Research Outputs
Z-scheme configured iron oxide/g-C3N4 nanocomposite system for solar-driven H2 production through water splitting
A nanocomposite composed of α-Fe2O3/g-C3N4 is synthesized using a modified ultrasonication approach, which engineered a robust interfacial contact in the system. Phase formation and morphological features are confirmed via XRD and electron-microscopy techniques. XPS revealed the native oxidation states of the elements and chemisorption-mediated interactions in the system. This developed composite produced hydrogen at a rate of 1494 μmolg− 1 h− 1, which is around 6.6 times higher than the g-C3N4 system. The observed enhancement is attributed to the Z-scheme configuration, leading to the suitable band edge alignments, charge separation and extended lifetime of the carriers in the composite.
Simultaneous electrochemical determination of dopamine and epinephrine using gold nanocrystals capped with graphene quantum dots in a silica network
Gold nanocrystals (AuNCs) were synthesized by economical and green strategy in aqueous medium by using N[3(trimethoxysilyl)propyl]ethylenediamine (TMSPED) as both a reducing and stabilizing mediator to avoid the aggregation of gold nanocrystals. Then, the AuNCs were capped with graphene quantum dots (GQDs) using an ultrasonic method. The resulting nanocomposites of GQD-TMSPED-AuNCs were characterized by X-ray photoelectron, X-ray diffraction, Raman, UV-vis and FTIR spectroscopies. The size and shape of the nanocomposites were confirmed by using transmission electron microscopy and atomic force microscopy. The GQD-TMSPED-AuNCs placed on a glassy carbon electrode enable simultaneous determination of dopamine (DA) and epinephrine (EP) with peak potentials at 0.21 and 0.30 V (vs. Ag/AgCl). The response is linear in the 5 nM – 2.1 μM (DA) and 10 nM – 4.0 μM (EP) concentration ranges, with detection limits of 5 and 10 nM, respectively. The sensor shows good selectivity toward DP and EP in the presence of other molecules, facilitating its rapid detection in practical applications.