Publications de Kumar Varoon Agrawal

Print-light-synthesis of electrocatalytically active gas diffusion electrodes for fuel cell applications

Hubert Girault, Luc Sébastien Bondaz, Kumar Varoon Agrawal

The present work reports a simple approach to manufacture electrocatalytically active gas diffusion electrodes (GDEs) in two steps: (i) inkjet printing and (ii) flash light irradiation from a xenon flash lamp, a process called Print-light-synthesis (PLS). ...

Royal Society of Chemistry2025

Non-van-der-Waals Oriented Two-Dimensional UiO-66 Films by Rapid Aqueous Synthesis at Room Temperature

Wendy Lee Queen, Kumar Varoon Agrawal, Heng-Yu Chi, Qi Liu, Kuang-Jung Hsu, Kangning Zhao, Shuqing Song, Ranadip Goswami

The synthesis of MOFs in a two-dimensional (2D) film morphology is attractive for several applications including molecular and ionic separation. However, 2D MOFs have only been reported from structures that crystallize in lamellar morphology, where layers ...

2025

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

Anisotropic node distortions in amorphous MOFs: Low-valent Zr sites as catalytic hotspots

Emad Oveisi, Berend Smit, Wendy Lee Queen, Kumar Varoon Agrawal, Vikram Vinayak Karve, Andres Adolfo Ortega Guerrero, Till Marian Schertenleib, Jian Hao, Beatriz Bueno Mouriño, Timo Markus Oskar Felder

We introduce a new approach to defect engineering in Zr-based metal-organic frameworks (Zr-MOFs), aiming to reduce Zr site valency while preserving high node connectivity. Using a rapid heat treatment (RHT) in humid air, oxygen vacancies (O-vacancies) were ...

Elsevier BV2025

Advancing membrane science via two-dimensional materials

Kumar Varoon Agrawal

2025

Angstrom‐Scale Triangular Pore in Single‐Layer Hexagonal Boron Nitride Membrane for Molecular Sieving

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi

Single‐layer crystalline films are ideal separation membrane materials because their atomic thickness could yield the highest possible molecular flux once nanopores are generated. However, the development of single‐layer membranes with well‐defined pore st ...

Wiley2025

Stereochemical tuning, post-synthesis crosslinking and quaternizing to tune the membrane performance of ultra-stable polyamine nanofiltration membranes

Kumar Varoon Agrawal, Cédric Karel J Van Goethem

Solvent resistant and pH-stable nanofiltration membranes play a crucial role in solvent or water reuse across various industries, including pharma, chemical, dairy and mining, where stringent pH conditions and chemical stability are imperative. Previous re ...

2025

Optimization of crosslinking in Poly(vinylidene fluoride) membranes for solvent-resistant nanofiltration: a comparative study between crosslinking agents

Kumar Varoon Agrawal, Cédric Karel J Van Goethem

This study presents an optimized and scalable crosslinking approach for poly(vinylidene fluoride) (PVDF) membranes in solvent-resistant nanofiltration (SRNF), emphasizing cost efficiency, safety, and environmental sustainability. The effect of four swellin ...

2025

A molecularly engineered large-area nanoporous atomically thin graphene membrane for ion separation

Kumar Varoon Agrawal

Atomically thin graphene membranes with sub-1-nm pores show promise for ion/molecular separation, osmotic energy generation, and energy storage. Narrowing the pore size distribution and controlling the surface charge are essential to achieve these applicat ...

Springer Science and Business Media LLC2025

Nanolithography of the nanocorral structure of chemisorbed oxygen atoms on the graphitic lattice

Kumar Varoon Agrawal, Shaoxian Li

Controlled atomic patterning is an attractive tool to fine tune properties of graphitic lattice. Several O-functionalized derivatives of graphitic lattice have been widely studied, e.g., graphene oxide, reduced graphene oxide, and functionalized carbon nan ...

Pergamon-Elsevier Science Ltd2024

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

Influence of micro-patterned support properties and interfacial polymerization conditions on performance of patterned thin-film composite membranes

Kumar Varoon Agrawal, Cédric Karel J Van Goethem

Patterned membranes prepared via spray-modified non -solvent induced phase separation (s-NIPS) have successfully shown enhanced fluxes and better fouling control, thanks to the increased surface area and high fluid shear at the membrane/feed interface. The ...

Elsevier2024

Dynamic Behavior of Spatially Confined Sn Clusters and Its Application in Highly Efficient Sodium Storage with High Initial Coulombic Efficiency

Xu Xu, Kumar Varoon Agrawal, Lei Zhang, Kangning Zhao

Advanced battery electrodes require a cautious design of microscale particles with built-in nanoscale features to exploit the advantages of both micro- and nano-particles relative to their performance attributes. Herein, the dynamic behavior of nanosized S ...

Wiley-V C H Verlag Gmbh2024

Direct synthesis of nanocrystalline single-layer porous graphene for hydrogen sieving

Luc Sébastien Bondaz, Kumar Varoon Agrawal, Jian Hao

Porous single -layer graphene is promising as the selective layer for membrane-based gas separation thanks to the atomic thickness of the pore which can yield high permselective flux. Direct synthesis of porous graphene by chemical vapor deposition (CVD) i ...

Pergamon-Elsevier Science Ltd2024

Advancing Molecular Sieving via Å-Scale Pore Tuning in Bottom-Up Graphene Synthesis

Mounir Driss Mensi, Kumar Varoon Agrawal, Heng-Yu Chi, Kangning Zhao, Cédric Karel J Van Goethem

Porous graphene films are attractive as a gas separation membrane given that the selective layer can be just one atom thick, allowing high-flux separation. A favorable aspect of porous graphene is that the pore size, essentially gaps created by lattice def ...

Amer Chemical Soc2024

Method of preparation of ultrathin metal-organic frameworks & uses thereof

Kumar Varoon Agrawal, Qi Liu

The invention relates to methods for the preparation of ultrathin metal-organic frameworks (MOFs), in particular Zeolitic imidazolate frameworks (ZIFs) and uses thereof and resulting products thereof, in particular useful for the preparation of gas separat ...

2024

Electrochemical-repaired porous graphene membranes for precise ion-ion separation

Kumar Varoon Agrawal, Heng-Yu Chi, Kuang-Jung Hsu, Kangning Zhao, Shuqing Song, Zongyao Zhou

The preparation of atom-thick porous lattice hosting & Aring;-scale pores is attractive to achieve a large ion-ion selectivity in combination with a large ion flux. Graphene film is an ideal selective layer for this if high-precision pores can be incorpora ...

Nature Portfolio2024

High-performance H2/CO2 separation from 4-nm-thick oriented Zn2(benzimidazole)4 films

Kumar Varoon Agrawal, Heng-Yu Chi, Qi Liu, Shuqing Song, Zongyao Zhou, Ranadip Goswami

High-performance membrane-based H2/CO2 separation offers a promising way to reduce the energy costs of precombustion capture. Current membranes, often made from two-dimensional laminates like metal-organic frameworks, have limitations due to complex fabric ...

2024

Tuning Pore Size in Graphene in the Angstrom Regime for Highly Selective Ion-Ion Separation

Kumar Varoon Agrawal, Luis Francisco Villalobos Vazquez de la Parra, Heng-Yu Chi, Wan-Chi Lee, Shaoxian Li, Kuang-Jung Hsu, Kangning Zhao, Yuyang Zhang

Zero-dimensional pores spanning only a few angstroms in size in two-dimensional materials such as graphene are some of the most promising systems for designing ion-ion selective membranes. However, the key challenge in the field is that so far a crack-free ...

Amer Chemical Soc2024

Method of preparation of ultrathin metal-organic frameworks & uses thereof

Kumar Varoon Agrawal, Qi Liu

The invention relates to methods for the preparation of ultrathin metal-organic frameworks (MOFs), in particular Zeolitic imidazolate frameworks (ZIFs) and uses thereof and resulting products thereof, in particular useful for the preparation of gas separat ...

2024