Papers by Author: Huey Ing Chen

Abstract: In this study, hydrogen is generated from water via photoelectrochemical (PEC) process by using CdS/TiO2 photoanode, which is obtained in sequence chemical bath deposition (s-CBD) process. Experimentally, the CdS was deposited on TiO2 NTAs in s-CBD process. First, the TiO2 NTAs is immersed in Cd(NO3)2 and Na2S solution subsequently several cycles followed by annealing to get CdS/TiO2 photoanode. In this work, the factors were studied including immersion cycle, annealing temperature and UV illumination. The surface morphology, crystalline structure and CdS amount were characterized by SEM and XRD. The photoactivities of CdS/TiO2 photoanodes and hydrogen generation rate were investigated by PEC splitting of water. The results showed that the photoanode annealing in air at 300 °C had the highest photoactivity and the crystalline structure of CdS was composed of zinc blende and a small amount of wurtzite. The saturated current density was 6.163 mA/cm2 and the maximum photoelectrochemical conversion was 4.45 % under Xenon lamp (I0 = 100 mW/cm2) illumination. Besides, the photoactivity of CdS(UV)/TiO2 prepared under UV (λmax=253.7 nm) illumination was reduced. This was probably due to the aggregation of CdS. To sum up, the CdS/TiO2 photoanodes for photoelectrochemical splitting water could be a high prospective process of the energy source.

Abstract: In this study, the dependence of Pd/GaAs Schottky diode on the electroless plating (EP) variable is systematically studied. Both alkaline and acidic formulas for electroless Pd depositions are employed for investigations. The correlation between Pd gain size and the manipulation of plating bath composition is constructed. Experimental results show that the performances of Pd/GaAs Schottky diode, electric rectification and hydrogen detection, are largely governed by the Pd grain size. Furthermore, without the interference of sodium ion, the acidic-plated Pd/GaAs diode with intermediate oxide layer exhibits the excellent hydrogen sensing performances from 15 ppm to 1.0 % H2/air.