen dipengaruhi oleh faktor lain seperti <em>self efficacy, locus of control</em>, lingkungan keluarga, pengetahuan kewirausahaan, dan motivasi berprestasi. Dari hasil penelitian ini dapat ditarik kesimpulan bahwa hipotesis penelitian ada hubungan positif antara kepribadian <em>extraversion </em>dengan minat berwirausaha dapat diterima.

Photon Energy Threshold in Direct Photocatalysis with Metal Nanoparticles: Key Evidence from the Action Spectrum of the Reaction

By investigating the action spectra (the relationship between the irradiation wavelength and apparent quantum efficiency of reactions under constant irradiance) of a number of reactions catalyzed by nanoparticles including plasmonic metals, nonplasmonic metals, and their alloys at near-ambient temperatures, we found that a photon energy threshold exists in each photocatalytic reaction; only photons with sufficient energy (e.g., higher than the energy level of the lowest unoccupied molecular orbitals) can initiate the reactions. This energy alignment (and the photon energy threshold) is determined by various factors, including the wavelength and intensity of irradiation, molecule structure, reaction temperature, and so forth. Hence, distinct action spectra were observed in the same type of reaction catalyzed by the same catalyst due to a different substituent group, a slightly changed reaction temperature. These results indicate that photon-electron excitations, instead of the photothermal effect, play a dominant role in direct photocatalysis of metal nanoparticles for many reactions.

Silver and palladium alloy nanoparticle catalysts: reductive coupling of nitrobenzene through light irradiation

Silver and palladium alloy nanoparticle catalysts for reductive coupling of nitrobenzene through light irradiation.

Efficient Removal of Cationic and Anionic Radioactive Pollutants from Water Using Hydrotalcite-Based Getters

Hydrotalcite (HT)-based materials are usually applied to capture anionic pollutants in aqueous solutions. Generally considered anion exchangers, their ability to capture radioactive cations is rarely exploited. In the present work, we explored the ability of pristine and calcined HT getters to effectively capture radioactive cations (Sr(2+) and Ba(2+)) which can be securely stabilized at the getter surface. It is found that calcined HT outperforms its pristine counterpart in cation removal ability. Meanwhile, a novel anion removal mechanism targeting radioactive I(-) is demonstrated. This approach involves HT surface modification with silver species, namely, Ag2CO3 nanoparticles, which can attach firmly on HT surface by forming coherent interface. This HT-based anion getter can be further used to capture I(-) in aqueous solution. The observed I(-) uptake mechanism is distinctly different from the widely reported ion exchange mechanism of HT and much more efficient. As a result of the high local concentrations of precipitants on the getters, radioactive ions in water can be readily immobilized onto the getter surface by forming precipitates. The secured ionic pollutants can be subsequently removed from water by filtration or sedimentation for safe disposal. Overall, these stable, inexpensive getters are the materials of choice for removal of trace ionic pollutants from bulk radioactive liquids, especially during episodic environmental crisis.

Non-plasmonic metal nanoparticles as visible light photocatalysts for the selective oxidation of aliphatic alcohols with molecular oxygen at near ambient conditions

Non-plasmonic Pd NPs and Pt NPs exhibit superior visible light photocatalytic activity and distinctly different product selectivity in the oxidation of aliphatic alcohols.

Visible light-driven photocatalytic Heck reaction over carbon nanocoil supported Pd nanoparticles

This paper presents a carbon nanocoil supported Pd nanoparticle system (Pd/CNCs) as a photocatalyst for coupling reaction of aryl halides and alkenes (Heck reaction) at 40 °C.

Factors influencing the photocatalytic hydroamination of alkynes with anilines catalyzed by supported gold nanoparticles under visible light irradiation

The hydroamination of alkynes with amines is successfully driven by visible-light when using AuNPs on metal oxide supports as plasmonic photocatalysts.

Silver oxide nanocrystals anchored on titanate nanotubes and nanofibers: promising candidates for entrapment of radioactive iodine anions

Iodine radioisotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials. The (129)I(-) anion is one of the more mobile radioactive species due to a long half-life, and it is a great challenge to design long-term management solutions for such radioactive waste. In this study, a new adsorbent structure with the potential to efficiently remove radioactive iodine anions (I(-)) from water is devised: silver oxide (Ag2O) nanocrystals firmly anchored on the surface of titanate nanotubes and nanofibers via coherent interfaces between Ag2O and titanate phases. I(-) anions in fluids can easily access the Ag2O nanocrystals and be efficiently trapped by forming AgI precipitate that firmly attaches to the adsorbent. Due to their one-dimensional morphology, the new adsorbents can be readily dispersed in liquids and easily separated after purification; and the adsorption beds loaded with the adsorbents can permit high flux. This significantly enhances the adsorption efficiency and reduces the separation costs. The proposed structure reveals a new direction in developing efficient adsorbents for the removal of radioactive anions from wastewater.

Titanate-based adsorbents for radioactive ions entrapment from water

This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process.

Removal of radioactive iodine from water using Ag2O grafted titanate nanolamina as efficient adsorbent

Emergency treatment of radioactive material leakage and safety disposal of nuclear waste is a constant concern all along with the development of radioactive materials applications. To provide a solution, titanate with large surface area (143 m(2)g(-1)) and a lamina morphology (the thickness of the lamina is in range of tens of nanometers) was prepared from inorganic titanium compounds by hydrothermal reactions at 433 K. Ag(2)O nanocrystals (5-30 nm) were deposited onto the titanate lamina. The surface of the titanate lamina has crystallographic similarity to that of Ag(2)O nanocrystals. Hence, the deposited Ag(2)O nanocrystals and titanate substrate join together at these surfaces, forming a well-matched phase coherent interface between them. Such coherence between the two phases reduces the overall energy by minimizing surface energy and anchors the Ag(2)O nanocrystals firmly on the external surface of the titanate structure. The composite thus obtained was applied as efficient adsorbent to remove radioactive iodine from water (one gram adsorbent can capture up to 3.4 mmol of I(-) anions). The composite adsorbent can be recovered easily for safe disposal. The structure changes of the titanate lamina and the composite adsorbent were monitored by various techniques. The isotherm and kinetics of iodine adsorption, competitive adsorption and column adsorption using the adsorbent were studied to assess its iodine removal abilities. The adsorbent exhibited a capacity as high as 3.4 mmol of iodine per gram of adsorbent in 1h. Therefore, Ag(2)O deposited titanate lamina is an effective adsorbent for removing radioactive iodine from water.