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

• Published in: Materials Vol. 12; no. 14; p. 2295
• Main Authors: Lee, Han Kee, Talib, Zainal Abidin, Mamat @ Mat Nazira, Md Shuhazlly, Wang, EnZe, Lim, Hong Ngee, Mahdi, Mohd Adzir, Ng, Eng Khoon, Yusoff, Norita Mohd, AL-Jumaili, Batool Eneaze, Liew, Josephine Ying Chyi
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.07.2019; MDPI
• Subjects: Caustic soda; Composite materials; Energy; Energy gap; Graphene; Hydrothermal crystal growth; Hydroxyl ions; Microwaves; Morphology; Nanocomposites; Nanoparticles; Optical properties; Particle size; Photocatalysis; Purity; Quantum dots; Selenium; Sodium hydroxide; Surfactants; Synthesis; Zinc oxides; Zinc selenide; Malaysia; Germany; Microwave-assisted hydrothermal method; NaOH concentration; Optical band gap; ZnSe/GO composite
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12142295

The effect of NaOH solution on the formation of nanoparticles has been the subject of ongoing debate in selenium-based material research. In this project, the robust correlation between the mechanistic growth of zinc selenide/graphene oxide (ZnSe/GO) composite and the concentration of NaOH are elucidated. The ZnSe/GO composite was synthesized via microwave-assisted hydrothermal method and the concentrations of NaOH are controlled at 2 M, 3 M, 4 M, 5 M and 6 M. The XRD spectra show that the crystal phases of the samples exhibited a 100% purity of ZnSe when the concentration of sodium hydroxide (NaOH) was set at 4 M. The further increase of NaOH concentration leads to the formation of impurities. This result reflects the essential role of hydroxyl ions in modifying the purity state of ZnSe/GO composite. The optical band gap energy of ZnSe/GO composite also decreased from 2.68 eV to 2.64 eV when the concentration of NaOH increased from 2 M to 4 M. Therefore, it can be concluded that the optimum concentration of NaOH used in synthesizing ZnSe/GO composite is 4 M. This project provides an alternative green method in the formation of a high purity ZnSe/GO composite.