General Strategy For Synthesis Research Articles

Amorphous Bimetallic Oxide-Graphene Hybrids as Bifunctional Oxygen Electrocatalysts for Rechargeable Zn-Air Batteries.

Metal oxides of earth-abundant elements are promising electrocatalysts to overcome the sluggish oxygen evolution and oxygen reduction reaction (OER/ORR) in many electrochemical energy-conversion devices. However, it is difficult to control their catalytic activity precisely. Here, a general three-stage synthesis strategy is described to produce a family of hybrid materials comprising amorphous bimetallic oxide nanoparticles anchored on N-doped reduced graphene oxide with simultaneous control of nanoparticle elemental composition, size, and crystallinity. Amorphous Fe0.5 Co0.5 Ox is obtained from Prussian blue analog nanocrystals, showing excellent OER activity with a Tafel slope of 30.1 mV dec-1 and an overpotential of 257 mV for 10 mA cm-2 and superior ORR activity with a large limiting current density of -5.25 mA cm-2 at 0.6 V. A fabricated Zn-air battery delivers a specific capacity of 756 mA h gZn-1 (corresponding to an energy density of 904 W h kgZn-1 ), a peak power density of 86 mW cm-2 and can be cycled over 120 h at 10 mA cm-2 . Other two amorphous bimetallic, Ni0.4 Fe0.6 Ox and Ni0.33 Co0.67 Ox , are also produced to demonstrate the general applicability of this method for synthesizing binary metal oxides with controllable structures as electrocatalysts for energy conversion.

Precise Engineering of Nanocrystal Shells via Colloidal Atomic Layer Deposition

We present a general strategy for a facile synthesis of complex multifunctional nanoscale materials via colloidal atomic layer deposition (c-ALD). The c-ALD technique is based on self-limiting half-reactions of ionic precursors on the surface of a nanocrystal (NC) occurring at room temperature. Using this technique, uniform layers of CdS and ZnS semiconductor shells were epitaxially grown on CdSe semiconductor cores with different shell combinations, leading to the precise control of the optical properties of these heterostructures. All core–shell multicomponent nanoparticles preserve narrow size distributions, phase crystallinity, and shape homogeneity of the initial NCs. Furthermore, we attempted to extend the toolbox of the c-ALD to combine materials with intrinsically different properties, such as Au/CdS core/shell structures with substantial lattice mismatch. The results presented in this work demonstrate great opportunities for creating functional materials with programmable properties for electroni...

A general strategy for template-free and low-cost synthesis of inorganic hollow spheres

Inorganic hollow spheres have a great potential in many fields, such as calcium phosphate (Ca3(PO4)2) as carriers of active ingredients and local delivery. They are typically synthesized by the methods that reply on template-based strategies. However, the template residue and energy consumption during template removal are drawbacks. Currently developed template-free methods remain challenges such as time, cost and complicated procedures. In this paper, we introduce a general low-cost and template-free precipitation method with simple procedure. A series of inorganic hollow spheres, including calcium phosphate, calcium fluoride, strontium phosphate, strontium fluoride, barium phosphate and barium fluoride via magnesium were successfully synthesized, respectively. Based on these experimental results, a new model is proposed to explain the mechanism of the hollow inorganic spheres formation. This paper provides a general method to synthesize inorganic hollow spheres, which may have an important indication to other systems.

Cluster Preface: Asymmetric Brønsted Base Catalysis

Choon-Hong Tan is a professor at the Division of Chemistry and Biological Chemistry, Nanyang Technological University, Singapore. He received his BSc (Hons) First Class from the National University of Singapore (NUS) and his Phd from the University of Cambridge. He underwent postdoctoral training at the Department of Chemistry and Chemical Biology, Harvard University and the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School. He began his independent career at the Department of Chemistry, National University of Singapore in 2003. Choon Hong has focused on the development of organocatalytic Brønsted base reactions that can be catalyzed with chiral guanidines. He has also demonstrated that pentanidiums (conjugated guanidiniums) are efficient phase-transfer catalysts. Recently, he described the use of chiral organic cations such as bisguanidiniums to modulate and activate anionic metallic salts. Benjamin List has been a director at the Max-Planck-Institut für Kohlenforschung since 2005. He obtained his Ph.D. in 1997 (Frankfurt). From 1997 until 1998 he conducted postdoctoral research at The Scripps Research Institute in La Jolla (USA) and became an assistant professor there in January 1999. In 2003 he joined the Max-Planck-Institut für Kohlenforschung. He has been an honorary professor at the University of Cologne since 2004. Ben List’s research focuses on organic synthesis and catalysis. He has contributed fundamental concepts to chemical synthesis including aminocatalysis, enamine catalysis, and asymmetric-counteranion-directed catalysis (ACDC). His latest work deals with chiral counteranions in asymmetric catalysis. This remarkably general strategy for asymmetric synthesis has recently found widespread use in organocatalysis, transition-metal catalysis, and Lewis acid catalysis.

General Strategy for the Synthesis of Transition-Metal Phosphide/N-Doped Carbon Frameworks for Hydrogen and Oxygen Evolution.

Transition metal phosphides (TMPs) have been identified as promising nonprecious metal electrocatalyst for hydrogen evolution reaction (HER) and other energy conversion reactions. Herein, we reported a general strategy for synthesis of a series of TMPs (Fe2P, FeP, Co2P, CoP, Ni2P, and Ni12P5) nanoparticles (NPs) with different metal phases embedded in a N-doped carbon (NC) matrix using metal salt, ammonium dihydrogen phosphate, and melamine as precursor with varying molar ratios and thermolysis temperatures. The resultant TMPs can serve as highly active and durable bifunctional electrocatalyst toward HER and oxygen evolution reaction (OER). In particular, the Ni2P@NC phase only requires an overpotential of ∼138 mV to derive HER in 0.5 M H2SO4, and ∼320 mV for OER in 1.0 M KOH at the current density of 10 mA cm-2. Because of the encapsulation of NC that can effectively prevent corrosion of embedded TMP NPs, Ni2P@NC exhibits almost unfading catalytic performance even after 10 h under both acidic and alkaline solutions. This synthesis strategy provides a new avenue to exploring TMPs as highly active and stable electrocatalyst for the HER, OER, and other electrochemical applications.

Holey two-dimensional transition metal oxide nanosheets for efficient energy storage

Transition metal oxide nanomaterials are promising electrodes for alkali-ion batteries owing to their distinct reaction mechanism, abundant active sites and shortened ion diffusion distance. However, detailed conversion reaction processes in terms of the oxidation state evolution and chemical/mechanical stability of the electrodes are still poorly understood. Herein we explore a general synthetic strategy for versatile synthesis of various holey transition metal oxide nanosheets with adjustable hole sizes that enable greatly enhanced alkali-ion storage properties. We employ in-situ transmission electron microscopy and operando X-ray absorption structures to study the mechanical properties, morphology evolution and oxidation state changes during electrochemical processes. We find that these holey oxide nanosheets exhibit strong mechanical stability inherited from graphene oxide, displaying minimal structural changes during lithiation/delithiation processes. These holey oxide nanosheets represent a promising material platform for in-situ probing the electrochemical processes, and could open up opportunities in many energy storage and conversion systems.

Facile synthesis, dielectric properties and electrocatalytic activities of PMMA-NiFe2O4 nanocomposite

The paper deals with the dielectric and catalytic properties of poly (methyl methacrylate)-nikel ferrite (PMMA-NiFe2O4) nanocomposite. The nanocomposite was prepared by using a general and facile synthesis strategy. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectra confirmed the formation of PMMA-NiFe2O4 nanocomposite. Field effect scanning electron microscopic (FESEM) and transmission electron microscopic (TEM) images revealed that NiFe2O4 nanoparticles were uniformly distributed and were tightly adhered with PMMA matrix owing to surface modification with 3-methacryloyloxy propyl trimethoxy silane (KH-570). Thermal stability was enhanced by incorporation of NiFe2O4 nanofillers. The nanocomposite showed high dielectric constant and low dielectric loss. The achieved dielectric and thermal property inferred the potential application of this material in energy storage and embedded electronics devices. Further, the as prepared nanocomposite also offered a remarkable electrochemical performance towards hydrogen peroxide (H2O2) sensing.

A Top‐Down Strategy toward 3D Carbon Nanosheet Frameworks Decorated with Hollow Nanostructures for Superior Lithium Storage

Graphene has shown great potential in vast fields due to the unique structure and properties, but its practical application is still hindered by high cost and scarcity in supply. The development of low‐cost substitute of graphene is thus highly desired to meet the practical demand of upcoming applications where extremely physical properties are not absolutely critical. In this work, a top‐down strategy for general synthesis of 3D carbon nanosheet frameworks decorated with metal nanoparticles by a metal nitrate‐assisted polymer‐blowing process is reported. Such architecture provides a promising structural platform for the fabrication of carbon nanosheet frameworks functionalized with metal oxide or carbon hollow nanostructures through subsequent chemical conversion. The unique structures impart intimate structural interconnectivities, highly opened freeway for ionic diffusion, large accessible surface area, as well as high structural stability, opening up a wide horizon for electrochemical applications, for example, high‐energy, long‐life lithium‐ion batteries and lithium–sulfur batteries highlighted in this work.

A Stable Extra-Large-Pore Zeolite with Intersecting 14- and 10-Membered-Ring Channels.

The development of inorganic frameworks with extra-large pores (larger than 12-membered rings) has attracted considerable attention because of their potential applications in catalysis, the separation of large molecules, and so forth. We herein report the synthesis of the new extra-large-pore zeolite NUD-2 by using the supramolecular self-assembly of simple aromatic organic cations as structure-directing agents (SDAs). NUD-2 is a high-silicon-content germanosilicate with interconnecting 14×10-membered-ring channels. The SDAs in NUD-2 can be removed by calcination in air at 550 °C to yield permanent pores with a BET surface area of 500 m(2) g(-1) . Both germanium and organic cations in NUD-2 can also be removed by treatment with acid at lower temperature, thus not only affording recycling of germanium and SDAs, but also providing a highly stable siliceous zeolite. In addition, aluminum ions can be incorporated into the framework of NUD-2. The NUD-2 structure is yet another extra-large-pore zeolite synthesized by using the supramolecular self-assembling templating approach, thus demonstrating that this approach is a general and applicable strategy for synthesis of new large- and extra-large-pore zeolites.

Acridinium Ester-Functionalized Carbon Nanomaterials: General Synthesis Strategy and Outstanding Chemiluminescence.

In this work, three different kinds of acridinium ester (AE)-functionalized carbon nanomaterials, including AE-functionalized carbon nanoparticles (AE-CNPs), AE-functionalized graphene oxide (AE-GO), and AE-functionalized multiwalled carbon nanotubes (AE-MCNTs), were synthesized for the first time via a simple, general, and noncovalent strategy. AE molecules were assembled on the surface of carbon nanomaterials by electrostatic interaction, π-π stacking interaction, and amide bond. The synthesized AE-CNPs, AE-GO, and AE-MCNTs with 5.0 × 10(-8) mol·L(-1) of synthetic AE concentration, which was very low compared with other chemiluminescence (CL) reagents such as luminol, N-(aminobutyl)-N-(ethylisoluminol), and lucigenin at the concentration of 3.3 × 10(-4) to 5.0 × 10(-6) mol·L(-1) used for the synthesis of CL-functionalized nanomaterials, exhibited outstanding CL activity and good stability. It was found that carbon nanomaterials as nanosized platforms could efficiently immobilize AE molecules and facilitate the formation of OH(•) and O2(•-), leading to strong light emission. Moreover, the CL intensity of AE-GO was the highest, which was about 8.7 and 3.7 times higher than that of AE-CNPs and AE-MCNTs, respectively. This mainly resulted from a difference in the amount of adsorbed AE molecules on the surface of different carbon nanomaterials. Additionally, the prepared AE-CNPs demonstrated excitation-dependent fluorescence property and good fluorescence stability against photobleaching. On the basis of the excellent CL and special fluorescence properties of AE-CNPs, a dual-mode array strategy has been proposed for the first time and seven kinds of transition-metal ions could be successfully discriminated.

Highly Ordered Hierarchical Macroporous-Mesoporous Alumina with Crystalline Walls

Highly ordered hierarchical macroporous-mesoporous alumina with crystalline walls are synthesized by facial route. The general synthesis strategy is based on a sol–gel process associated with block copolymers as soft templates and polystyrene colloidal crystals as hard template to produce macropore and mesopore structures, respectively. Small-angle XRD, TEM and Nitrogen adsorption and desorption results show that hierarchical macroporous-mesoporous alumina possess highly ordered two-dimensional hexagonal mesostructured and highly ordered face centered cubic macropore arrays structure. The present work reveals that the hierarchical macroporous-mesoporous structure can endure high temperature up to 900 °C. FTIR pyridine adsorption measurements show that the amount of Lewis acid sites provided by hierarchical macroporous-mesoporous alumina is nearly two times more than that for mesoporous alumina, indicating that the open macroporous structure may be in favor of the reactant transfer, and the consequently superior activity. Large surface areas, high thermal stability, uniform pore structures and large amounts of surface Lewis acid sites illustrate that these materials are expected to find wide applications in catalysis realm. The highly ordered hierarchical macroporous-mesoporous alumina with crystalline walls are synthesized by a sol–gel process associated with block copolymers as soft templates and polystyrene colloidal crystals as hard template to produce macropore and mesopore structures, respectively.

A General Synthesis Strategy for Highly Dispersed Amorphous MoO3 over Supported Catalysts

AbstractAmorphous MoO3 was evenly deposited on a Bi2SiO5/SiO2 support by a strategy of heterogenous coprecipitation using Ti as structural promoter. The structure and properties of MoO3‐Bi2SiO5/SiO2 have been characterized by a series of techniques, including N2 adsorption/desorption analysis, X‐ray diffraction (XRD), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS) and ultraviolet‐visible light (UV‐vis) diffuse reflectance spectra (DRS).The addition of n‐butyl alcohol into synthesis medium resulted in the most dispersive amorphous MoO3, with an average particle size of 4 nm. Selective oxidation of propylene was chosen as a probe reaction to test the performance of catalysts. Kinetic study revealed that the method of heterogeneous coprecipitation enhanced catalytic performance via increasing the number of active sites, rather than changing the nature of it. This is well compatible with characterization results.

Freeze-drying of "pearl milk tea": A general strategy for controllable synthesis of porous materials.

Porous materials have been widely used in many fields, but the large-scale synthesis of materials with controlled pore sizes, pore volumes, and wall thicknesses remains a considerable challenge. Thus, the controllable synthesis of porous materials is of key general importance. Herein, we demonstrate the “pearl milk tea” freeze-drying method to form porous materials with controllable pore characteristics, which is realized by rapidly freezing the uniformly distributed template-containing precursor solution, followed by freeze-drying and suitable calcination. This general and convenient method has been successfully applied to synthesize various porous phosphate and oxide materials using different templates. The method is promising for the development of tunable porous materials for numerous applications of energy, environment, and catalysis, etc.

ChemInform Abstract: General Homologation Strategy for Synthesis of L‐glycero‐ and D‐glycero‐Heptopyranoses.

AbstractVarious title compounds are prepared following the sequence shown for example (V).

Fmoc solid-phase synthesis of C-terminal modified peptides by formation of a backbone cyclic urethane moiety.

C-terminally modified peptides are of high significance due to the therapeutic properties that accompany various C-terminal functional groups and the ability to manipulate them for further applications. Thus, there is a great necessity for an effective solid phase technique for the synthesis of C-terminally modified peptides. Here, we report a universal solid phase strategy for the synthesis of various C-terminal modified peptides which is independent of the type of resins, linkers, and unnatural moieties typically needed for C-terminal modifications. The technique proceeds by the modification of C-terminal serine to a cyclic urethane moiety which results in the activation of the backbone amide chain for nucleophilic displacement by various nucleophiles to generate C-terminally modified acids, esters, N-aryl amides, and alcohols. This cyclic urethane technique (CUT) also provides a general strategy for synthesis of C-terminal protected peptides that can be used for convergent synthesis of large peptides. The C-terminal protecting groups are cleaved by facile hydrolysis to release the free peptide.

Geert‐Jan Boons

Angewandte Chemie International EditionVolume 55, Issue 14 p. 4392-4392 Author ProfileFree Access Geert-Jan Boons First published: 23 November 2015 https://doi.org/10.1002/anie.201510191AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract “My favorite author (fiction) is Louis Paul Boon. The downside of my job is spending too much time away from home ...” This and more about Geert-Jan Boons can be found on page 4392. 1 Table 1. Geert-Jan Boons Date of birth: April 7, 1962 Position: UGA Foundation Distinguished Professor in Biochemical Sciences, Department of Chemistry and the Complex Carbohydrate Research Center, University of Georgia; Professor and Chair of the Department of Medicinal and Biological Chemistry, Utrecht University E-mail: gjboons@ccrc.uga.edu Homepage: http://cell.ccrc.uga.edu/∼gjboons/boons/Home.htm Education: 1997 MSc, Leiden University 1991 PhD supervised by Prof. Dr. J. H. van Boom, Leiden University 1991–1993 Ramsay Memorial Fellow with Prof. Dr. S. V. Ley, Imperial College, London, and University of Cambridge Awards: 2003 Carbohydrate Research Award for Creativity in Carbohydrate Chemistry, International Carbohydrate Association (ICO); 2004 Horace Isbell Award, American Chemical Society (ACS); 2014 Roy L. Whistler International Award in Carbohydrate Chemistry, ICO; 2015 Hudson Award, ACS; 2016 Arthur C. Cope Scholar Award, ACS Current research Glycoscience, synthetic vaccine and immune modulators, bioorthogonal chemistry, molecular recognition Hobbies: Cooking, reading, dog training, bee keeping My favorite author (fiction) is Louis Paul Boon. The downside of my job is spending too much time away from home. My favorite motto is “with a little bit of luck”. The biggest problem that scientists face is administrators. If I won the lottery, I would give it all away. When I'm frustrated, I go for a walk with my dogs. My favorite place on earth is home. If I were not a scientist, I would be a chef. My most exciting discovery to date has been to break immune tolerance against tumor-associated carbohydrate antigens with a fully synthetic vaccine. My greatest achievement has been training students who eventually will start their own independent career. My 5 top papers: References 1“Visualizing Metabolically Labeled Glycoconjugates of Living Cells by Copper-Free and Fast Huisgen Cycloadditions”: X. Ning, J. Guo, M. A. Wolfert, G. J. Boons, Angew. Chem. Int. Ed. 2008, 47, 2253; Wiley Online LibraryCASPubMedWeb of Science®Google ScholarAngew. Chem. 2008, 120, 2285. (A reagent that reacts exceptionally fast with azido-containing biomolecules.) Wiley Online LibraryGoogle Scholar 2“Modular Synthesis of Heparan Sulfate Oligosaccharides for Structure–Activity Relationship Studies”: S. Arungundram, K. Al-Mafraji, J. Asong, F. E. Leach III, I. J. Amster, A. Venot, J. E. Turnbull, G. J. Boons, J. Am. Chem. Soc. 2009, 131, 17394. (Allows the preparation of well-defined heparan sulfate oligosaccharide libraries.) CrossrefCASPubMedWeb of Science®Google Scholar 3“Chiral auxiliary mediated 1,2-cis-glycosylations for the solid supported synthesis of a biologically important branched α-glucan”: T. J. Boltje, J.-H. Kim, J. Park, G. J. Boons, Nat. Chem. 2010, 2, 552. (A combination of classical and auxiliary-mediated neighboring-group participation for controlling anomeric selectivities.) CrossrefCASPubMedWeb of Science®Google Scholar 4“Immune recognition of tumor-associated mucin MUC1 is achieved by a fully synthetic aberrantly glycosylated MUC1 tripartite vaccine”: V. Lakshminarayanan, P. Thompson, M. A. Wolfert, T. Buskas, J. M. Bradley, L. B. Pathangey, C. S. Madsen, P. A. Cohen, S. J. Gendler, G. J. Boons, Proc. Natl. Acad. Sci. U.S.A. 2012, 109, 261. (The vaccine was efficacious in reversing tolerance and generating a therapeutic response in a mouse model for breast cancer.) CrossrefCASPubMedWeb of Science®Google Scholar 5“A General Strategy for the Chemoenzymatic Synthesis of Asymmetrically Branched N-Glycans”: Z. Wang, Z. S. Chinoy, S. G. Ambre, W. Peng, R. McBride, R. P. de Vries, J. Glushka, J. C. Paulson, G. J. Boons, Science 2013, 341, 379. (The preparation of full cellular glycomes to investigate the specificities and biology of glycan-binding proteins.) CrossrefCASPubMedWeb of Science®Google Scholar Volume55, Issue14March 24, 2016Pages 4392-4392 ReferencesRelatedInformation

A General Strategy for Synthesis of Heterocyclic Hemiketal‐Containing α,β‐Unsaturated Ketones from Ynediones

AbstractA general strategy for synthesis of heterocyclic hemiketal‐containing α,β‐unsaturated ketones has been established. Using the environmentally sound and readily available reagents water and thiourea applied to ynediones, a series of sensitive hemiketals of 3(2 H)‐furanones and 3(2 H)‐thienones were constructed under mild conditions. Both of the reaction conditions are compatible with a diverse range of functional groups. Isotopic labeling, tautomerism, and GC‐MS tracking methods were used to reveal the mechanisms.

ChemInform Abstract: Effective Recognition of Different Types of Amino Groups: From Aminobenzenesulfonamides to Amino‐(N‐alkyl)benzenesulfonamides via Iridium‐Catalyzed N‐Alkylation with Alcohols.

ChemInformVolume 46, Issue 38 Isocyclic Compounds ChemInform Abstract: Effective Recognition of Different Types of Amino Groups: From Aminobenzenesulfonamides to Amino-(N-alkyl)benzenesulfonamides via Iridium-Catalyzed N-Alkylation with Alcohols. Lei Lu, Lei Lu Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this authorJuan Ma, Juan Ma Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this authorPanpan Qu, Panpan Qu Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this authorFeng Li, Feng Li Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this author Lei Lu, Lei Lu Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this authorJuan Ma, Juan Ma Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this authorPanpan Qu, Panpan Qu Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this authorFeng Li, Feng Li Key Lab. Soft Chem. Funct. Mater., Nanjing Univ. Sci. Technol., Nanjing 210094, Peop. Rep. ChinaSearch for more papers by this author First published: 03 September 2015 https://doi.org/10.1002/chin.201538092Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume46, Issue38September, 2015 RelatedInformation

Honeycomb-like Porous Carbon–Cobalt Oxide Nanocomposite for High-Performance Enzymeless Glucose Sensor and Supercapacitor Applications

Herein, we report the preparation of Pongam seed shells-derived activated carbon and cobalt oxide (∼2-10 nm) nanocomposite (PSAC/Co3O4) by using a general and facile synthesis strategy. The as-synthesized PSAC/Co3O4 samples were characterized by a variety of physicochemical techniques. The PSAC/Co3O4-modified electrode is employed in two different applications such as high performance nonenzymatic glucose sensor and supercapacitor. Remarkably, the fabricated glucose sensor is exhibited an ultrahigh sensitivity of 34.2 mA mM(-1) cm(-2) with a very low detection limit (21 nM) and long-term durability. The PSAC/Co3O4 modified stainless steel electrode possesses an appreciable specific capacitance and remarkable long-term cycling stability. The obtained results suggest the as-synthesized PSAC/Co3O4 is more suitable for the nonenzymatic glucose sensor and supercapacitor applications outperforming the related carbon based modified electrodes, rendering practical industrial applications.

Self-Template Synthesis of Porous Perovskite Titanate Solid and Hollow Submicrospheres for Photocatalytic Oxygen Evolution and Mesoscopic Solar Cells

We describe a general synthesis strategy, which combines sol-gel and hydrothermal processes, for the large-scale synthesis of porous perovskite titanates spheres with tunable particle size and inner structures. Amorphous hydrous TiO2 solid spheres (AHTSS) are first synthesized by a sol-gel method and are then used as precursor and template for the subsequent hydrothermal reaction with alkaline earth metal ions in an alkaline medium. This strategy can be generalized to synthesize porous spheres of various perovskite titanates (i.e., SrTiO3, BaTiO3, and CaTiO3) consisting of single-crystalline nanocubes. By controlling the textural properties (i.e., size, porosity, and structure) of AHTSS, perovskite titanates with tunable size and inner structures are selectively synthesized. The underlying formation mechanism is manifested by XRD and TEM to involve in situ crystallization or Ostwald ripening during the hydrothermal process. The obtained porous SrTiO3 spheres present superior performance in photocatalytic oxygen evolution and CdSe-sensitized mesoscopic solar cells.