Hua Bai

Bio: Hua Bai is an academic researcher from Xiamen University. The author has contributed to research in topics: Graphene & Polyaniline. The author has an hindex of 50, co-authored 117 publications receiving 16465 citations. Previous affiliations of Hua Bai include Tsinghua University & Southeast University.

Flexible Graphene Films via the Filtration of Water-Soluble Noncovalent Functionalized Graphene Sheets

Abstract: Flexible graphene films were prepared by the filtration of water-soluble noncovalently functionalized graphene sheets with pyrenebutyrate. The work presented here will not only open a new way for preparing water-soluble graphene dispersions but also provide a general route for fabricating conducting films based on graphene.

Gas Sensors Based on Conducting Polymers

Abstract: The gas sensors fabricated by using conducting polymers such as polyaniline (PAni), polypyrrole (PPy) and poly (3,4-ethylenedioxythiophene) (PEDOT) as the active layers have been reviewed. This review discusses the sensing mechanism and configurations of the sensors. The factors that affect the performances of the gas sensors are also addressed. The disadvantages of the sensors and a brief prospect in this research field are discussed at the end of the review.

Functional Composite Materials Based on Chemically Converted Graphene

Abstract: Graphene, a one-atom layer of graphite, possesses a unique two-dimensional structure and excellent mechanical, thermal, and electrical properties. Thus, it has been regarded as an important component for making various functional composite materials. Graphene can be prepared through physical, chemical and electrochemical approaches. Among them, chemical methods were tested to be effective for producing chemically converted graphene (CCG) from various precursors (such as graphite, carbon nanotubes, and polymers) in large scale and at low costs. Therefore, CCG is more suitable for synthesizing high-performance graphene based composites. In this progress report, we review the recent advancements in the studies of the composites of CCG and small molecules, polymers, inorganic nanoparticles or other carbon nanomaterials. The methodology for preparing CCG and its composites has been summarized. The applications of CCG-based functional composite materials are also discussed.

A water-soluble cationic oligopyrene derivative : Spectroscopic studies and sensing applications

Abstract: A water-soluble cationic conjugated oligomer, oligo(2-(4-(1-pyrenyl)butanoyloxy)ethyltrimethylammonium bromide) (OPBEAB) was synthesized by the combination of chemical and electrochemical synthesis techniques. The oligomer has an average repeat unit of 4 and a high quantum yield ( Ф ) of 0.7 in an aqueous solution containing 5.91 × 10 −3 mol L −1 sodium dodecyl sulfate (SDS). In this medium, surfactant molecules formed shielding layers along the OPBEAB chains and prevented aggregation of the oligomer and also improved its fluorescence stability. The fluorescence quenching of cationic oligomer (OPBEAB) depends strongly on the mixing sequence of the probe molecule (OPBEAB), analyte (TNT), and anionic surfactant (SDS). A molecule probe based on OPBEAB can rapidly detect ultra-trace TNT in both pure aqueous solution and environmental ground water with high sensitivity. The Stern–Volmer constant ( K SV ) of the probe in aqueous solution was measured to be as high as 5.30 × 10 5 mol −1 L and the limit of detection was about 7.0 × 10 −8 mol L −1 (70 ppb) under optimized conditions.

Three-Dimensional Self-Assembly of Graphene Oxide and DNA into Multifunctional Hydrogels

Abstract: Graphene and its functionalized derivatives are unique and versatile building blocks for self-assembly to fabricate graphene-based functional materials with hierarchical microstructures. Here we report a strategy for three-dimensional self-assembly of graphene oxide sheets and DNA to form multifunctional hydrogels. The hydrogels possess high mechanical strength, environmental stability, and dye-loading capacity, and a exhibit self-healing property. This study provides a new insight for the assembly of functionalized graphene with other building blocks, especially biomolecules, which will help rational design and preparation of hierarchical graphene-based materials.

The chemistry of graphene oxide

Abstract: The chemistry of graphene oxide is discussed in this critical review Particular emphasis is directed toward the synthesis of graphene oxide, as well as its structure Graphene oxide as a substrate for a variety of chemical transformations, including its reduction to graphene-like materials, is also discussed This review will be of value to synthetic chemists interested in this emerging field of materials science, as well as those investigating applications of graphene who would find a more thorough treatment of the chemistry of graphene oxide useful in understanding the scope and limitations of current approaches which utilize this material (91 references)

Improved Synthesis of Graphene Oxide

Abstract: An improved method for the preparation of graphene oxide (GO) is described. Currently, Hummers’ method (KMnO4, NaNO3, H2SO4) is the most common method used for preparing graphene oxide. We have found that excluding the NaNO3, increasing the amount of KMnO4, and performing the reaction in a 9:1 mixture of H2SO4/H3PO4 improves the efficiency of the oxidation process. This improved method provides a greater amount of hydrophilic oxidized graphene material as compared to Hummers’ method or Hummers’ method with additional KMnO4. Moreover, even though the GO produced by our method is more oxidized than that prepared by Hummers’ method, when both are reduced in the same chamber with hydrazine, chemically converted graphene (CCG) produced from this new method is equivalent in its electrical conductivity. In contrast to Hummers’ method, the new method does not generate toxic gas and the temperature is easily controlled. This improved synthesis of GO may be important for large-scale production of GO as well as the ...

Chemical methods for the production of graphenes.

Abstract: Interest in graphene centres on its excellent mechanical, electrical, thermal and optical properties, its very high specific surface area, and our ability to influence these properties through chemical functionalization. There are a number of methods for generating graphene and chemically modified graphene from graphite and derivatives of graphite, each with different advantages and disadvantages. Here we review the use of colloidal suspensions to produce new materials composed of graphene and chemically modified graphene. This approach is both versatile and scalable, and is adaptable to a wide variety of applications.

Graphitic Carbon Nitride (g-C3N4)-Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?

Abstract: As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

Abstract: Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...