Optical characterization of zinc selenide/graphene oxide composite synthesized via microwave-assisted hydrothermal method

Effect of Sodium Hydroxide Concentration in Synthesizing Zinc Selenide/Graphene Oxide Composite via Microwave-Assisted Hydrothermal Method

“…On the other hand, at higher wavelengths, two peaks are observed around ~1351.2 (D band of graphene oxide) and ~1592.6 cm −1 (G band of graphene oxide). Similar to the previous session, the result is in agreement with the data reported by Lee et al, 2017 who synthesized a cactus-like ZnSe/GO composite [20]. Therefore, the proposed reaction mechanism of the formation of ZnSe, which is similar to Feng et al [29] is described as below:N 2 H 4 + H 2 O ↔ N 2 H 5 + + OH − > N 2 H 5 + + 2Se + 5OH − → N 2 + 2Se 2− + 5H 2 O ZnCl 2 → Zn 2+ + 2Cl − Zn 2+ + 2OH − → Zn(OH) 2 Zn(OH) 2 + 2OH − → Zn(OH) 4 2− Zn(OH) 4 2− + DEA → [Zn(OH) 4 2− DEA] [Zn(OH) 4 2− DEA] + Se 2− → ZnSe + 4OH − + DEA…”

“…The purity of the ZnSe also increased from 88.2% to 100.0% when the concentration of NaOH increased from 2 M to 4 M. Meanwhile, the percentage of ZnSe decreased to 27.7% and 6.0% when the concentration of NaOH increased to 5 M and 6 M. Secondary phases such as selenium, zinc oxide and zinc bis(hydrogenselenate (IV)) tetrahydrate (Zn(HSeO 3 )2(H 2 O) 4 ) (ICSD 98-003-3368) were detected. Moreover, the crystallite size of the sample was also calculated using Scherrer’s equation [20]:L= Kλ/(βcosθ) where L is the crystallite size, K is a Scherrer constant (K = 0.89), λ is X-ray wavelength, β is full-width half maximum of the peak and θ is the Bragg’s angle. The crystallite size was calculated with respect to the dominant (111) plane.…”

“…The previously reported method was used in this study [20]. In detail, a graphene oxide solution was prepared by dispersing (2.5 ± 0.1) mg of graphene in 25 mL of deionized water.…”

“…By mixing graphene oxide with a ZnSe nanoparticle, it can be observed that the graphene oxide layer can reduce the recombination of electron-electron hole pairs during the photon absorption process. It is believed that the lifetime of the photogenerated carriers in samples also improved along with their potential use in optoelectronic applications [20,21]. In addition, there is a lot of research that has reported on synthesizing a chalcogenide semiconductor by varying parameters such as the types of precursors, temperature, reaction time, types of surfactants and the concentration of surfactants.…”

New generation of oxide-based nanoparticles for the applications in early cancer detection and diagnostics

“…Local interaction of microwaves with precursors allowed crystallization of new and metastable phases. These properties lead to the synthesis of many new materials including carbon nanotubes [250], zeolites [251], composites [252] and semiconductor nanoparticles [253]. Hereby, the oxides synthesis will be discussed in detail, as its products have potential applicability for biological sciences and medicine [254].…”