Position title: Francis J. DiSalvo Professor of Physical Science
Room 3363A, Department of Chemistry
1101 University Avenue
Madison, WI 53706
- Research Website
- Jin Group
- B.S. 1997, Peking University (China)
- Ph.D. 2002, Cornell University
Research in the Jin group focuses on the rational synthesis, fundamental understanding, and physical properties of nanoscale and solid-state materials to address the challenges in renewable energy, information technology, and biomedicine. We have pioneered dislocation-driven nanomaterial growth and developed the innovative synthesis of nanomaterials including metal silicides, chalcogenides, and halide perovskites. Building on a better understanding of novel physical properties, we advance the exploitation of (nano)materials for electrocatalysis, energy conversion, and storage, optoelectronics, spintronics, and biotechnology. Our energy research aims to overcome the intermittency challenge of renewable energy by using earth-abundant materials. Summarized below are our ongoing research areas:
Nanomaterial Growth Driven by Screw Dislocations and non-Euclidean Geometry
Rationally and precisely controlling the size, dimension, and morphology of nanostructures allows us to tune the electronic structures and quantum states of matter, and discover new physical properties, thus enabling applications in electronics, photonics, spintronics, and renewable energy. We have discovered and developed screw dislocation-driven growth of 1D nanowires and nanotubes, 2D spiral nanoplates, and 3D tree-like nanomaterials. The self-perpetuating steps of a screw dislocation spiral can provide fast crystal growth under low supersaturation conditions to enable the anisotropic crystal growth of diverse nanomaterials. Furthermore, in 2D layered materials such as metal dichalcogenides (MX2), screw dislocations can influence their chirality and layer stackings, and thus the physical properties. We recently achieved systematic interlayer twisting of MX2 spiral layers due to mismatched geometry between Euclidean crystal lattices and non-Euclidean (curved) surfaces, which can lead to moiré superlattices, nonlinear optical properties, chiral optoelectronics, twistronics and novel quantum phenomena. We aim to create a new dimension in the rational synthesis of nanomaterials and enable the controllable and scalable production of nanomaterials for energy, optoelectronic, and quantum applications.
Metal Halide Perovskite Nanostructures and Heterostructures
Metal halide perovskites have emerged as inexpensive semiconductor materials promising for high-performance solar cells, light-emitting diodes (LEDs), and other optoelectronic applications. Better control over their crystal growth and a better fundamental understanding of the unique photophysics and the factors controlling the carrier transfer of halide perovskites is crucial for guiding the strategies to improve them for applications. We have achieved the growth of single-crystal nanostructures of 3D halide perovskites and large-area nanosheets of 2D Ruddlesden-Popper (RP) layered perovskites and used them to create novel and arbitrary vertical, lateral, and other heterostructures with the high-quality interface and tunable band alignments. In collaboration with Prof. John Wright and other spectroscopists, we use time-resolved and multidimensional spectroscopic methods to study the carrier transfer mechanisms between these perovskite heterostructures. New physical properties can further be achieved by tuning the crystal symmetry through the structural engineering of these hybrid halide perovskites. The excellent properties of these perovskite nanostructures can enable high-performance solar cells, LEDs, lasers, spintronic and quantum applications.
Electrocatalytic Conversion of Energy and Chemicals Using Earth-Abundant Nanomaterials
Highly active, selective, robust, and earth-abundant electrocatalysts are needed to enable efficient and sustainable production of energy and fuels using electrocatalytic and photoelectrochemical (PEC) energy conversion. We discover earth-abundant electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) and improve their catalytic activity to enable efficient electrochemical water splitting. For example, controlling the polymorphs and defects of layered metal chalcogenides significantly enhanced their catalytic activity for HER. We established cobalt phosphosulfide (CoPS) as the most efficient earth-abundant HER catalyst in acidic conditions. The OER catalytic activity and stability of metal oxide/hydroxide nanomaterials can be enhanced through controlling doping, nanostructured composites, and structural defects. We also study electrocatalysts to produce hydrogen peroxide (H2O2) and to upgrade biomass-derived platform molecules (such as glycerol) using increasingly affordable renewable electricity. In collaboration with Prof. JR Schmidt, we combine computations and experiments to develop metal chalcogenides as selective and stable catalysts for two-electron oxygen reduction reactions (2e- ORR) in acidic and neutral conditions and study their catalytic mechanisms and active catalytic species using in situ and operando X-ray spectroscopic techniques. These discoveries can enable decentralized electrochemical production of H2O2 for industrial and environmental applications including the electro-Fenton process.
Solar Flow Batteries: Integrated Solar Energy Conversion and Redox Flow Battery Systems
Due to the intermittent nature of sunlight, practical solar energy utilization systems demand both efficient solar energy conversion and inexpensive large-scale energy storage. We have developed hybrid energy storage devices called solar flow batteries (SFBs) that integrate solar cells with redox flow batteries (RFBs). By matching mature solar cells with various organic redox couples and optimizing the SFB device design, we improved their round-trip solar-to-output electricity efficiency (SOEE) and achieved a record SOEE of 20% with a long lifetime using high-performance tandem perovskite/silicon solar cells. The design principles and the quantitative analysis model for voltage matching reveal the pathways for achieving even better performance and stability yet maintaining a low cost, toward practical SFBs for standalone solar energy conversion and storage systems in remote off-grid locations.
Enable Top-Down Proteomics Using Nanotechnology and Materials Chemistry
Top-down mass spectrometry (MS)-based proteomics based on analysis of intact proteins is the most powerful method to comprehensively characterize proteoforms that arise from genetic variations and post-translational modifications (PTMs), but myriad challenges remain due to the extremely complex proteome and the low solubility of many proteins. In collaboration with Prof. Ying Ge, we are developing novel approaches enabled by nanotechnology and materials chemistry to address these challenges. We design magnetic nanoparticles functionalized with specific affinity ligands to capture and enrich low-abundance proteins from serum, blood, and tissue extracts so that complete molecular details of the whole proteins can be revealed by high-resolution mass spectrometry. For example, cardiac troponin, a gold standard biomarker for heart diseases, could be enriched from blood serum and analyzed to reveal molecular fingerprints of diverse cTnI proteoforms. We have also collaboratively developed MS-compatible photocleavable surfactants for solubilizing proteins.