Mobeen Haneef

Bio: Mobeen Haneef is an academic researcher from National University of Science and Technology. The author has contributed to research in topics: Materials science & Thermoelectric effect. The author has an hindex of 2, co-authored 2 publications receiving 182 citations.

Preparation of different heteroatom doped graphene oxide based electrodes by electrochemical method and their supercapacitor applications

Abstract: In this study, one-step preparation method of different heteroatom (-S, -N, -Cl) doped graphene oxide electrodes were achieved as electrode materials for the purpose of high-capacity supercapacitors Microscopic, spectroscopic, and electrochemical methods were used to characterize the prepared electrodes Formation of -ClO2, -ClO3, -SOx (x:2, 3) and -NO2 groups on the graphene oxide-based electrodes were determined by X-ray photoelectron spectroscopy analysis Detail reaction mechanisms were suggested for the formation of these groups on the electrode surface for the first time in the literature Different surface properties of graphene oxide structures in the electrodes were investigated by scanning electron microscopy and atomic force microscopy Electrochemical behaviors of the prepared electrodes were characterized by cyclic voltammetry and electrochemical impedance spectroscopy Sulphur, nitrogen, and chlorine doped graphene oxide electrodes were used as electrode materials for supercapacitor applications Since different heteroatom doped graphene oxide-based electrodes showed different capacitive behavior Areal capacitances of -S, -N and -Cl doped graphene oxide electrodes were determined as 2064 mFcm−2, 5332 mFcm−2 and 1098 mFcm−2, respectively with 10 mAcm−2

UV light irradiation enhanced gas sensor selectivity of NO2 and SO2 using rGO functionalized with hollow SnO2 nanofibers

Abstract: Herein, to enhance selective detection of NO2 and SO2 using a single device, an ultraviolet (UV) light activated gas sensor has been reported based on reduced graphene oxide (rGO) functionalized with hollow SnO2 nanofibers (NFs) at room temperature. The porous hollow SnO2 NFs are synthesized using electrospinning and calcination treatment, then different contents of SnO2 are introduced to rGO for preparation of rGO/SnO2 nanocomposites by facile magnetic stirring and ultrasonic treatment. The rGO/SnO2 samples reveal obvious sensing response, great reversibility and good humidity resistance to target gases at ppm level. Under different intensities of UV light illumination, gas sensing properties of rGO/SnO2 are studied to explore the photoexcited sensing behaviors. The greatly enhanced selective detection to NO2 (102%) and SO2 (11%) is achieved with a response ratio of 9.3 by using UV light illumination. The results show sensor response and selectivity can be improved using appropriate intensity of excitation light, demonstrating significant modulation effect of UV light assistance on gas detection. The mechanism may be attributed to light motivated electron-hole pairs due to built-in electric fields under UV light illumination, which can be captured by target gases and lead to UV controlled gas sensing performance.