A5079084961- Electrocatalysts for Energy Conversion
- Fuel Cells and Related Materials
- Catalytic Processes in Materials Science
- Advanced battery technologies research
- Graphene research and applications
- Advanced Memory and Neural Computing
- Semiconductor materials and devices
- Electronic and Structural Properties of Oxides
- Advancements in Battery Materials
- Advanced Photocatalysis Techniques
- Supercapacitor Materials and Fabrication
- Environmental remediation with nanomaterials
- Laser-Ablation Synthesis of Nanoparticles
- Oxidative Organic Chemistry Reactions
- Membrane Separation and Gas Transport
- Membrane-based Ion Separation Techniques
- Transition Metal Oxide Nanomaterials
- Surface and Thin Film Phenomena
- Membrane Separation Technologies
- Molecular Junctions and Nanostructures
- Extraction and Separation Processes
- Radioactive element chemistry and processing
- Catalysis and Oxidation Reactions
- 2D Materials and Applications
- Nanomaterials for catalytic reactions
Massachusetts Institute of Technology
2020-2024
Georgia Institute of Technology
2015-2020
AID Atlanta
2018-2020
One of the key challenges that hinders broad commercialization proton exchange membrane fuel cells is high cost and inadequate performance catalysts for oxygen reduction reaction (ORR). Here we report a composite ORR catalyst consisting ordered intermetallic Pt-alloy nanoparticles attached to an N-doped carbon substrate with atomically dispersed Fe–N–C sites, demonstrating substantially enhanced catalytic activity durability, achieving half-wave potential 0.923 V (vs. RHE) negligible loss...
Abstract Mixed transition‐metals (TM) based catalysts have shown huge promise for water splitting. Conventional synthesis of nanomaterials is strongly constrained by room‐temperature equilibria and Ostwald ripening. Ultra‐fast temperature cycling enables the metastable metallic phases high entropy alloy nanoparticles, which later transform to oxide/hydroxide nanoparticles upon use in aqueous electrolytes. Herein, an situ non‐noble metal oxide (HEO) on carbon fibers rapid Joule heating...
The ability to synthesize compositionally complex nanostructures rapidly is a key high-throughput functional materials discovery. In addition being time-consuming, majority of conventional synthesis processes closely follow thermodynamics equilibria, which limit the discovery new classes metastable phases such as high entropy oxides (HEO). Herein, photonic flash HEO nanoparticles at timescales milliseconds demonstrated. By leveraging abrupt heating and cooling cycles induced by...
We present a scalable one-pot strategy for the green fabrication of nitrogen-enriched graphitic-like hierarchical porous sub-100 nm carbon (denoted as N-HMPC) nanocapsules with controllable N-content ORR experimentally and theoretically.
After electrochemical de-alloying, PtCu/C catalyst with a rich Pt shell demonstrated an enhanced ORR activity and superior durability.
Abstract Although numerous efforts are made to synthesize active electrocatalysts for green hydrogen production; catalyst stability, and facile synthesis scale up the production still challenging. Herein, of novel non‐PGM catalysts oxygen reduction reaction (OER) in an alkaline aqueous medium is reported, which based on a trimetallic metal–organic framework (MOF) precursors. Fine‐tuning composition metal centers (Ni, Co, Fe) shows great effect OER activity after MOF undergoes dynamic...
In this study, we explore the dimensional aspect of structure-driven surface properties metal monolayers grown on a graphene/Au template. Here, limited redox replacement (SLRR) is used to provide precise layer-by-layer growth Pt graphene. We find that after few iterations SLRR, fully wetted 4-5 monolayer films can be Incorporating graphene at Pt-Au interface modifies mechanism, charge transfers, equilibrium interatomic distances, and associated strain synthesized monolayers. single layer...
Revolutionary catalyst protection by single layer graphene capping, tremendous lifetime longevity and activity enhancement towards oxygen reduction reaction.
We report on the first fabrication of vertically oriented niobium–zirconium oxynitride nanotube arrays and their use as an attractive robust material for visible-light-driven water oxidation. These with average diameter ∼120 nm very short length ∼90 were synthesized via one-step anodization Nb–Zr alloy sheet in NH4F-containing electrolytes. Ammonolysis nanotubes resulted narrowing bandgap energy from 3.23 to ∼2.67 eV. The showed approximately enhancement about 1900% over that reported thin...
Abstract The nature of the atomic configuration and bonding within epitaxial Pt‐graphene films is investigated. Graphene‐templated monolayer/few‐multilayers Pt, synthesized as contiguous 2D by room temperature electrochemical methods, shown to exhibit a stable {100} structure in 1–2 layer range. fundamental question being investigated whether surface Pt atoms rendered these architectures are those their bulk counterparts. Unsurprisingly, single on graphene (Pt_1ML/GR) shows much larger...
Economical production of highly active and robust Pt catalysts on a large scale is vital to the broad commercialization polymer electrolyte membrane fuel cells. Here, we report low-cost, one-pot process for large-scale synthesis single-crystal multipods with abundant high-index facets, in an aqueous solution without any template or surfactant. A composite consisting (40 wt %) carbon displays specific activity 0.242 mA/cm2 mass 0.109 A/mg at 0.9 V (versus reversible hydrogen electrode) oxygen...
The concept of a core–shell metallic structures, with few atomic layers the "shell" metal delineated from "core" sharpness opens door to multitude surface-driven materials properties that can be tuned. However, in practice, such architectures are difficult retain due entropic cost segregated near-surface architecture, and core surface atoms inevitably mix through interdiffusion over time. We present here systematic study Pt on Au architecture role an interrupting single layer graphene...
Platinum atomic layers grown on graphene were investigated by resolution transmission electron microscopy (TEM). These TEM images reveal the epitaxial relationship between atomically thin platinum and graphene, with two optimal epitaxies observed. The energetics of these influences grain structure film, facilitating growth via in-plane rotation assimilation neighbor grains, rather than coarsening from movement boundaries. This process was enabled due to availability several possible...
Understanding the nature of interfacial defects materials is a critical undertaking for design high-performance hybrid electrodes photocatalysis applications.
Abstract Over the past decades, design of active catalysts has been subject intense research efforts. However, there significantly less deliberate emphasis on rationally designing a catalyst system with prolonged stability. A major obstacle comes from ambiguity behind how degrades. Several degradation mechanisms are proposed in literature, but lack systematic studies, causal relations between and those remain ambiguous. Here, study comprising small particles single atoms Pt sandwiched...