Publications by Shiqi Huang | EPFL Graph Search

Modulation of Graphene Oxidation Using Substrate-Induced Electron-Hole Puddles for Advancing Molecular Separation

Kumar Varoon Agrawal, Shiqi Huang, Heng-Yu Chi, Kuang-Jung Hsu, Ranadip Goswami

Tuning the reactivity of graphene enables molecular-level engineering of the lattice, achieving desired chemical and structural properties through functionalization, doping, and etching. Atom-thin graphene film hosting Å-scale pores, with capability to dif ...

2025

Graphene membranes with pyridinic nitrogen at pore edges for high-performance CO2 capture

Andreas Züttel, Kumar Varoon Agrawal, Shiqi Huang, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi, Shaoxian Li, Kuang-Jung Hsu, Marina Micari, Xuekui Duan, Liping Zhong, Shuqing Song

Membranes based on a porous two-dimensional selective layer offer the potential to achieve exceptional performance to improve energy efficiency and reduce the cost for carbon capture. So far, separation from two-dimensional pores has exploited differences ...

Nature Portfolio2024

Unraveling the Oxidation of a Graphitic Lattice: Structure Determination of Oxygen Clusters

Nicola Marzari, Kumar Varoon Agrawal, Shiqi Huang, Shaoxian Li

Unraveling the oxidation of graphitic lattice is of great interest for atomic-scale lattice manipulation. Herein, we build epoxy cluster, atom by atom, using Van der Waals' density-functional theory aided by Clar's aromatic it-sextet rule. We predict the f ...

Amer Physical Soc2023

Mechanistic Insights on Functionalization of Graphene with Ozone

Nicola Marzari, Luc Sébastien Bondaz, Kumar Varoon Agrawal, Shiqi Huang, Shaoxian Li, Kuang-Jung Hsu, Nicéphore Arthur François Bonnet

The exposure of graphene to O-3 results in functionalization of its lattice with epoxy, even at room temperature. This reaction is of fundamental interest for precise lattice patterning, however, is not well understood. Herein, using van der Waals density ...

Amer Chemical Soc2023

In Situ Nucleation-Decoupled and Site-Specific Incorporation of angstrom-Scale Pores in Graphene Via Epoxidation

Nicola Marzari, Luc Sébastien Bondaz, Kumar Varoon Agrawal, Shiqi Huang, Mohammad Tohidivahdat, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi, Shaoxian Li, Kuang-Jung Hsu, Victor Carle Adrien Boureau

Generating pores in graphene by decoupled nucleation and expansion is desired to achieve a fine control over the porosity, and is desired to advance several applications. Herein, epoxidation is introduced, which is the formation of nanosized epoxy clusters ...

Wiley-V C H Verlag Gmbh2022

Enhanced Water Evaporation from A-Scale Graphene Nanopores

Mounir Driss Mensi, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Wan-Chi Lee, Kuang-Jung Hsu

Enhancing the kinetics of liquid-vapor transition from nanoscale confinements is an attractive strategy for developing evaporation and separation applications. The ultimate limit of confinement for evaporation is an atom thick interface hosting angstrom-sc ...

AMER CHEMICAL SOC2022

Crack-Free Monolayer Graphene Interlayer for Improving Perovskite Crystallinity and Energy Level Alignment in Efficient Inverted Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Kumar Varoon Agrawal, Shiqi Huang, Hiroyuki Kanda, Yen-Cheng Liu

Inverted planar perovskite solar cells (PSCs) have intrigued great promise in negative hysteresis, simple fabrication process, and flexible substrate implementation, in which the shared hole transport materiel is NiOx. However, the low-temperature solution ...

WILEY-V C H VERLAG GMBH2022

Structure Evolution of Graphitic Surface upon Oxidation: Insights by Scanning Tunneling Microscopy

Mounir Driss Mensi, Nicola Marzari, Kumar Varoon Agrawal, Shiqi Huang, Mohammad Tohidivahdat, Shaoxian Li, Kuang-Jung Hsu

Oxidation of graphitic materials has been studied for more than a century to synthesize materials such as graphene oxide, nanoporous graphene, and to cut or unzip carbon nanotubes. However, the understanding of the early stages of oxidation is limited to t ...

AMER CHEMICAL SOC2022

Systematic design of millisecond gasification reactor for the incorporation of gas-sieving nanopores in single-layer graphene

Kumar Varoon Agrawal, Shiqi Huang, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Kuang-Jung Hsu

Etching an ensemble of vacancy defects (nanopores) in single-layer graphene (SLG) to obtain a high density of nanopores with an effective size that enables high-performance gas sieving is challenging. This is because nanopore nucleation and expansion are u ...

2021

Multipulsed Millisecond Ozone Gasification for Predictable Tuning of Nucleation and Nucleation-Decoupled Nanopore Expansion in Graphene for Carbon Capture

Mounir Driss Mensi, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi, Wan-Chi Lee, Kuang-Jung Hsu

Predictable and tunable etching of angstrom-scale nanopores in single-layer graphene (SLG) can allow one to realize high-performance gas separation even from similar-sized molecules. We advance toward this goal by developing two etching regimes for SLG whe ...

2021

Bottom-up synthesis of graphene films hosting atom-thick molecular-sieving apertures

Emad Oveisi, Mina Moradi, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Kuang-Jung Hsu, Victor Carle Adrien Boureau, Kangning Zhao, Cédric Karel J Van Goethem

Incorporation of a high density of molecular-sieving nanopores in the graphene lattice by the bottom-up synthesis is highly attractive for high-performance membranes. Herein, we achieve this by a controlled synthesis of nanocrystalline graphene where incom ...

National Academy of Sciences2021

Millisecond lattice gasification for high-density CO2- and O2-sieving nanopores in single-layer graphene

Mounir Driss Mensi, Emad Oveisi, Deepu Joseph Babu, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Shaoxian Li, Marina Micari

Etching single-layer graphene to incorporate a high pore density with sub-angstrom precision in molecular differentiation is critical to realize the promising high-flux separation of similar-sized gas molecules, e.g., CO2 from N2. However, rapid etching ki ...

2021

Etching nanopores in single-layer graphene with a sub-angstrom resolution in molecular sieving

Shiqi Huang

Single-layer graphene (SLG) membranes, hosting molecular-sieving nanopores have been regarded as the ultimate gas separation membranes, attributing to the fact that they are the thinnest possible molecular barrier. However, the expected attractive performa ...

EPFL2021

Centimeter-scale gas-sieving nanoporous single-layer graphene membrane

Luc Sébastien Bondaz, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Wan-Chi Lee

High-permeance, molecular-sieving, nanoporous single-layer graphene (NSLG) membranes are highly promising for gas separation. However, the formation of cracks during the transfer of NSLG to a low-cost porous support is difficult to avoid. These cracks are ...

2020

Polybenzimidazole copolymer derived lacey carbon film for graphene transfer and contamination removal strategies for imaging graphene nanopores

Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Luis Francisco Villalobos Vazquez de la Parra, Wan-Chi Lee

The study of the nanometer-scale vacancy defects (nanopores) in graphene by transmission electron microscopy (TEM) is severely hindered by the presence of polymeric residues originating from the graphene-transfer-step to the TEM grid. The state-of-the-art ...

2020

Hydrogen-sieving single-layer graphene membranes obtained by crystallographic and morphological optimization of catalytic copper foil

Kumar Varoon Agrawal, Shiqi Huang, Shaoxian Li

Gas separation membranes based on single-layer-graphene are highly attractive because the size of graphene nanopores can be tuned to separate gases by the size-sieving mechanism. A prerequisite for this, the synthesis of high-quality polycrystalline single ...

2020

Synergistic CO2-Sieving from Polymer with Intrinsic Microporosity Masking Nanoporous Single-Layer Graphene

Mounir Driss Mensi, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Jing Zhao, Luis Francisco Villalobos Vazquez de la Parra, Wan-Chi Lee

High-flux nanoporous single-layer graphene membranes are highly promising for energy-efficient gas separation. Herein, in the context of carbon capture, a remarkable enhancement in the CO(2)selectivity is demonstrated by uniquely masking nanoporous single- ...

WILEY-V C H VERLAG GMBH2020

Hydrogen sieving from intrinsic defects of benzene-derived single-layer graphene

Mina Moradi, Kumar Varoon Agrawal, Shiqi Huang, Mostapha Dakhchoune, Jing Zhao, Majharul Haque Khan

Single-layer graphene films, crystallized by chemical vapor deposition, host a low density of vacancy defects that are attractive for the size-sieving of molecules. The size and the density of such defects are a function of the growth temperature and the c ...

2019

High-permeance polymer-functionalized single-layer graphene membranes that surpass the postcombustion carbon capture target

Mounir Driss Mensi, Emad Oveisi, Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Jing Zhao, Luis Francisco Villalobos Vazquez de la Parra

Membrane-based postcombustion carbon capture can reduce the capture penalty in comparison to absorbent-based separation. To realize this, high-performance membranes are urgently needed with a CO2 permeance exceeding 1000 gas permeation units or GPU, and a ...

2019

Electrophoretic Nuclei Assembly for Crystallization of High Performance Membranes on Unmodified Supports

Kumar Varoon Agrawal, Shiqi Huang, Guangwei He, Mostapha Dakhchoune, Jing Zhao

Metal-organic frameworks (MOFs) films have recently emerged as highly permselective membranes yielding orders of magnitude higher gas permeance than that from the conventional membranes. However, synthesis of highly-intergrown, ultrathin MOF films on porou ...

2018