Postdoctoral positions in inorganic, solid state and materials chemistry

From time to time, postdoctoral positions become available in this group. We are particularly interested in researchers with trainings and achievements in the following areas: metal-organic frameworks (MOFs), hydrogen storage, photocatalytic hydrogen production. Strong skills in crystal growth, hydro- or solvothermal synthesis, and structural analysis by X-ray diffraction are highly desirable. All applications should be sent to pingyun.feng@ucr.edu.

Research Overview

Crystalline Porous Materials

Microporous materials are typically crystalline oxides with uniform pore sizes from 3 to 20Å and mesoporous materials cover the pore size range from 20 to 500 Å. Our research in this area is aimed at developing new synthetic methodologies to generate nanoporous materials with unprecedented framework compositions, pore geometry and controllable morphology. The purpose is to find efficient heterogeneous catalysts for industrial chemical reactions or for energy related applications.

Porous chalcogenides possess structural properties characteristic of traditional porous materials such as zeolites, but they generally have better electrical and optical properties. The integration between unform microporosity and electrical/optical properties promises new opportunities in many applications. One interesting property that was recently found is the fast ionic conductivity in a series of hydrated sulfides and selenides. They may also serve as photocatalysts for the production of hydrogen from water (see below).

Synthesis and Organization of Semiconducting Clusters

Quantum confinement in size and dimension can lead to chemical, electrical, and optical properties that are substantially different from those observed for the bulk material. These new properties can lead to numerous technological applications. My research group is interested in exploring new synthetic methodologies to prepare nanoclusters with simultaneous control in size, surface features, and spatial arrangements from zero to three dimensions. We are particularly interested in crystalline nanoclusters with precisely defined compositions and sizes and in their superlattices with various connectivity. One of our recent successes in this area is the synthesis of the largest Cd-S cluster (by single crystal diffraction) containing as many as 54 metal sites.

Porous Semiconductors as Visible-Light Driven Photocatalyst

One important application of porous semiconductors is photocatalysis for the generation of hydrogen fuel from water using visible light. Such photocatalytic process can take advantage of the unique integration of crystalline microporosity and semiconductivity in porous semiconductors. The photocatalytic reduction of water to produce hydrogen fuel has been widely studied during the past several decades, however, nearly all these studies have been confined to condensed semiconductors. So far, efficient catalysts, particular those in visible-light region are rare. We have demonstrated that porous semiconducting chalcogenides can be highly efficient photocatalysts, particularly compared with traditional condensed semiconductors. Impressively, the high activity of these porous photocatalysts does not require the use of any co-catalyst such as Pt.

Selected Publications

• Chen, S.; Zhang, J.; Wu, T.; Feng, P.; Bu, X. Multi-Route Synthesis of Porous Anionic Frameworks and Size-Tunable Extra-framework Organic-Cation-Controlled Gas Sorption Properties, J. Am. Chem. Soc. 2009, 131, xxxx.

• Liu, R.; Zhang, Y.; Feng, P. Multi-responsive supramolecular nanogated ensembles, J. Am. Chem. Soc. 2009, 131, 15128.

• Wu, T.; Wang, X.; Bu,X.; Zhao, X.; Wang, L.; Feng, P. Synthetic Control of Selenide Supertetrahedral Clusters and Three-Dimensional Co-Assembly by Charge-Complementary Metal Cations Angew. Chem. Int. Ed. 2009, 48, 7204-7207.(hot paper)

• Wu, T.; Zhang, J.; Zhou,C.; Wang, L.; Bu, X.; Feng, P. Zeolite RHO-Type Net with the Lightest Elements, J. Am. Chem. Soc. 2009, 131, 6111-6113.

• Zhang, J.; Wu,T.; Chen, S.; Feng, P.; Bu, X. Versatile Structure-directing Roles of Deep Eutectic Solvents and Their Implication in Generation of Porosity and Open Metal Sites for Gas Storage, Angew. Chem. Int. Ed. 2009, 48, 3486-3490.

• Zhang, J.; Wu,T.; Zhou,C.; Chen, S.; Feng, P.; Bu, X. Zeolitic Boron Imidazolate Frameworks, Angew. Chem. Int. Ed. 2009, 48, 2542-2545. (Hot paper)

• Zhang, Z.; Chen, Q.; Feng, P. Selective Removal of DNA Labelled Nanoparticles from Planar Substrate by DNA Displacement Reaction. Angew. Chem. Int. Ed. 2009, 48, 118-122.

• Zhang, Z; Zhang, J.; Wu, T.; Bu, X.; Feng, P. Three-Dimensional Open Framework Built from Cu-S Icosahedral Clusters and Its Photocatalytic Property. J. Am. Chem. Soc. 2008, 130, 15238-15239.

• Liu, R.; Zhao, X.; Wu, T.; Feng, P. Tunable redox-responsive hybrid nanogated ensembles. J. Am. Chem. Soc. 2008, 130, 14418-14419.

• Zhang, J; Chen, S.; Wu, T.; Feng, P.; Bu, X. Homochiral Crystallization of Microporous Framework Materials from Achiral Precursors by Chiral Catalysis. J. Am. Chem. Soc. 2008, 130, 12882-12883.

• Zhang, Q.; Liu, Y.; Bu, X.; Wu, T.; Feng, P. A Rare (3,4)-Connected Chalcogenide Superlattice and Its Photoelectronic Effect. Angew. Chem. Int. Ed. 2008, 47, 113-116.

• Zhang, J.; Liu, R.; Feng, P.; Bu, X. Organic Cation and Chiral-Anion Templated 3-D Homochiral Open-Framework Materials with Unusual Square Planar M4(OH) Units. Angew. Chem. Int. Ed. 2007, 46, 8388-8391.

• Zhang, Q.; Bu, X.; Zhang, J.; Wu, T.; Feng, P. Chiral Semiconductor Frameworks from Cadmium Sulfide Clusters. J. Am. Chem. Soc. 2007, 129, 8412-8413.

• Zheng, Nanfeng; Lu,Haiwei; Bu,Xianhui; Feng,Pingyun. Metal-Chelate Dye-Controlled Organization of Cd32S14(SPh)404- Nanoclusters into Three-Dimensional Molecular and Covalent Open Architecture.J. Am. Chem. Soc. 2006, 128, 4528-4529.

• Zheng, Nanfeng; Bu, Xianhui; Lu, Haiwei; Chen, Lan; Feng*, Pingyun. One-Dimensional Assembly of Chalcogenide Nanoclusters with Bifunctional Covalent Linkers.J. Am. Chem. Soc. 2005, 127, 14990-14991.

• Zheng,Nanfeng; Bu,Xianhui; Lu, Haiwei; Zhang, Qichun; Feng*, Pingyun "Crystalline Superlattices from Single-Sized Quantum Dots" J. Am. Chem. Soc. 2005, 127, 11963-11965.

• Zheng,Nanfeng; Bu,Xianhui; Vu, Hiep; Feng*,Pingyun Open-Framework Chalcogenides as Visible-Light Photocatalyst for Hydrogen Generation from Water" Angew. Chem. Int. Ed.2005,44, 5699-5303.,

• Zheng,Nanfeng; Bu,Xianhui; Feng*,Pingyun "Na5(In4S)(InS4)3◊6H2O, a Zeolite-like Structure with Uusual SIn4 Tetrahedra." J. Am. Chem. Soc. 2005, 127, 5286-5287.

• Feng*, Pingyun; Bu, Xianhui; Zheng, Nanfeng "The Interface Chemistry between Chalcogenide Clusters and Open Framework Chalcogenides" Acc. Chem. Res. 2005, 38, 293-303.

• Zheng, Nanfeng; Bu, Xianhui; Feng*, Pingyun "Penta-Supertetrahedral Clusters as Building Blocks for Three-Dimensional Sulfide Superlattice" Angew. Chem. Int. Ed. 2004, 43, 4753-4755.

• Bu, Xianhui; Zheng, Nanfeng; Wang, Xiqing; Wang, Bing; Feng*, Pingyun "Three-Dimensional Frameworks of Gallium Selenide Supertetrahedral Clusters" Angew. Chem. Int. Ed. 2004, 43, 1502-1505.

• Zheng, Nanfeng; Bu, Xianhui; Feng*, Pingyun "Synthetic design of crystalline inorganic chalcogenides exhibiting fast-ion conductivity" Nature 2003, 426, 428-432.

• Bu, Xianhui; Zheng, Nanfeng; Li, Yuqi; Feng*, Pingyun "Templated Assembly of Sulfide Nanoclusters into Cubic-C3N4 Type Framework." J. Am. Chem. Soc. 2003, 125, 6024-6025.

• Zheng, Nanfeng; Bu,Xianhui; Feng*, Pingyun "Nonaqueous Synthesis and Selective Crystallization of Gallium Sulfide Clusters into Three-Dimensional Photoluminescent Superlattices" J. Am. Chem. Soc. 2003, 125, 1138-1139.

• Zheng, Nanfeng; Bu,Xianhui; Wang, Bing; Feng*, Pingyun "Microporous and Photoluminescent Chalcogenide Zeolite Analogs" Science 2002, 298, 2366-2369.

• Bu,Xianhui; Zheng, Nanfeng; Li, Yuqi, Feng*, Pingyun "Pushing Up the Size Limit of Chalcogenide Supertetrahedral Clusters: Two- and Three-Dimensional Photoluminescent Open Frameworks from T5 (Cu5In30S54)13- Nanoclusters." J. Am. Chem. Soc. 2002, 124, 12646-12647.

• Wang, Cheng; Bu,Xianhui; Zheng, Nanfeng; Feng*, Pingyun "Nanocluster with One Missing Core Atom: A Three-Dimensional Hybrid Superlattice Built from Dual-Sized Supertetrahedral Clusters." J. Am. Chem. Soc. 2002, 124, 10268-10269.

• Zheng, Nanfeng; Bu,Xianhui; Feng*, Pingyun "Self-Assembly of Novel Dye Molecules and [Cd8(SPh)12]4+ Cubic Clusters into Three-Dimensional Photoluminescent Superlattice." J. Am. Chem. Soc. 2002, 124, 9688-9689.

• Wang, Cheng; Bu, Xianhui; Zheng, Nanfeng; Feng*, Pingyun "A Three-dimensional Open Framework Indium Telluride and Its Selenide and Sulfide Analogues." Angew. Chem. 2002, 41,1959-1961.(Hot Paper)

• Wang,C.; Li,Y.; Bu,X.; Zheng, N. Zivkovic, O.; Yang,C.; Feng*, P. "Three-dimensional Superlattices Built from (M4In16S33)10- (M = Mn, Co, Zn, Cd) Supertetrahedral Clusters." J. Am. Chem. Soc. 2001, 123, 11506-11507.

• Feng*, Pingyun; Zhang, Tianzhi.; Bu, Xianhui "Arsenate Zeolite Analogs with 11 Topological Types." J. Am. Chem. Soc. 2001, 123, 8608-8609.

• Feng, Pingyun; Bu, Xianhui; Stucky, Galen D.; Pine, David J. "Monolithic mesoporous silica templated by microemulsion liquid crystals." J. Am. Chem. Soc. 2000, 122, 994-995.

• Bu, Xianhui; Feng, Pingyun; Gier, Thurman E.; Zhao, Dongyuan; Stucky, Galen D. "Hydrothermal Synthesis and Structural Characterization of Zeolite-like Structures Based on Gallium and Aluminum Germanates." J. Am. Chem. Soc. 1998, 120, 13389-13397.

• Bu, Xianhui; Feng, Pingyun; Stucky, Galen D. "Novel Germanate Zeolite Structures with 3-Rings." J. Am. Chem. Soc. 1998, 120, 11204-11205.

• Bu, Xianhui; Feng, Pingyun; Stucky, Galen D. "Large-cage zeolite structures with multidimensional 12-ring channels." Science 1997, 278, 2080-2085.

• Feng, Pingyun; Bu, Xianhui; Stucky, Galen D. "Hydrothermal syntheses and structural characterization of zeolite analog compounds based on cobalt phosphate." Nature 1997, 388, 735-741.

• Feng, Pingyun; Bu, Xianhui; Tolbert, Sarah H.; Stucky, Galen D. "Syntheses and Characterizations of Chiral Tetrahedral Cobalt Phosphates with Zeolite ABW and Related Frameworks." J. Am. Chem. Soc. 1997, 119, 2497-2504.

• Feng, Pingyun; Bu, Xianhui; Stucky, Galen D. "Designed assemblies in open framework materials synthesis: an interrupted sodalite and an expanded sodalite." Angew. Chem., Int. Ed. Engl. 1995, 34, 1745-7.