Study on reflux method for morphology control of cadmium sulfide nanorods
Authors: Ngoc Bao Tri Pham, Thanh Tam Nguyen, Cheng-Kuo Tsai, Cong Khanh Tran, Jao-Jia Horng
Abstract:
Cadmium sulfide (CdS) has been widely applied in electrochemical detection and photocatalyst application with its low band gap Eg~ 2.5 eV as well as its conduction band edge potential lower than the H2O/H2 electrode potential. Those properties could yield more sunlight collection and transform solar energy into chemical energy under solar irradiation. Many methods have been developed to synthesis CdS, such as the reflux method of synthesizing CdS nano rods (NRs) with water as a solvent, thioglycolic acid (TGA) as a capping agent, and sodium sulfide as the sulfur source. CdS NRs were successfully produced with changing parameters of the precursor concentration, solution pH, reaction time, and the annealing temperature. The TGA concentration and solution pH could change the formation of the high-density template of NRs with the wurtzite phase at 1.54µm in length and 0.10 µm in diameter after reaction time of 36 h. Furthermore, our results also showed that the crystalline structure of CdS becoming annealed at a high temperature 400 ºC for 1 h with the best quality in crystalline and morphology. This improved reflux method is expected to be a simple and facile CdS NRs approach to synthesis photocatalysts to apply in various environmental treatment and energy production applications.
Keywords: CdS, reflux, pH, reaction time, annealing temperature
