Synthesis of graphene/Cu2O thin film photoelectrode via facile hydrothermal method for photoelectrochemical measurement

The process of carbon dioxide (CO2) reduction by using efficient non-precious-metal catalyst to make the process be economical has brought a comprehensive research in the area. In this study, graphene layer in copper foil was easily synthesized using hydrothermal method at temperature 200°C in 3 h duration. Diffraction peaks in XRD at around 29°, 36°, 42° and 74° in the composites correlate to the (110), (111), (200) and (311) crystalline planes of cubic cuprous oxide (Cu2O), while peak at 27° showed the carbon graphitic peak. Raman confirms the presence of the graphene layer on Cu2O. Photoelectrochemical performance test of Graphene/Cu2O demonstrated that the photoelectrocatalyst showing the photocurrent density 9.6 mA cm-2 at -0.8V vs Ag/AgCl. This study demonstrated a potential of semiconductor-based hybrid electrode for an efficient photoelectrocatalytic of CO2 reduction

Aryl diazonium modification for improved graphite fibre brush in microbial fuel cell

Aryl diazonium salts are coupling agents that assist in molecules attachment to interfaces for sensing purposes. Despite not being fully explored and not yet widely applicable for cell-based sensors, the high stability of aryl diazonium salt formed sensing system is highly favorable in biological applications. Carbon-based electrodes are the most commonly used in aryl diazonium modification due to its post grafting stable C-C bond formation. Here, salt bridge based microbial fuel cells (MFCs) were used to study on the effect of aryl diazonium modification on the anode graphite fibre brush. Aryl diazonium salts were in situ generated by the diazonation of p-phenylenediamine with NaNO2 in HCl solution. The electrochemical performance of the aryl diazonium modified graphite brush MFC was measured and compared with the unmodified graphite brush MFC. The power output of the modified graphite brush bioanode was higher (8.33 W/m3) than the unmodified graphite brush (7.60 W/m3) after 20 days of operation with ferricyanide as the catholyte. After 70 days of operation using phosphate buffer solution as the catholyte, the Pmax of modified brush was three times higher (0.06 W/m3) than of the unmodified brush (0.02 W/m3), which indicates an enhanced binding towards the substrate that facilitates a better electron transfer between the microbial and electrode surface

Static stress analysis of membrane electrode assembly (MEA) and gasket in Proton exchange membrane fuel cell stack assembly pressure

The proton exchange membrane fuel cell (PEMFC) system was an electrochemical device that generates electricity through the reaction of hydrogen and oxygen without combustion. Proton Exchange Membrane (PEM) stacks typically consisted of components combined into one unit and equipped with suitable clamping torque. This was to prevent reactant gas leakage and minimize the contact resistance between the gas diffusion medium and the bipolar plate. The combined components consisted of a bipolar plate with a flow field, current collector, membrane electrode assembly (MEA), endplate, and gasket. PEMFC performance was measured concerning its power output, which depends on temperature and the operating pressure. Various efforts had been made to determine the optimal compaction pressure and its distribution through simulations and experiments. Therefore, this research analyzed the static stress of membrane electrode assembly (MEA) and gasket in PEMFC stack assembly pressure. The components’ geometric dimensions and mechanical properties, such as endplates, current collectors, bipolar plates, MEAs, and gaskets, were combined for electricity. Pressure-sensitive film (Fuji measure film prescale) was also used to visualize contact pressure distribution between the MEA and the bipolar plate. The result showed that the color variation of the pressure film indicates the exact distribution of pressure entering the stacking design and the contact image. In conclusion, the detailed contact pressure distribution was an important influence on heat transfer processes and local electrochemical reactions in cell stacks

AN OVERVIEW OF GAS-UPGRADING TECHNOLOGIES FOR BIOHYDROGEN PRODUCED FROM TREATMENT OF PALM OIL MILL EFFLUENT

To date, a high energy demand has led to massive research efforts towards improved gas-separation techniques for more energy-efficient and environmenttally friendly methods. One of the potential alternative energies is biogas produced from the fermentation of liquid waste generated from the oil-extraction process, which is known as palm oil mill effluent (POME). Basically, the gas produced from the POME fermentation process consists mainly of a CO2 and H2 gas mixture. CO2 is known as an anthropogenic greenhouse gas, which contributes towards the climate change phenomenon. Hence, it is crucial to determine a suitable technique for H2 separation and purification with good capability for CO2 capture, as this will reduce CO2 emission to the environment as well. This paper reviewed the current gas-separation techniques that consist of absorption, adsorption and a membrane in order to determine the advantages and disadvantages of these techniques towards the efficiency of the separation system. Crucial aspects for gas-separation techniques such as energy, economic, and environmental considerations are discussed, and a potential biohydrogen and biogas-upgrading technique for industrial POME application is presented and concluded in this paper. Based on the comparison on these aspects, water scrubbing is found to be the best technique to be used in the biogas-upgrading industry, followed by membrane and chemical scrubbing as well as PSA. Hence, these guidelines are justified for selecting the best gas-upgrading technique to be used in palm oil mill industry applications

Reka bentuk dan pembangunan modul STEM Kembara Sains : Chem-E-Car

Kemerosotan bilangan pelajar sekolah yang berminat untuk menceburi aliran Sains, Teknologi, Kejuruteraan dan Matematik (STEM) dilihat sebagai satu masalah yang perlu diatasi dalam kadar segera bagi memastikan hasrat negara untuk menjadi sebuah negara maju berjaya. Dengan itu, kajian ini ingin melihat tahap sambutan yang diberikan oleh pelajar sekolah menengah dengan aktiviti modul STEM Kembara Sains: Chem-E-Car (KEMia) bagi menarik minat pelajar terhadap aliran STEM. Modul STEM KEMia ini diasaskan daripada aktiviti kokurikulum mahasiswa dalam Program Kejuruteraan Kimia iaitu pertandingan Chem-E-Car. Modul STEM KEMia ini menggunakan konsep pertandingan yang memberi peluang kepada pelajar sekolah untuk membangunkan sebuah model kereta yang digerakkan hasil tindak balas kimia. Modul STEM KEMia ini dilihat mampu menguji kemampuan dan daya kreativiti pelajar bersama mahasiswa Kejuruteraan Kimia yang menjadi fasilitator untuk menarik minat mereka kepada STEM. Modul ini juga berkonsepkan pembelajaran secara CDIO (Conceive, Design, Implement and Operate - Memikirkan, Mereka Bentuk, Melaksana dan Mengendalikan) dan pembentukan kemahiran insaniah di kalangan pelajar dan juga fasilitator. Kajian soal-selidik juga dijalankan untuk mendapatkan maklum balas pelajar terhadap program yang telah dilaksanakan. Secara keseluruhan, program ini memberi impak yang positif terhadap pelajar di sekolah seluruh Malaysia dengan sebanyak enam aktiviti program KEMia telah berjaya dijalankan di peringkat sekolah dan kajian maklum balas mendapati sekitar 86% pelajar mendapati program ini menarik