Publications (116)885.14 Total impact
-
Article: Coassembly between the Largest and Smallest Metal Chalcogenide Supertetrahedral Clusters.
[show abstract] [hide abstract]
ABSTRACT: Reported here is the first crystalline inorganic-organic hybrid material combining In, Ge, and Cu. The trimetallic system undergoes a nanoscale separation into small In-Ge-S supertetrahedral T2 clusters and large In-Cu-S T5 clusters, which are further assembled into a T2-T5 mixed layer. This material reveals the long-range crystallographically ordered assembly from supertetrahedral clusters with 3 orders of difference, the largest size mismatch known so far for mixed-supertetrahedral-cluster materials. Theoretical simulations were performed to probe the contribution to the band structure by the different-sized semiconducting clusters.Inorganic Chemistry 03/2013; 52(5):2259-61. · 4.60 Impact Factor -
Article: Boron Carbides as Efficient, Metal-Free, Visible-Light-Responsive Photocatalysts.
[show abstract] [hide abstract]
ABSTRACT: From Armor Plating to Photocatalysis: Two photocatalysts based on boron carbides, B(4.3) C and B(13) C(2) , are reported. The more stable and efficient B(4.3) C exhibits H(2) evolution rates of about two orders of magnitude higher than graphitic C(3) N(4) , and without the need for noble metal cocatalysts. Also, both materials can act as photocathodes for photoelectrochemical water reduction under visible light irradiation.Angewandte Chemie International Edition 01/2013; · 13.45 Impact Factor -
Article: Facile Synthesis of Thermal- and Photostable Titania with Paramagnetic Oxygen Vacancies for Visible-Light Photocatalysis.
[show abstract] [hide abstract]
ABSTRACT: A novel dopant-free TiO(2) photocatalyst (V(o) (.) -TiO(2) ), which is self-modified by a large number of paramagnetic (single-electron-trapped) oxygen vacancies, was prepared by calcining a mixture of a porous amorphous TiO(2) precursor, imidazole, and hydrochloric acid at elevated temperature (450 °C) in air. Control experiments demonstrate that the porous TiO(2) precursor, imidazole, and hydrochloric acid are all necessary for the formation of V(o) (.) -TiO(2) . Although the synthesis of V(o) (.) -TiO(2) originates from such a multicomponent system, this synthetic approach is facile, controllable, and reproducible. X-ray diffraction, XPS, and EPR spectroscopy reveal that the V(o) (.) -TiO(2) material with a high crystallinity embodies a mass of paramagnetic oxygen vacancies, and is free of other dopant species such as nitrogen and carbon. UV/Vis diffuse-reflectance spectroscopy and photoelectrochemical measurement demonstrate that V(o) (.) -TiO(2) is a stable visible-light-responsive material with photogenerated charge separation efficiency higher than N-TiO(2) and P25 under visible-light irradiation. The V(o) (.) -TiO(2) material exhibits not only satisfactory thermal- and photostability, but also superior photocatalytic activity for H(2) evolution (115 μmol h(-1) g(-1) ) from water with methanol as sacrificial reagent under visible light (λ>400 nm) irradiation. Furthermore, the effects of reaction temperature, ratio of starting materials (imidazole:TiO(2) precursor) and calcination time on the photocatalytic activity and the microstructure of V(o) (.) -TiO(2) were elucidated.Chemistry 01/2013; · 5.93 Impact Factor -
Article: A Three-Dimensional Branched Cobalt-Doped α-Fe(2) O(3) Nanorod/MgFe(2) O(4) Heterojunction Array as a Flexible Photoanode for Efficient Photoelectrochemical Water Oxidation.
[show abstract] [hide abstract]
ABSTRACT: Hitting water with nanotrees: A three-dimensional branched heterojunction array for water oxidation based on cobalt-doped α-Fe(2) O(3) nanorod cores and MgFe(2) O(4) shells has been successfully synthesized. Such an architecture not only has a large surface area and excellent light absorption properties, and shows fast charge transport, but also exhibits a very high photoelectrochemical activity for water oxidation and a high stability.Angewandte Chemie International Edition 12/2012; · 13.45 Impact Factor -
Article: Visible-Light-Driven α-Fe2O3 Nanorod/Graphene/BiV1-xMoxO4 Core/Shell Heterojunction Array for Efficient Photoelectrochemical Water Splitting.
[show abstract] [hide abstract]
ABSTRACT: We report the design, synthesis and characterization of a novel heterojunction array of α-Fe2O3/graphene/BiV1-xMoxO4 core/shell nanorod for photoelectrochemical water splitting. The heterojunction array was prepared by hydrothermal deposition of α-Fe2O3 nanorods onto Ti substrate, with subsequent coating of graphene interlayer and BiV1-xMoxO4 shell by photocatalytic reduction and a spin-coating approach, respectively. The heterojunction yielded a pronounced photocurrent density of ∼ 1.97 mA/cm2 at 1.0 V vs. Ag/AgCl, and a high photoconversion efficiency of ∼ 0.53% at -0.04 V vs. Ag/AgCl under the irradiation of a Xe lamp. The improved photoelectrochemical properties benefited from (1) the enhanced light absorption due to behavior of the "window effect" between the α-Fe2O3 cores and BiV1-xMoxO4 shells, and (2) the improved separation of photogenerated carriers at the α-Fe2O3 nanorod/graphene/BiV1-xMoxO4 interface. Our results demonstrate the advantages of the novel graphene-mediated core/shell heterojunction array, and provide a valuable insight for the further development of such materials.Nano Letters 11/2012; · 13.20 Impact Factor -
Article: Generalized synthesis of zeolite-type metal-organic frameworks encapsulating immobilized transition-metal clusters.
[show abstract] [hide abstract]
ABSTRACT: Zeolites are generally made from tetrahedral nodes and ditopic linkers. Reported here is a versatile method based on trifunctional ligands. With this method, two functional groups are used to form zeolitic nets, while the third one serves to immobilize metal clusters within the channels. The process is driven by the coexistence of multiple inorganic building blocks generated in the heterometallic system. The generality of this method is shown by three distinct metal-organic frameworks mimicking AlPO(4)-5 (AFI) and BCT zeotypes as well as the cubic lcs topology. The correlation between the framework topology and trapped metal species reveals the unique bidirectional control (framework topology ↔ confined metal species) that may be exploited to create a large family of zeotypes with channels modified by different metal ions and clusters.Journal of the American Chemical Society 07/2012; 134(29):11936-9. · 9.91 Impact Factor -
Article: Two zeolite-type frameworks in one metal-organic framework with Zn24 @Zn104 cube-in-sodalite architecture.
[show abstract] [hide abstract]
ABSTRACT: Two in one: A metal-organic framework obtained from three different inorganic building blocks (tetrameric Zn(4) O, trimeric Zn(3) OH, and monomeric Zn) posseses a nested cage-in-cage and framework-in-framework architecture. 24 Zn(4) O tetramers and eight Zn monomers form a sodalite cage into which a cubic cage made from eight Zn(3) (OH) trimers is nestled. Eight monomeric Zn(2+) centers interconnect these two cages.Angewandte Chemie International Edition 07/2012; 51(34):8538-41. · 13.45 Impact Factor -
Article: Assembly of super-supertetrahedral metal-organic clusters into a hierarchical porous cubic framework.
[show abstract] [hide abstract]
ABSTRACT: A porous framework comprising a super-supertetrahedral metal-organic cluster building block has been synthesized. Its cubic framework represents a multi-level hierarchical architecture and also possesses an interesting magnetic property.Chemical Communications 06/2012; 48(60):7498-500. · 6.17 Impact Factor -
Article: Active facets on titanium(III)-doped TiO2: an effective strategy to improve the visible-light photocatalytic activity.
[show abstract] [hide abstract]
ABSTRACT: Partially reduced TiO(2) with highly active facets has been fabricated: Ti(3+) was successfully incorporated without any additional reducing agent and surfactant, and highly active facets developed preferentially. The product shows improved photocatalytic activity in H(2) production over previously reported material. Photocatalytic activity over an extended time period demonstrates the stability of reduced TiO(2) made by this approach.Angewandte Chemie International Edition 05/2012; 51(25):6223-6. · 13.45 Impact Factor -
Article: Induction of trimeric [Mg3(OH)(CO2)6] in a porous framework by a desymmetrized tritopic ligand.
[show abstract] [hide abstract]
ABSTRACT: The use of a desymmetrized tritopic ligand with both carboxyl and pyridyl functionalities leads to the first occurrence of the [Mg(3)(μ(3)-OH)(CO(2))(6)] trimer as the 3-D framework building block in a porous crystal that shows relatively high H(2) uptake (1.37% at 77 K and 1 atm).Dalton Transactions 03/2012; 41(10):2866-8. · 3.84 Impact Factor -
Article: A twelve-connected porous framework built from rare linear cadmium tricarboxylate pentamer.
[show abstract] [hide abstract]
ABSTRACT: A twelve-connected 3D metal-organic framework built from a rare linear Cd(5)(COOR)(12) pentamer with selective CO(2) uptake, has been prepared and characterized, together with a 2D framework based on a shorter linear Cd(3)(COOR)(6) trimer.Dalton Transactions 03/2012; 41(13):3620-2. · 3.84 Impact Factor -
Article: Superbase route to supertetrahedral chalcogenide clusters.
[show abstract] [hide abstract]
ABSTRACT: Supertetrahedral Tn clusters are exact fragments of a cubic ZnS type lattice. Thus far, Tn clusters up to T4 with 20 metal sites can be synthesized in a discrete molecular form. Yet, synthesis of larger discrete supertetrahedral clusters still remains a great challenge, likely due to the rapidly increasing negative charge on the cluster as the size goes up. By using organic superbases (DBN and DBU) to help stabilize the negative charge, a family of discrete supertetrahedral chalcogenide clusters with sizes spanning from T3 (10 metal sites) to T5 (35 metal sites) have been made. The T5 cluster represents the largest molecular supertetrahedral Tn cluster known to date.Journal of the American Chemical Society 02/2012; 134(8):3619-22. · 9.91 Impact Factor -
Article: Development of composite inorganic building blocks for MOFs.
[show abstract] [hide abstract]
ABSTRACT: A general direction for diversifying metal-organic frameworks (MOFs) is demonstrated by the synthesis of composite inorganic clusters between indium and s-, d-, and f-block elements. These previously unknown heterometallic clusters, with various nuclearity, geometry, charge, and metal-to-metal ratios, significantly expand the pool of inorganic building blocks that are highly effective for the construction of porous MOFs with high gas uptake capacity.Journal of the American Chemical Society 02/2012; 134(10):4517-20. · 9.91 Impact Factor -
Article: Mimicking zeolite to its core: porous sodalite cages as hangers for pendant trimeric M3(OH) clusters (M = Mg, Mn, Co, Ni, Cd).
[show abstract] [hide abstract]
ABSTRACT: A new class of zeolite-type porous materials in which 3D frameworks are covalently functionalized with crystallographically ordered pendant metal clusters have been synthesized. This work demonstrates a new paradigm for and the feasibility of functionalizing zeolite-type frameworks through the conversion of extraframework sites in mineral zeolites into part of the framework for occupation by dangling metal clusters in metal-organic frameworks.Journal of the American Chemical Society 02/2012; 134(4):1934-7. · 9.91 Impact Factor -
Article: Single-walled polytetrazolate metal-organic channels with high density of open nitrogen-donor sites and gas uptake.
[show abstract] [hide abstract]
ABSTRACT: The self-assembly between zinc dimer and 1,3,5-tris(2H-tetrazol-5-yl)benzene (H(3)BTT), promoted by a urea derivative, leads to a highly porous 3D framework with a large percentage (67%) of N-donor sites unused for bonding with metals. The material exhibits high gas storage capacity (ca. 1.89 wt % H(2) at 77 K and 1 atm; 98 cm(3)/g CO(2) at 273 K and 1 atm), even in the absence of open metal sites. The high percentage of open N-donor sites, coupled with the low framework density resulting from single-walled channels, is believed to contribute to the high uptake capacity.Journal of the American Chemical Society 01/2012; 134(2):784-7. · 9.91 Impact Factor -
Article: Lithium cubane clusters as tetrahedral, square planar, and linear nodes for supramolecular assemblies.
[show abstract] [hide abstract]
ABSTRACT: The use of bifunctional ligands with phenol and pyridyl groups has been found to promote the formation of lithium cubane clusters intrinsically coded with specific preference for various hydrogen-bonding geometries including tetrahedral, square-planar, and linear modes through double, or even quadruple hydrogen bonding between adjacent nodes.Dalton Transactions 12/2011; 41(14):3902-5. · 3.84 Impact Factor -
Article: A chiral tetragonal magnesium-carboxylate framework with nanotubular channels.
[show abstract] [hide abstract]
ABSTRACT: Reported here is a rare example of a highly symmetrical chiral Mg-based MOF (CPF-1) with nanotubular channels, built from 4(1) (or 4(3)) helical chains. It exhibits a high gas sorption capacity (ca. 1.29 wt% H(2) at 77 K, 1 atm; 84 cm(3) g(-1) of CO(2) at 273 K, 1 atm).Chemical Communications 11/2011; 47(43):11852-4. · 6.17 Impact Factor -
Article: A large indium sulfide supertetrahedral cluster built from integration of ZnS-like tetrahedral shell with NaCl-like octahedral core.
[show abstract] [hide abstract]
ABSTRACT: An entirely new type of chalcogenide cluster and a new structural mechanism for the formation of large semiconducting tetrahedral clusters have been revealed as a result of crystallization of a templated indium sulfide consisting of an unprecedented cluster, In(38)S(65), which is the largest supertetrahedral cluster based on trivalent metal ions. At the core of this cluster is In(10)S(13), which can be considered as a fragment of the NaCl-type lattice. The In(10)S(13) cluster is coupled to four In(4)S(10) supertetrahedral T2 clusters and four In(3)S(3) hexagonal rings to give In(38)S(65), which is also the largest inorganic chalcogenide supertetrahedral cluster, superseding a supertetrahedral T5 cluster with only 35 metal sites.Journal of the American Chemical Society 09/2011; 133(40):15886-9. · 9.91 Impact Factor -
Article: Porous indium-organic frameworks and systematization of structural building blocks.
Angewandte Chemie International Edition 09/2011; 50(38):8858-62. · 13.45 Impact Factor -
Article: A mixed ligand route for the construction of tetrahedrally coordinated porous lithium frameworks.
[show abstract] [hide abstract]
ABSTRACT: Reported here are two 4-connected 3D frameworks based on monomeric lithium nodes, which are synthesized through a mixed ligand route. By combining a negatively charged imidazole ligand and a neutral bis(imidazolyl)methane ligand (or one of its derivatives), neutral frameworks adopting chiral quartz-dual and diamond topologies have been obtained. These materials have low framework density and can reversibly adsorb hydrogen gas.Dalton Transactions 08/2011; 40(32):8072-4. · 3.84 Impact Factor
Top co-authors
Top Journals
Institutions
-
2002–2013
-
University of California, Riverside
- Department of Chemistry
Riverside, CA, USA
-
-
2004–2012
-
California State University, Long Beach
- Department of Chemistry & Biochemistry
Long Beach, CA, USA
-
-
2004–2011
-
CSU Mentor
- Department of Chemistry and Biochemistry
Long Beach, CA, USA
-
-
1997–1998
-
University of California, Santa Barbara
- Department of Chemistry and Biochemistry
Santa Barbara, CA, USA
-
