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Rapid Reduction of Ultrathin Films of Graphene Oxide on Large-Area Silicon Substrate

150 150 MIMOS Berhad

Authors:

Marianah Masrie, Siti Aishah Mohamad Badaruddin, Mohd Rofei Mat Hussin,Nik Mohamad Razali Mohd Nor and Jeremy Joe

 

Abstract:

Graphene oxide thin films were fabricated on 8-inch silicon/silicon dioxide (Si/SiO2) wafersfor nanoelectronic applications. The fabrication was performed using an ultrasonic spray coating method and reducedby rapid thermal processing (RTP). The micrometer sizeddroplets from an ultrasonic spray of stable dispersion Graphene Oxide (GO) in ethanol form uniforms films on large-area silicon substrates. Optical microscope images clearly showed uniform thin films resulting from the overlappedof GO dispersion droplets. The chemical and structural parameter characterization were performed by field emissionscanning electron microscopyand X-ray photoelectron spectroscopy (XPS). The spraycoatingprocess usinganultrasonicatomizersystem with optimum parameters and the thermal reduction process using RTP at 1100 °C produceslow sheet resistance values ranging from 1 to 4kOhms/sq with non-uniformity less than 20%.

 

Source:

International Conference on Semiconductor Materials and Technology (ICoSeMT 2019), Penang

A smart solution to poaching in Royal Belum

150 150 MIMOS Berhad

Poaching of wildlife is rife In the country due to the demand for their meat and purported medicinal properties. This is common knowledge among conservationists and environmentalists, if not the general public.

Numerous wildlife species, such as the Malayan tiger, pangolin, sun bear, deer and exotic birds, are targeted. As for flora, again,anything that makes money is a target such as the iconic Rafflesia as well as rare rainforest trees like the gaharu tree or agarwood.

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QCM Coupled Resonating Systems under Vacuum – Sensitivity and Characteristics

150 150 MIMOS Berhad

Authors:

Mohammad Ali Mohammadzadeh Kashan; Vineetha Kalavally; Purabi Mazumdar; Hing Wah Lee and N. Ramakrishnan

 

Abstract:

We present  the  underlying  physics in  the resonance frequency  characteristics  of a bare  quartz  crystal  microbalance(QCM) and a QCM-micro pillar based coupled resonator sensor (QCM-CRS)  when  they  were  subjected  to pressure changes in  a vacuum   chamber.   The   QCMs experienced   an   increase   in resonance frequency with decrease in pressure due to an inverse mass loading effect  introduced  on  the  QCM  surface. However, when  the  pressure  (below  atmospheric  pressure)  dominated  the mass  loading,  the resonance  frequency of  QCMs  decreased.  A sensitivity  increase  of  11  times  to    the  pressure  changes  was observed for case of QCM-CRS  made of resonating micropillars attached  around  the  central  region  of  the  electrode. Also  the resonance   frequency   shift   was linear for   pressure   changes between  31 kPa and 71kPa,  demonstrating  the  possibility  of employing  QCM-CRS  vacuum  detector  element.  The  proposed sensor element is envisioned to have wide industrial applications ranging  from  detecting  vacuum  in chambers  used  in  coating systems to crack detection in closed chambers.

 

Source:

IEEE Sensors Journal

 

Heteroatom Nitrogen- and Boron-Doping as a Facile Strategy to Improve Photocatalytic Activity of Standalone Reduced Graphene Oxide in Hydrogen Evolution

150 150 MIMOS Berhad

Authors:

Lutfi K. Putri, Boon-Junn Ng, Wee-Jun Ong , Hing Wah Lee, Wei Sea Chang, and Siang-Piao Chai

 

Abstract:

Owing to its superior properties and versatility, graphene has been proliferating the energy research scene in the past decade. In this contribution, nitrogen (N) and boron (B) doped reduced graphene oxide (rGO) variants were investigated as a sole photocatalyst for the green production of H2 and their properties with respect to photocatalysis were elucidated for the first time. N, B rGOs were facilely prepared via the pyrolysis of graphene oxide with urea and boron anhydride as their respective dopant source. The pyrolysis temperature was varied (600oC800oC for NrGO and 800oC1000oC for BrGO) in order to modify dopant loading percentage(%) which was found to be influential to photocatalytic activity. NrGO600 (8.26 N at%) and BrGO1000 (3.59 B at%), which holds the highest at% from each of their party, exhibited the highest H2 activity. Additionally, the effects of the nature of N and B bonding configuration in H2 photoactivity were also examined. This study demon strates the importance of dopant atoms in graphene, rendering doping as an effective strategy to  bolster  photocatalytic  activity  for standalone graphene derivative photocatalysts. 

 

Source:

ACS Appl. Mater. Interfaces

Nitrogen-doped multiwalled carbon nanotubes decorated with copper(I) oxide nanoparticles with enhanced capacitive properties

150 150 MIMOS Berhad

Authors:

Syed Muhammad Hafiz, Khairul Anuar and Huang Nay Ming

 

Abstract:

We  report  on  the  enhanced  capacitive  properties  of  a  copper(I)  oxide nanoparticle (Cu2O NP)-decorated multiwalled carbon nanotube (MWCNT) forest with nitrogen (N) doping. A careful in situ solid-state dewetting and plasma doping method was developed that ensured homogeneous decoration and contamination-free Cu2O NPs with N doping on the nanotube sidewalls. The morphology and structure of the hybrid materials were characterised by scanning electron microscopy, transmission electron microscopy, energy-dis-persive spectroscopy, Raman spectroscopy and X-ray photoemission spectroscopy.  The electrochemical performance of the hybrid materials  was investigated by cyclic voltammetry and galvanostatic charge/discharge tests in a 0.1 M Na2SO4electrolyte. The electrochemical tests demonstrated that the Cu2O NP/N-MWCNT electrode exhibits a specific capacitance up to 132.2 F g-1 at a current density of 2.5 A g-1, which is 30% higher than that of the pure MWCNT electrode. Furthermore, the electrode could retain the specific capacitance at 85% stability over 1000 cycles. These observations along with the simple assembly method for the hybrid materials suggest that the Cu2O NP/N-MWCNT could be a promising electrode for supercapacitor applications.

 

Source:

Journal of Materials Science, v.52, N.8, April 2017