Yuan Chen

Yuan Chen
The University of Sydney · School of Chemical and Biomolecular Engineering

Doctor of Philosophy

About

266
Publications
49,800
Reads
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17,736
Citations
Citations since 2016
135 Research Items
13385 Citations
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201620172018201920202021202205001,0001,5002,0002,500
201620172018201920202021202205001,0001,5002,0002,500
Introduction
My research focuses on developing synthesis and assembly methodologies for carbon materials and investigating the fundamental mechanisms involved in their economical manufacturing and use in sustainable energy and environmental applications.
Additional affiliations
December 2015 - March 2020
The University of Sydney
Position
  • Professor
April 2010 - December 2015
Nanyang Technological University
Position
  • Professor (Associate)
August 2005 - March 2010
Nanyang Technological University
Position
  • Professor (Assistant)
Education
August 2001 - July 2005
Yale University
Field of study
  • Chemical Engineering
July 1999 - July 2001
Tsinghua University
Field of study
  • Biochemical Engineering
September 1995 - June 1999
Tsinghua University
Field of study
  • Chemical Engineering

Publications

Publications (266)
Article
High‐temperature thermal treatment is a standard step in the synthesis of many materials. In recent years, ultrafast heating methods, such as Joule heating, laser, light, or microwave irradiations, have been used to create novel carbon materials and carbon/metal hybrid structures, demonstrating unique and often superior properties compared to those...
Article
Polymer characteristics influence the chiral selectivity and yield in the enrichment of (7,6) from Signis SG76 in toluene by various fluorene homopolymers and copolymers. Fluorene homopolymers such as poly(9,9-di-n-dodecylfluorene) (PFDD) and copolymers with anthracene such as poly[(9,9-dihexylfluorenyl-2,7-diyl)-co-(9,10-Anthracene)] (PFH-A) resul...
Article
ConspectusWearable electronics are smart devices that can be directly worn on the human body. Consumer-grade wearable devices (such as smart bracelets, watches, and glasses) are becoming increasingly popular. They provide continuous and reliable data analysis and guidance in our daily health monitoring and exercise activities. Meanwhile, profession...
Article
Extracting lithium electrochemically from seawater has the potential to resolve any future lithium shortage. However, electrochemical extraction only functions efficiently in high lithium concentration solutions. Herein, we discovered that lithium extraction is temperature and concentration dependent. Lithium extraction capacity (i.e., the mass of...
Article
Catalytic decomposition of methane (CDM) into hydrogen and solid carbon materials (CH4 → 2H2 + C) is a promising approach to achieve environmentally friendly H2 production. However, large amounts of carbon (i.e., H2 to carbon mass ratio of 1 to 3) is generated as a solid by-product. Herein, we show that graphitic carbon materials generated in CDM o...
Article
Direct catalytic decomposition of methane (CDM) has been studied as a possible emission-free hydrogen production route for over 100 years. However, the high cost of catalyst regeneration limits its practical applications. Here, we demonstrate that the solid by-product from CDM using Fe ore catalysts compromising carbon nano onions encapsulated with...
Article
Full-text available
Fenton processes allow to degrade and mineralize toxic organic contaminants, yet classical Fenton processes require continuously adding hydrogen peroxide and ferrous ions, costly solution pH adjustment, and treatment of secondary iron sludge pollution. Heterogeneous electro-Fenton processes deliver oxidizing radicals with only oxygen and electricit...
Article
Efficient and selective oxygen reduction reaction (ORR) electrocatalysts are critical to realizing decentralized H2O2 production and utilization. Here we demonstrate a facile interfacial engineering strategy using a hydrophobic ionic liquid (IL, i.e., [BMIM][NTF2]) to boost the performance of a nitrogen coordinated single atom cobalt catalyst (i.e....
Article
H2O2 sensing is required in various biological and industrial applications, for which electrochemical sensing is a promising choice among various sensing technologies. Electrodes and electrocatalysts strongly influence the performance of electrochemical H2O2 sensors. Significant efforts have been devoted to electrode nanostructural designs and nano...
Article
Monochiral single-walled carbon nanotubes (SWCNTs) can enable high-performance carbon-based electronic devices and integrated circuits. However, their fabrication often requires complex SWCNT purification and enrichment. Herein, we showed that isoindigo-based polymer derivatives (PDPPIID and PFIID) directly enriched (9,8) nanotubes from as-synthesi...
Article
Graphene and two-dimension covalent organic frameworks (2D COFs) with a redox-active skeleton are promising potential capacitive materials for energy storage applications. However, their tendency to form thick laminates severely limit electron transfer and ion diffusion. Herein, we demonstrate graphene hybrids assembled by mixing 2D COFs and reduce...
Chapter
This chapter reviews the development of fiber-shaped micro-supercapacitors (FMSCs), a promising candidate for powering wearable electronics. First, a brief history of fiber-shaped supercapacitors (FSCs) is introduced. As an essential branch of FSCs, the unique characteristics of FMSCs are described. Next, specific design considerations of FMSCs are...
Article
Covalent organic frameworks (COFs) with redox-active moieties are potential capacitive energy storage materials. However, their performance is limited by their poor electrical conductivity and sluggish ion diffusion in their nanopores. Herein, we report coaxial one-dimensional van der Waals heterostructures (vdWHs) comprised of a carbon nanotube (C...
Article
Full-text available
All-carbon field-effect transistors, which combine carbon nanotubes and graphene hold great promise for many applications such as digital logic devices and single-photon emitters. However, the understanding of the physical properties of carbon nanotube (CNT)/graphene hybrid systems in such devices remained limited. In this combined experimental and...
Article
Atomically dispersed transition metal (M) and nitrogen (N) co-doped carbon (M–N–C) electrocatalysts hold excellent application potentials for several critical reactions required in electrochemical conversion processes and energy storage devices, including oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction, carbon diox...
Article
Iron-nitrogen-carbon single-atom catalysts (Fe-N-C SACs) are promising low-cost catalysts for electrochemical CO2 reduction reaction (CO2RR) to achieve carbon neutrality. However, their relatively low selectivity and activity are related to the strong binding of reaction intermediates (e.g., CO*) on single Fe atoms. Here, combining experimental and...
Article
The effect of electrode material’s surface morphology on capacitive deionization (CDI) has been discussed here. For more effective CDI performance, the hierarchical carbon microspheres (HCMs) with vertically aligned nanosheets are designed to obtain the roughest surface. HCMs are derived from the polyimide precursor which is formed by polymerizing...
Article
Two-dimensional covalent organic frameworks (2D-COFs) have well-defined porosity and stability. Herein, we demonstrate that 2D-COFs can have three roles in nanolaminated graphene membranes for organic solvent nanofiltration (OSN). The optimized hybrid nanolaminate, assembled from 2D-COFs and reduced graphene oxide (rGO), shows a 162% enhancement in...
Article
Bulk graphitic carbon materials with expanded interlayer spacing and abundant defects may serve as efficient anodes with high areal capacities for sodium-ion batteries (SIBs). However, obtaining long-range order in bulk graphitic carbon materials with expanded interlayer spacing is extremely difficult. Herein, an explosive decomposition method is d...
Article
Limited by the cost of electrode materials with a pore structure designed, there is an urgent need to prepare a low-cost carbon material with a strong salt absorption capacity (SAC) for capacitive deionization (CDI) to produce fresh water at an affordable price. The preparation of core-shell porous carbon spheres (CSs) derived from the melamine-for...
Article
Nitrogen-coordinated iron atoms on carbon supports (Fe–N–C) are among the most promising noble-metal-free electrocatalysts for oxygen reduction reaction (ORR). However, their unsatisfactory stability limits their practical application. Herein, we demonstrate a dual-shell Fe–N–C electrocatalyst with excellent catalytic activity and long-term stabili...
Article
Rechargeable zinc-air batteries (R-ZABs) are attractive for many essential energy storage applications – from portable electronics, electric vehicles to incorporation of renewable energy due to their high energy storage density, abundant raw materials, and inherent safety. However, alkaline electrolytes cause critical obstacles in realizing a long...
Article
Thermal-driven membrane processes, including membrane distillation (MD) and pervaporation (PV), are promising for various applications. However, they are currently hindered by low productivity, poor long-term stability, and low energy efficiency. Carbon materials, such as activated carbon, carbon black, graphite, carbon nanotubes, and graphene, off...
Article
Decentralized electrosynthesis of hydrogen peroxide (H2O2) via oxygen reduction reaction (ORR) can enable applications in disinfection control, pulping and textile bleaching, wastewater treatment, and renewable energy storage. Transition metal oxides are usually not efficient catalysts because they are more selective to produce H2O. Here, it is sho...
Article
Ionic liquids enable efficient gating of materials with nanoscale morphology due to the formation of a nanoscale double layer that can also follow strongly vaulted surfaces. On carbon nanotubes, this can lead to the formation of a cylindrical gate layer, allowing an ideal control of the drain current even at small gate voltages. In this work, we ap...
Article
Full-text available
Metal halide perovskite solar cells (PSCs) have emerged as promising next‐generation photovoltaic devices with the maximum output efficiency exceeding 25%. Despite significant advances, there are many challenges to achieve high efficiency, stability, and low‐cost simultaneously. Combating these challenges depends on developing novel materials and m...
Article
Transition metal cobalt (oxy)hydroxides are promising catalyst candidates for the oxygen evolution reaction (OER). Their activity can be significantly enhanced by doping chromium; however, the optimal catalyst elemental composition is unknown, and the exact role of Cr remains elusive. Here, density functional theory (DFT) calculations and comprehen...
Article
Catalysts play a critical role in carbon nanotube (CNT) synthesis. The challenge in precisely controlling CNT structures for various applications creates a long-standing goal to develop new and efficient CNT synthesis catalysts. Although sulfur-containing compounds are often used as promoters in CNT synthesis, metal sulfides have not been directly...
Article
Aqueous sodium-ion batteries (A-SIBs) are a cost-effective and safe battery candidate for stationary energy storage systems. Prussian blue and its analogues (PBAs) have been studied as cathode materials in A-SIBs. However, few studies have used PBAs as anode materials because of their small specific capacity and low cell voltages. Herein, we report...
Article
Lithium (Li) production based on the soda evaporation process is time-consuming and unsustainable. The emerging electrochemical Li extraction is time-efficient but requires high-concentration Li sources and significant electrical energy input. Here, we demonstrate a fast, energy-saving, and environment-friendly Li production process by coupling a t...
Article
Two-dimensional covalent organic frameworks (2D-COFs) may serve as an emerging family of catalysts with well-defined atomic structures. However, the severe stacking of 2D nanosheets and large intrinsic bandgaps significantly impair their catalytic performance. Here, we report coaxial one-dimensional van der Waals heterostructures (1D vdWHs) compris...
Article
Graphene aerogels are a promising candidate as multifunctional compressible materials to translate mechanical deformations into electrical signals for a wide range of applications. However, it remains challenging to achieve various desirable properties simultaneously. Here, we demonstrate hierarchical honeycomb graphene aerogels (GCNTAs) reinforced...
Article
Flexible zinc-air batteries (ZABs) have been scrutinized as a type of promising flexible power source for next-generation electronic devices, but the batteries’ temperature adaptability has been a major hurdle due...
Article
Metal−nitrogen−carbon (M−N−C) single-atom catalysts (SACs) show high catalytic activity for many important chemical reactions. However, an understanding of their intrinsic catalytic activity remains ambiguous because of the lack of well-defined atomic structure control in current M−N−C SACs. Here, we use covalent organic framework SACs with an iden...
Article
Full-text available
Noble metal-based intermetallics are promising electrocatalysts for sustainable energy conversion and consumption processes. High-temperature pyrolysis (>500 °C) methods are used to control their crystalline orderings, critical to their electrocatalytic activity and durability. However, the high temperature would cause severe aggregation, resulting...
Article
Full-text available
Resource recovery from natural reserves is appealing and Li extraction from different brines is in the forefront. Li extraction by membranes is reviewed in the literature much more than electrochemical processes. However, a very recent review thoroughly discussed Li recovery by electrochemically switchable ion exchange (ESIX). This paper reviews Li...
Article
2D materials have shown high potentials for fabricating next‐generation membranes. To date, extensive studies have focused on the applications of 2D material membranes in gas and aqueous media. Recently, compelling opportunities emerge for 2D material membranes in separation applications in organic solvents because of their unique properties, such...
Article
Single-atom catalysts (SACs) have the advantages of both homogeneous and heterogeneous catalysts, which show promising application potentials in many renewable energy-conversion technologies and critical industrial processes. In particular, carbon-supported SACs (CS-SACs) are of great interest because of their maximal atom utilization (~100%), uniq...
Article
Full-text available
Metal–organic frameworks (MOFs) are increasingly being investigated as electrocatalysts for the oxygen evolution reaction (OER). Despite their promising catalytic activity, many fundamental questions concerning their structure−performance relationships—especially those regarding the roles of active species—remain to be answered. Here we show the st...
Article
A chloride ion facilitated desolvation effect in aqueous ZnCl2 solutions increases the energy storage capacity of porous carbon electrodes. By utilizing this effect, a flexible zinc ion hybrid capacitor assembled from a ZnCl2 based hydrogel electrolyte and matching porous carbon materials delivers a battery‐level energy density and excellent cyclin...
Article
Full-text available
Flexible batteries, which maintain their functions potently under various mechanical deformations, attract increasing interests due to the potential applications in emerging portable and wearable electronics. Significant efforts have been devoted to material synthesis and structural designs to realize the mechanical flexibility of various batteries...
Article
Octahedral coordinated trivalent cobalt cations (CoOh3+) in metal oxyhydroxides are highly active catalytic sites for the oxygen evolution reaction (OER), a critical bottleneck for efficient water splitting; however, previous synthetic methods have limited control over these sites. Herein, a scalable electrodeposition method coupled with in situ ox...
Preprint
Full-text available
Two-dimensional covalent organic frameworks (2D-COFs) are an emerging family of catalytical materials with well-defined molecular structures. The stacking of 2D nanosheets and large intrinsic bandgaps significantly impair their performance. Here, we report coaxial one-dimensional van der Waals heterostructures (1D vdWHs) comprised of a carbon nanot...
Article
Zinc (Zn) ion hybrid capacitors (ZIHCs) are promising energy storage devices for emerging flexible electronics, but they still suffer from trade-off in energy density and cycling life. Herein, we prove that such a dilemma can be well-addressed by deploying ZnCl 2 based electrolytes. Combining experimental studies and density functional theory (DFT)...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Biomass-derived nanocarbons (BNCs) have attracted significant research interests due to their promising economic and environmental benefits. Following their extensive uses in physical and chemical research domains, BNCs are now growing in biological applications. However, their practical biological applications are still in infancy, requiring criti...
Article
Selective synthesis of single-walled carbon nanotubes (SWCNTs) with narrow chirality distribution at high production yield is critical to realize their applications in electronics and medicine. However, there is a significant trade-off between chirality selectivity and SWCNT yield. In this study, a series of CoSO4/SiO2 catalysts containing from 1 t...
Article
Hydrogen production from direct water electrolysis has long been pursued as a key that may revolutionize the hydrogen economy. With the rapid availability of electricity generated using renewable energy resources, this long-pursued target is now closer to reality than ever before. To date, most studies regarding electrocatalytic hydrogen evolution...
Article
Full-text available
MXenes are emerging rapidly as a new family of multifunctional nanomaterials with prospective applications rivaling that of graphenes. Herein, a timely account of the design and performance evaluation of MXene‐based membranes is provided. First, the preparation and physicochemical characteristics of MXenes are outlined, with a focus on exfoliation,...
Article
Due to strong van der Waals interactions, graphene nanosheets stack together, resulting in inefficient charge storage, which significantly compromises their performance as electrodes in supercapacitors. Herein, we design a hybrid material by interacting covalent organic frameworks (COFs) into reduced graphene oxide (rGO) films or fibers. The 2D COF...
Article
A viscosity-sensitive fluorescence probe is demonstrated by grafting a rotatable 4-N, N’-dimethylaniline group on (6,5) single-walled carbon nanotubes (SWCNTs). The rotation of the grafted group is constricted by solution viscosity,...
Article
Full-text available
Carbon nanotube field effect transistors fabricated on silicon wafers with thermal oxide often suffer from large gate–voltage hysteresis, induced by charge trapping sites in oxides, surface hydroxyl‐groups, and the presence of water molecules. Surface functionalization and passivation, as well as vacuum annealing and reduced operating temperature h...
Article
Graphene oxide (GO) has been widely explored for the improvement of thin-film composite (TFC) membrane performance. However, the influences of GO flake lateral size on the polyamide (PA) TFC membrane properties and performances have not been investigated. In this study, GO suspensions with an average flake size ranging from 0.01 to 1.06 μm² were pr...
Article
Sluggish oxygen evolution reaction (OER) is a crucial limiting factor in many renewable energy conversion and storage devices. Multi-metal oxides have been explored as efficient electrocatalysts for OER; however, the ideal elemental composition for multi-metal oxides is unknown. We first performed density functional theory calculations, which predi...
Article
Hydrogen peroxide (H2O2) detection is essential in many industrial and biological processes. Current applications of H2O2 electrochemical sensors are often limited by the high cost of precious metal electrocatalysts and sophisticated instrumentation requirements. Here, we demonstrate a highly active non-precious metal cobalt/carbon nanocomposite el...
Article
Single-walled carbon nanotubes as emerging quantum-light sources may fill a technological gap in silicon photonics due to their potential use as near-infrared, electrically-driven, classical or non-classical emitters. Unlike in photoluminescence, where nanotubes are excited with light, electrical excitation of single-tubes is challenging and heavil...
Article
Carbon nanotubes (CNTs) with hydrophobic and atomically smooth inner channels are promising for building ultrahigh‐flux nanofluidic platforms for energy harvesting, health monitoring, and water purification. Conventional wisdom is that nanoconfinement effects determine water transport in CNTs. Here, using full‐atomistic molecular dynamics simulatio...
Article
The separation performances of laminate membranes made of two-dimensional (2D) materials depend heavily on their nanoscale structures. Apart from tuning interlayer spacings of 2D materials, pore sizes of supporting substrates also influence membrane performances significantly. Herein, we intercalated a rigid 2D covalent-organic framework (COF) into...
Article
Developing highly efficient earth‐abundant nickel‐based compounds is an important step to realize hydrogen generation from water. Herein, the electronic modulation of the semiconducting NiS2 by cation doping for advanced water electrolysis is reported. Both theoretical calculations and temperature‐dependent resistivity measurements indicate the sem...
Article
Cost‐effective and high‐performance electrocatalysts for oxygen reduction reactions are needed for many energy storage and conversion devices. Here, we demonstrate that whey powder, a major by‐product in the dairy industry, can be used as a sustainable precursor to produce heteroatom doped carbon electrocatalysts for ORR. Rich N and S compounds in...
Article
Developing efficient bifunctional oxygen electrocatalysts is an essential step to realize flexible metal-air batteries to power emerging flexible electronics. Herein, we use a dual-functional metal template to achieve the on-demand control of dispersed active M-N-C sites, porous structures, and surface wettability in a carbon nanofiber catalyst. Th...