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Recent approaches to address more efficient method on storing hydrogen by using adsorbent materials has been done. The hydrogen adsorption on silicon has been studied through molecular dynamics simulations and experiment by researchers. We conducted molecular dynamics simulation using a Lennard-Jones potential to demonstrate the hydrogen adsorption capability of silicon surface (001) and (111) with various temperature applied. The amount of hydrogen adsorbed by silicon surfaces are higher as entropy of the system decreases. Without considering entropy, Si (111) has higher adsorption capability due to its lower energy surface than Si (001).

Nitrogen is an element that is widely found in nature can be used as a gas that is absorbed to help characterize materials, especially on the surface of the material. According to Brunauer – Emmet - Teller (BET) is a theory where nitrogen is used as a gas characterizing material because of its ability to high purity and can interact with solid elements and inert. BET can only produce quantitative data and does not show adsorption phenomena. Molecular dynamics simulation is conducted to observe the phenomena during nitrogen adsorption in amorphous silica, a porous material with a large surface area. In this study, the molecular dynamics simulations are arranged in a state of isotherm, where the temperature used is three variables: 77 K, 100 K, and 150 K in the variation of pressure used 1, 3, 5, 7, and 10 atm for each equilibrium. In molecular dynamics simulation to simulate the interaction between atoms based on Coulomb force is using Lennard-Jones Potential. Based on the simulation results obtain, it was found that at 77 K temperature had the optimal ability to adsorb nitrogen compared to 100 K and 150 K. The higher the pressure given in the system, it will increase the amount of nitrogen adsorbed.

The high development of science and technology affects the economic growth and industrialization process. The industrialization process produces industrial waste which contain heavy metal such as copper (Cu). This industrial waste can harm the environment surronding industrial areas where 15 million or 6% of the Indonesian population live. In order to overcome this problem, mesoporous silica material Santa Barbara Amorphous-15 (SBA-15) is used as an adsorbent. SBA-15 was synthesized through sol gel process using tetraorthosilicate as precursor, Pluronic 123 triblock copolymer as template, and (3-chloropropyl)trimethoxysilane (CPTMS) as functionalized agent. CPTMS was used to modify the SBA-15 surface in order to improve the materials as adsorbent. The materials were characterized using SAXRD and TEM to study material’s cristallinity and pore structure, the presence of organic group was examined using FTIR, the surface area of SBA-15 and SBA-15 CPTMS were characterized using Brunauer Emmett Teller (BET) N2 adsorption isotherm test at 77 K, and the ions concentration in solution after adsorption process was determined using AAS. The crystal structure of SBA-15 and SBA-15 CPTMS was found 2D heksagonal with a more regular SBA-15 pore structure than SBA-15 CPTMS. The surface area of SBA-15-CPTMS was found to be lower than SBA-15, 711.061 m2/g in comparison to 831.996 m2/g. However, in copper adsorption test, it was found that SBA-15-CPTMS has higher adsorption ability.