Yong Sik Kim

Bio: Yong Sik Kim is an academic researcher from Kangwon National University. The author has contributed to research in topics: Lignin & Langmuir. The author has an hindex of 3, co-authored 4 publications receiving 35 citations.

Kraft Lignin Derived Molybdenum Carbide/Nitrogen-Doped Carbon Composite for Efficient Hydrogen Evolution Reaction

Abstract: This paper reports a simple, unique, and eco-friendly fabrication method for composites of molybdenum carbide nanoparticles dispersed on nitrogen-doped carbon supports (Mo2C/NC) by annealing of MoCl5, kraft lignin, urea at 750 ℃ under N2 flow in one pot. Kraft lignin, a by-product from the pulping industry, acted as carbon source for formation of Mo2C and carbon support and a cheap urea provided a nitrogen source for nitrogen-doping to carbon supports. The resultant Mo2C/NC catalysts exhibited high activity with small overpotential (131 mV at 10 mA cm-2) and excellent stability over 3000 potential cycles for hydrogen evolution reaction (HER) in alkaline media. Enhanced HER activity of Mo2C/NC catalyst was attributed to highly active Mo2C nanoparticles and nitrogen-doped carbon (N-doped carbon) providing large surface area and high electrical conductivity.

Circular economy aspects of lignin: Towards a lignocellulose biorefinery

Abstract: Lignin is the second most abundant polymer, which comprises15-30% (dry weight) of total lignocellulosic biomass. Recent studies focused on the effective utilization of lignin biopolymer into a myriad of products such as lignin micro and nanocapsules, biosensors, platform chemicals, pharmaceutical compounds, biopolymers, electrodes in electrochemistry, re-useable adsorbent, resins and biodiesel production through oleaginous microbes. The development of eco-friendly and cost-effective techniques is need-of-the-hour, which can be addressed through the circular economy approach. In this review, the emphasis is laid on integrating bioethanol and biodiesel production and valorizing lignin into various useful products. Besides, prospects of lignin biorefinery coupled with economic policies to be deployed along with the practical implications, have been discussed. Adopting these new pragmatic technologies and policies enables not only the development of inexpensive technologies but also boosts the economic growth of lignocellulosic biorefinery.

Preparation of hybrids of wood sawdust with 3-aminopropyl-triethoxysilane. Application as an adsorbent to remove Reactive Blue 4 dye from wastewater effluents

Abstract: Background Biomass-based materials present low sorption capacity. In order to overcome this disadvantage, chemical modification of these materials is required. Methods Hybrids of biomass-based materials were obtained by reacting (25%-200% weight) 3-aminopropyl-triethoxysilane (APTES) with the biomass Ayous wood sawdust (AW), obtaining the hybrid materials AW@APTES-0.25, AW@APTES-0.50, AW@APTES-1.0, AW@APTES-1.5, and AW@APTES-2.0, that were characterized by hydrophobic/hydrophilic balance, CHN elemental analysis, surface area, TGA, FTIR, and pHpzc. Significant findings For screening purposes, the five materials were tested as adsorbents to remove reactive blue 4 (RB-4) from water. The results showed that AW@APTES-0.5 attained the maximum removal of RB-4. The kinetics and equilibrium data were suitably fitted by the nonlinear General-order kinetic (GO) and Liu equilibrium adsorption models. The maximum amount adsorbed of RB-4 dye was 415.1 mg g − 1 using AW@APTES-0.5 (50 °C). An increase in the Qmax value of AW@APTES-0.5 concerning unmodified AW attained up to 21.6 times. The ΔG° and ΔH° indicated that the adsorption processes of RB-4 onto adsorbents are endothermic and spontaneous, and the magnitude of enthalpy of adsorption (25.10 kJ mol−1) is compatible with the electrostatic attraction mechanism. The adsorbents’ applicability for treating simulated dye effluents showed an excellent efficiency attaining 98.66% removal of the effluent.