Jae Seong Kim

Bio: Jae Seong Kim is an academic researcher from University of Ulsan. The author has contributed to research in topics: Thin film & Nanocomposite. The author has an hindex of 13, co-authored 16 publications receiving 618 citations.

A catalytic and efficient route for reduction of graphene oxide by hydrogen spillover

Abstract: In this paper, an efficient catalytic route for the reduction of graphene oxide (GO) is described using hydrogen spillovered platinum (Pt) nanoparticles at room temperature. Pt nanoparticles were decorated on GO sheets using a hydrogen reduction of chloroplatinic acid. The Pt nanoparticles served as a catalyst for the process of hydrogen disassociation to atomic hydrogen, which spillovered onto the GO sheets which acted as a strong reducing agent for the reduction of GO. Reduced graphene oxide (RGO) obtained in this manner has a C/O atomic ratio as high as 22, which is one of the highest values ever reported for chemically converted graphenes. The electrical conductivity was greater than 8000 S m−1. Electrochemical studies revealed that the RGO–Pt hybrid exhibits excellent electrocatalytic activity toward the methanol oxidation reaction, with high CO tolerance and long-term stability.

Heterogeneous photocatalytic degradation of organic contaminants over titanium dioxide : A review of fundamentals, progress and problems

Abstract: Even though heterogeneous photocatalysis appeared in many forms, photodegradation of organic pollutants has recently been the most widely investigated. By far, titania has played a much larger role in this scenario compared to other semiconductor photocatalysts due to its cost effectiveness, inert nature and photostability. Extensive literature analysis has shown many possibilities of improving the efficiency of photodecomposition over titania by combining the photoprocess with either physical or chemical operations. The resulting combined processes revealed a flexible line of action for wastewater treatment technologies. The choice of treatment method usually depends upon the composition of the wastewater. However, a lot more is needed from engineering design and modelling for successful application of the laboratory scale techniques to large-scale operation. The present review paper seeks to offer an overview of the dramatic trend in the use of the TiO 2 photocatalyst for remediation and decontamination of wastewater, report the recent work done, important achievements and problems.

Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications

Abstract: Graphene, a two-dimensional, single-layer sheet of sp(2) hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene-related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene-based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene-based materials are discussed.

Graphene oxide-based efficient and scalable solar desalination under one sun with a confined 2D water path

Abstract: Because it is able to produce desalinated water directly using solar energy with minimum carbon footprint, solar steam generation and desalination is considered one of the most important technologies to address the increasingly pressing global water scarcity. Despite tremendous progress in the past few years, efficient solar steam generation and desalination can only be achieved for rather limited water quantity with the assistance of concentrators and thermal insulation, not feasible for large-scale applications. The fundamental paradox is that the conventional design of direct absorber−bulk water contact ensures efficient energy transfer and water supply but also has intrinsic thermal loss through bulk water. Here, enabled by a confined 2D water path, we report an efficient (80% under one-sun illumination) and effective (four orders salinity decrement) solar desalination device. More strikingly, because of minimized heat loss, high efficiency of solar desalination is independent of the water quantity and can be maintained without thermal insulation of the container. A foldable graphene oxide film, fabricated by a scalable process, serves as efficient solar absorbers (>94%), vapor channels, and thermal insulators. With unique structure designs fabricated by scalable processes and high and stable efficiency achieved under normal solar illumination independent of water quantity without any supporting systems, our device represents a concrete step for solar desalination to emerge as a complementary portable and personalized clean water solution.