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Exploring ethynyl-based chalcones as green semiconductor materials for optical limiting interests

2024 , Wan M. Khairul , Fatimah Hashim , Rafizah Rahamathullah , Mas Mohammed , Siti Aisyah Razali , Syed Ahmad Tajudin Tuan Johari , Suha Azizan

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Fused aromatic disubstituted azomethine as organic additives in NH4SCN doped CMC based electrolyte film

2023 , Rafizah Rahamathullah , Jia Kai Low , Wan M. Khairul , Rozana Aina Maulat Osman , Mohd Ikmar Nizam Mohamad Isa

The remarkable progress of organic dye based on donor-Ï€-acceptor concepts has been extensively studied to enhance carrier mobility, electrical performance and can perform function at an optimum level in advanced electrochemical energy devices. In this study, new organic additive for solid polymer electrolyte (SPE) has been successfully synthesized by incorporating fused aromatic azomethine (-CH=N-) dye in carboxy methylcellulose (CMC) with ammonium thiocyanate (NH4SCN) based electrolyte. Assessment of the synthesized additive has been physico-chemically characterized via Fourier transform infrared (FT-IR), UV-visible (UV-vis), 1D Nuclear Magnetic Resonance (NMR) and thermogravimetric (TGA) analysis. Besides, DFT calculation revealed that the value of HOMO-LUMO gap exhibits semiconductor properties with the activation energy of 3.135 eV. The investigation of their capability as organic additive SPE has been discovered by incorporating CMC-NH4Cl via solution-casting technique. The structural analysis was conducted to study the effect of the atomic structure in correlation towards ionic and conductivity of newly develop SPE. The ionic conductivity of SPEs system has been measured using Impedance Spectroscopy with various weight percentage (wt%) of additive. The highest conductivity of SPEs at 303K was approximately ~10-3 Scm-1 at 0.6 wt%. As a result, the incorporation of fused aromatic azomethine into the SPE has a great potential to be used for electrochemical device application.

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Deciphering ethynyl single crystal for NLO applications: Synergistic studies on the structural, Hirshfeld surface, photophysical and DFT assessment

2024 , Wan M. Khairul , Mas Mohammed , Rafizah Rahamathullah , Muhamad Fikri Zaini , Suhana Arshad , Abdul Razak Ibrahim , Fazira Ilyana Abdul Razak , Suhaila Sapari

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An integrated DFT calculation and adsorption study of desiccated coconut waste-based biochar in CO2 environment

2024-01-01 , Rafizah Rahamathullah , Zakaria D.S. , Siti Khalijah Mahmad Rozi , Hairul Nazirah Abdul Halim , Razak F.I.A. , Sapari S.

Abstract: This study presents a new series of amine-functionalized biochar derived from desiccated coconut waste (amine-biochar@DCW) as potential CO2 adsorbents. The CO2 adsorption experiment revealed that TETA-biochar@DCW had the highest adsorption capacity of 61.78 mg/g. Prior to the experimental studies, Density Functional Theory (DFT) was conducted at B3LYP/6-31G (d,p) to evaluate the energy band gap, global chemical reactivity descriptors (GCRD), and molecular electrostatic potentials (MEP) to compare the experimental findings. The results from the simulated data indicate that TETA-biochar@DCW has the lowest HOMO–LUMO gap at 2.7890 eV before adsorption, and it increases after CO2 adsorption occurs. The 3D plots from MEP also show that TETA-biochar@DCW is a reactive adsorbent for CO2 gases. Overall, the theoretical and experimental results of the amine-biochar@DCW suggest its potential as a promising and cost-effective adsorbent for CO2 capture. Highlights: • Newly prepared amine-biochar@DCW was assessed as CO2 adsorbents. • TETA-biochar@DCW presents the highest CO2 capture capacity. • TETA substituents significantly reduce the HOMO-LUMO gap values. • 3D MEP plots confirm the adsorption ability of TETA-biochar@DCW towards CO2 gases. Graphical Abstract: [Figure not available: see fulltext.]